TinyCLR OS V2 RC1 LoRa library Part4

Interrupts Revisited

In my last post I had two approaches for fixing the issue with transmit interrupts. As I was sorting out the configuration for my Fezportal device and SS20100 Dev board(both sockets) with a Cascologix MikroBus LoRa click I had similar issues with both receive and transmit.

SC20100 Dev Rev A with Cascologix Click in socket1
Fezportal with Cascologix click

I noticed the extra RegIrqFlags 0X58, Receive-Message in the debugging output.

The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X58
Receive-Message
Received 23 byte message  �LoRaIoT1N3WT 20.5,H 86
Transmit-Done
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done

This was with the modified device write methods so I tried changing the Serial Peripheral Interface(SPI) configuration.

public RegisterManager(string spiPortName,  int chipSelectPin, int clockFrequency = 500000)
{
	GpioPin chipSelectGpio = GpioController.GetDefault().OpenPin(chipSelectPin);

	var settings = new SpiConnectionSettings()
	{
		ChipSelectType = SpiChipSelectType.Gpio,
		ChipSelectLine = chipSelectGpio,
		Mode = SpiMode.Mode0,
		ClockFrequency = clockFrequency,
		ChipSelectActiveState = false,
		ChipSelectHoldTime = new TimeSpan(1),
	};

	SpiController spiController = SpiController.FromName(spiPortName);

	rfm9XLoraModem = spiController.GetDevice(settings);
}

When I added the ChipSelectHoldTime (even the smallest possible one) the code worked as expected.

The thread '' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 23 byte message �LoRaIoT1N3WT 20.5,H 87
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 4!
RegIrqFlags 0X08
Transmit-Done

At this point I have run out of ideas so I will release the code this fix.

TinyCLR OS V2 RC1 LoRa library Part3

Why are Transmit Interrupts broken?

The receive using interrupts appeared to be working but transmit with interrupts I could only send a couple of messages before confirmations stopped.

I had read about restrictions for interrupts pins e.g. PA1 & PB1 can’t be used at the same time, but PA1 and PB2 can, which got me thinking…

In my dragino shield based setup Arduino D2(PA1) is the interrupt(IRQ) line and Arduino D10(PB1) is chip select (CS) so I changed the pins with jumper wires just incase.

Fezduino connected to Dragino LoRa shield with jumpers

I tried several different configurations of CS and IRQ pins and none worked.

On other embedded .net platforms I have written Serial Peripheral Interface(SPI) based drivers for (e.g. Wilderness Labs Meadow and the nanoFramework) there had been issues with the use of device.Write vs. device. TransferFullDuplex (or its equivalent).

The RegisterWriteByte method in the event handler appeared to be the problem so I tried modifying it.

public void RegisterWriteByte(byte address, byte value)
{
   byte[] writeBuffer = new byte[] { address |= RegisterAddressWriteMask, value };
   Debug.Assert(rfm9XLoraModem != null);

   rfm9XLoraModem.Write(writeBuffer);
}

Became

public void RegisterWriteByte(byte address, byte value)
{
   byte[] writeBuffer = new byte[] { address |= RegisterAddressWriteMask, value };
   byte[] readBuffer = new byte[2];
   Debug.Assert(rfm9XLoraModem != null);

   rfm9XLoraModem.TransferFullDuplex(writeBuffer, readBuffer);
}

In the diagnostic output I could see confirmations arriving

The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 4!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 5!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 6!
RegIrqFlags 0X08
Transmit-Done

This was clue it might be a timing problem, so I took a closer look at how the SPI port was configured. After some experimentation I found that by adding a small ChipSelectHoldTime the .Write statements worked.

When I went back and checked there had also been some timing “tweaks” required to get my .Net Microframework LoRa library to work reliably.

public Rfm9XDevice(string spiPortName, int chipSelectPin, int resetPin, int interruptPin)
{
   GpioController gpioController = GpioController.GetDefault();

   GpioPin chipSelectGpio = gpioController.OpenPin(chipSelectPin);

   var settings = new SpiConnectionSettings()
   {
      ChipSelectType = SpiChipSelectType.Gpio,
      ChipSelectLine = chipSelectGpio,
      Mode = SpiMode.Mode0,
      ClockFrequency = 500000,
      ChipSelectActiveState = false,
      //ChipSelectHoldTime = new TimeSpan(50),
      //ChipSelectHoldTime = new TimeSpan(25),
      //ChipSelectHoldTime = new TimeSpan(10),
      ChipSelectHoldTime = new TimeSpan(5),
      //ChipSelectHoldTime = new TimeSpan(1),
   };

   SpiController spiController = SpiController.FromName(spiPortName);

   rfm9XLoraModem = spiController.GetDevice(settings);

   // Factory reset pin configuration
   GpioPin resetGpioPin = gpioController.OpenPin(resetPin);
   resetGpioPin.SetDriveMode(GpioPinDriveMode.Output);
   resetGpioPin.Write(GpioPinValue.Low);
   Thread.Sleep(10);
   resetGpioPin.Write(GpioPinValue.High);
   Thread.Sleep(10);

   // Interrupt pin for RX message & TX done notification 
   InterruptGpioPin = gpioController.OpenPin(interruptPin);
   InterruptGpioPin.SetDriveMode(GpioPinDriveMode.Input);

   InterruptGpioPin.ValueChanged += InterruptGpioPin_ValueChanged;
}

In the diagnostic output I could see confirmations arriving

...
Sending 16 bytes message Hello LoRa 1115!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1116!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1117!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1118!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1119!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1120!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1121!
RegIrqFlags 0X08
Transmit-Done
Sending 16 bytes message Hello LoRa 1122!
RegIrqFlags 0X08
The program '[13] TinyCLR application: Managed' has exited with code 0 (0x0).

After some soak testing it looks like the ChipSelectHoldTime modification works pretty reliably but I will need watch for issues.

EDIT: After a long walk I have updated the code to use TransferFullDuplex rather than add a ChipSelectHoldTime.

TinyCLR OS V2 RC1 LoRa library Part2

Receive and Transmit

The first step was to confirm the transmission of messages with polled completion confirmation was working as expected.

   class Program
   {
      static void Main()
      {
#if TINYCLR_V2_SC20100DEV
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi3, SC20100.GpioPin.PA13, SC20100.GpioPin.PA14);
#endif
#if TINYCLR_V2_FEZDUINO
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi6, SC20100.GpioPin.PB1, SC20100.GpioPin.PA15);
#endif
         int SendCount = 0;

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         // More power PA Boost
         rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

         rfm9XDevice.RegisterDump();

         while (true)
         {
            rfm9XDevice.RegisterWriteByte(0x0E, 0x0); // RegFifoTxBaseAddress 

            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

            string messageText = $"Hello LoRa {SendCount += 1}!";
               
            // load the message into the fifo
            byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
            rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo

            // Set the length of the message in the fifo
            rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength

            Debug.WriteLine($"Sending {messageBytes.Length} bytes message {messageText}");
            /// Set the mode to LoRa + Transmit
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

            // Wait until send done, no timeouts in PoC
            Debug.WriteLine("Send-wait");
            byte IrqFlags = rfm9XDevice.RegisterReadByte(0x12); // RegIrqFlags
            while ((IrqFlags & 0b00001000) == 0)  // wait until TxDone cleared
            {
               Thread.Sleep(10);
               IrqFlags = rfm9XDevice.RegisterReadByte(0x12); // RegIrqFlags
               Debug.WriteLine(".");
            }
            rfm9XDevice.RegisterWriteByte(0x12, 0b00001000); // clear TxDone bit
            Debug.WriteLine("Send-Done");

            Thread.Sleep(30000);
         }
      }
   }

The diagnostic output shows messages being sent and on another device I could see the messages arriving. I do wonder why the first message often takes so long to send?

Register dump
Register 0x00 - Value 0Xc3
Register 0x01 - Value 0X80
Register 0x02 - Value 0X1a
Register 0x03 - Value 0X0b
Register 0x04 - Value 0X00
Register 0x05 - Value 0X52
Register 0x06 - Value 0Xe4
Register 0x07 - Value 0Xc0
Register 0x08 - Value 0X00
Register 0x09 - Value 0X80
Register 0x0a - Value 0X09
Register 0x0b - Value 0X2b
Register 0x0c - Value 0X20
Register 0x0d - Value 0X01
Register 0x0e - Value 0X80
Register 0x0f - Value 0X00
Register 0x10 - Value 0X00
Register 0x11 - Value 0X00
Register 0x12 - Value 0X00
Register 0x13 - Value 0X00
Register 0x14 - Value 0X00
Register 0x15 - Value 0X00
Register 0x16 - Value 0X00
Register 0x17 - Value 0X00
Register 0x18 - Value 0X10
Register 0x19 - Value 0X00
Register 0x1a - Value 0X00
Register 0x1b - Value 0X00
Register 0x1c - Value 0X00
Register 0x1d - Value 0X72
Register 0x1e - Value 0X70
Register 0x1f - Value 0X64
Register 0x20 - Value 0X00
Register 0x21 - Value 0X08
Register 0x22 - Value 0X01
Register 0x23 - Value 0Xff
Register 0x24 - Value 0X00
Register 0x25 - Value 0X00
Register 0x26 - Value 0X04
Register 0x27 - Value 0X00
Register 0x28 - Value 0X00
Register 0x29 - Value 0X00
Register 0x2a - Value 0X00
Register 0x2b - Value 0X00
Register 0x2c - Value 0X00
Register 0x2d - Value 0X50
Register 0x2e - Value 0X14
Register 0x2f - Value 0X45
Register 0x30 - Value 0X55
Register 0x31 - Value 0Xc3
Register 0x32 - Value 0X05
Register 0x33 - Value 0X27
Register 0x34 - Value 0X1c
Register 0x35 - Value 0X0a
Register 0x36 - Value 0X03
Register 0x37 - Value 0X0a
Register 0x38 - Value 0X42
Register 0x39 - Value 0X12
Register 0x3a - Value 0X49
Register 0x3b - Value 0X1d
Register 0x3c - Value 0X00
Register 0x3d - Value 0Xaf
Register 0x3e - Value 0X00
Register 0x3f - Value 0X00
Register 0x40 - Value 0X00
Register 0x41 - Value 0X00
Register 0x42 - Value 0X12
Sending 13 bytes message Hello LoRa 1!
Send-wait
.
.
.
.
.
Send-Done
Sending 13 bytes message Hello LoRa 2!
Send-wait
Send-Done
Sending 13 bytes message Hello LoRa 3!
Send-wait
Send-Done
Sending 13 bytes message Hello LoRa 4!
Send-wait
Send-Done
Sending 13 bytes message Hello LoRa 5!
Send-wait
Send-Done
Sending 13 bytes message Hello LoRa 6!
Send-wait
Send-Done

The second step was to confirm the polled reception of messages was working as expected.

   class Program
   {
      static void Main()
      {
#if TINYCLR_V2_SC20100DEV
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi3, SC20100.GpioPin.PA13, SC20100.GpioPin.PA14);
#endif
#if TINYCLR_V2_FEZDUINO
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi6, SC20100.GpioPin.PB1, SC20100.GpioPin.PA15);
#endif


         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

         rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

         while (true)
         {
            // Wait until a packet is received, no timeouts in PoC
            Debug.WriteLine("Receive-Wait");
            byte irqFlags = rfm9XDevice.RegisterReadByte(0x12); // RegIrqFlags
            while ((irqFlags & 0b01000000) == 0)  // wait until RxDone cleared
            {
               Thread.Sleep(100);
               irqFlags = rfm9XDevice.RegisterReadByte(0x12); // RegIrqFlags
               //Debug.Write(".");
            }
            Debug.WriteLine("");
            Debug.WriteLine($"RegIrqFlags 0X{irqFlags:X2}");
            Debug.WriteLine("Receive-Message");
            byte currentFifoAddress = rfm9XDevice.RegisterReadByte(0x10); // RegFifiRxCurrent
            rfm9XDevice.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

            byte numberOfBytes = rfm9XDevice.RegisterReadByte(0x13); // RegRxNbBytes

            byte[] messageBytes = rfm9XDevice.RegisterRead(0x00, numberOfBytes); // RegFifo

            rfm9XDevice.RegisterWriteByte(0x0d, 0);
            rfm9XDevice.RegisterWriteByte(0x12, 0b11111111); // RegIrqFlags clear all the bits

            string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
            Debug.WriteLine($"Received {messageBytes.Length} byte message {messageText}");

            Debug.WriteLine("Receive-Done");
         }
      }
   }

The diagnostic output shows messages being received from one of my other devices.

The thread ” (0x2) has exited with code 0 (0x0).
Receive-Wait

RegIrqFlags 0X50
Receive-Message
Received 23 byte message �LoRaIoT1N3WT 18.8,H 78
Receive-Done
Receive-Wait

RegIrqFlags 0X50
Receive-Message
Received 23 byte message �LoRaIoT1N3WT 18.8,H 78
Receive-Done
Receive-Wait

The next step was to confirm the interrupt driven reception of messages was working as expected.

   class Program
   {
      static void Main()
      {
#if TINYCLR_V2_SC20100DEV
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi3, SC20100.GpioPin.PA13, SC20100.GpioPin.PA14, SC20100.GpioPin.PE4);
#endif
#if TINYCLR_V2_FEZDUINO
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi6, SC20100.GpioPin.PB1, SC20100.GpioPin.PA15, SC20100.GpioPin.PA1);
#endif

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

         rfm9XDevice.RegisterWriteByte(0x40, 0b00000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady

         rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

         rfm9XDevice.RegisterDump();

         Debug.WriteLine("Receive-Wait");
         Thread.Sleep(Timeout.Infinite);
      }
   }

      private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e)
      {
         if (e.Edge != GpioPinEdge.RisingEdge)
         {
            return;
         }

         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         Debug.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");
         if ((irqFlags & 0b01000000) == 0b01000000)  // RxDone 
         {
            Debug.WriteLine("Receive-Message");
            byte currentFifoAddress = this.RegisterReadByte(0x10); // RegFifiRxCurrent
            this.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

            byte numberOfBytes = this.RegisterReadByte(0x13); // RegRxNbBytes

            // Get number of bytes in the message
            byte[] messageBytes = this.RegisterRead(0x00, numberOfBytes);

            string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
            Debug.WriteLine($"Received {messageBytes.Length} byte message {messageText}");
         }

         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
      }

The diagnostic output shows messages being received from one of my other devices.

The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Receive-Wait
RegIrqFlags 0X50
Receive-Message
Received 23 byte message  �LoRaIoT1N3WT 18.8,H 78
RegIrqFlags 0X50
Receive-Message
Received 23 byte message  �LoRaIoT1N3WT 18.7,H 79

The final step was to confirm the interrupt driven transmission of messages was working as expected.

   class Program
   {
      static void Main()
      {
#if TINYCLR_V2_SC20100DEV
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi3, SC20100.GpioPin.PA13, SC20100.GpioPin.PA14, SC20100.GpioPin.PE4);
#endif
#if TINYCLR_V2_FEZDUINO
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi6, SC20100.GpioPin.PB1, SC20100.GpioPin.PA15, SC20100.GpioPin.PA1); // Doesn't work
#endif
         int SendCount = 0;

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         // More power PA Boost
         rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

         // Interrupt on TxDone
         rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 TxDone

         while (true)
         {
            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0E, 0x00); // RegFifoTxBaseAddress 

            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

            string messageText = $"Hello LoRa {SendCount += 1}!";

            // load the message into the fifo
            byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
            rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

            // Set the length of the message in the fifo
            rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
            Debug.WriteLine($"Sending {messageBytes.Length} bytes message {messageText}");
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

            Thread.Sleep(10000);
         }
      }
   }


private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e)
      {
         if (e.Edge != GpioPinEdge.RisingEdge)
         {
            return;
         }

         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         Debug.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");

         if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
         {
            Debug.WriteLine("Transmit-Done");
         }

         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
      }

The diagnostic output shows messages being sent but after the first message (sometimes the second or third) there are no confirmations.

The thread ” (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 2!
Sending 13 bytes message Hello LoRa 3!
Sending 13 bytes message Hello LoRa 4!
Sending 13 bytes message Hello LoRa 5!
Sending 13 bytes message Hello LoRa 6!
Sending 13 bytes message Hello LoRa 7!
Sending 13 bytes message Hello LoRa 8!
Sending 13 bytes message Hello LoRa 9!
Sending 14 bytes message Hello LoRa 10!
Sending 14 bytes message Hello LoRa 11!
Sending 14 bytes message Hello LoRa 12!
Sending 14 bytes message Hello LoRa 13!
Sending 14 bytes message Hello LoRa 14!

It looks like something has been broken (possibly by RC1) in my implementation of interrupt driven transmission of messages.

nanoFramework LoRa library Part6

Transmit and Receive with Interrupts

For the final revision my nanoFramework SX127X Library test harness I checked interrupts were working for the interleaved transmission and reception of messages.

      private void InterruptGpioPin_ValueChanged(object sender, GpioPinValueChangedEventArgs e)
      {
         if (e.Edge != GpioPinEdge.RisingEdge)
         {
            return;
         }

         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         Console.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");

         if ((irqFlags & 0b01000000) == 0b01000000)  // RxDone 
         {
            Console.WriteLine("Receive-Message");
            byte currentFifoAddress = this.RegisterReadByte(0x10); // RegFifiRxCurrent
            this.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

            byte numberOfBytes = this.RegisterReadByte(0x13); // RegRxNbBytes

            // Allocate buffer for message
            byte[] messageBytes = this.RegisterRead(0X0, numberOfBytes);

            // Remove unprintable characters from messages
            for (int index = 0; index < messageBytes.Length; index++)
            {
               if ((messageBytes[index] < 0x20) || (messageBytes[index] > 0x7E))
               {
                  messageBytes[index] = 0x20;
               }
            }

            string messageText = UTF8Encoding.UTF8.GetString(messageBytes,0, messageBytes.Length);
            Console.WriteLine($"Received {messageBytes.Length} byte message {messageText}");
         }

         if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
         {
            this.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous
            Console.WriteLine("Transmit-Done");
         }

         this.RegisterWriteByte(0x40, 0b00000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
      }

…
class Program
{
      static void Main()
      {
         int SendCount = 0;
#if ST_STM32F429I_DISCOVERY
         int chipSelectPinNumber = PinNumber('C', 2);
         int resetPinNumber = PinNumber('C', 3);
         int interruptPinNumber = PinNumber('A', 4);
#endif
#if ESP32_WROOM_32_LORA_1_CHANNEL
         int chipSelectPinNumber = Gpio.IO16;
         int interruptPinNumber = Gpio.IO26;
#endif

         try
         {
#if ESP32_WROOM_32_LORA_1_CHANNEL
            Configuration.SetPinFunction(Gpio.IO12, DeviceFunction.SPI1_MISO);
            Configuration.SetPinFunction(Gpio.IO13, DeviceFunction.SPI1_MOSI);
            Configuration.SetPinFunction(Gpio.IO14, DeviceFunction.SPI1_CLOCK);
            Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SpiBusId, chipSelectPinNumber, interruptPinNumber);
#endif
#if ST_STM32F429I_DISCOVERY
            Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SpiBusId, chipSelectPinNumber, resetPinNumber, interruptPinNumber);
#endif
            Thread.Sleep(500);

            // Put device into LoRa + Standby mode
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

            // Set the frequency to 915MHz
            byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
            rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

            // More power PA Boost
            rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

            // Interrupt on TxDone
            rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 TxDone

            while (true)
            {
               // Set the Register Fifo address pointer
               rfm9XDevice.RegisterWriteByte(0x0E, 0x00); // RegFifoTxBaseAddress 

               // Set the Register Fifo address pointer
               rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

               string messageText = $"Hello LoRa {SendCount += 1}!";

               // load the message into the fifo
               byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
               rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

               // Set the length of the message in the fifo
               rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
               Console.WriteLine($"Sending {messageBytes.Length} bytes message {messageText}");
               rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

               Thread.Sleep(10000);
            }
         }
         catch (Exception ex)
         {
            Console.WriteLine(ex.Message);
         }
      }

The diagnostic output shows inbound and outbound messages

'nanoFramework.Tools.VS2019.Extension.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.NetNF\packages\nanoFramework.Hardware.Esp32.1.2.1-preview.10\lib\nanoFramework.Hardware.Esp32.dll', Symbols loaded.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 136
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 138
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 140
20:32:58.079 -> Sending HeLoRa World! 134
20:33:04.553 -> Message: Hello LoRa 1!
20:33:04.553 -> Length: 13
20:33:04.587 -> FirstChar: 72
20:33:04.587 -> RSSI: -52
20:33:04.587 -> Snr: 9.50
20:33:04.622 -> 
20:33:08.137 -> Sending HeLoRa World! 136
20:33:14.568 -> Message: Hello LoRa 2!
20:33:14.568 -> Length: 13
20:33:14.602 -> FirstChar: 72
20:33:14.602 -> RSSI: -53
20:33:14.602 -> Snr: 9.75
20:33:14.635 -> 
20:33:19.135 -> Sending HeLoRa World! 138
20:33:24.560 -> Message: Hello LoRa 3!
20:33:24.560 -> Length: 13
20:33:24.594 -> FirstChar: 72
20:33:24.594 -> RSSI: -52
20:33:24.594 -> Snr: 9.25
20:33:24.628 -> 

There did appear to be some oddness (leading to corrupted first message) with the RegOpMode setting(0b10000000 vs. 0b10000001) for my STM32F429 Discovery and Sparkfun LoRa Gateway 1 Channel ESP32.

I think it maybe due to the Discovery having the rest line connected but unlike the Sparkfun LoRa Gateway.

TinyCLR OS V2 LoRa library Part4

Transmit and Receive with Interrupts

For the final revision of the “nasty” test harness I ensured interrupts were working for the simultaneous transmission and reception of messages. It’s not quite simultaneous, the code sends a message every 10 seconds then goes back to receive continuous mode after each message has been sent.

private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e)
{
   if (e.Edge != GpioPinEdge.RisingEdge)
   {
      return;
   }

   byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
   Debug.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");

   if ((irqFlags & 0b01000000) == 0b01000000)  // RxDone 
   {
      Debug.WriteLine("Receive-Message");
      byte currentFifoAddress = this.RegisterReadByte(0x10); // RegFifiRxCurrent
      this.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

      byte numberOfBytes = this.RegisterReadByte(0x13); // RegRxNbBytes

      // Allocate buffer for message
      byte[] messageBytes = this.RegisterRead(0X0, numberOfBytes);

      string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
      Debug.WriteLine($"Received {messageBytes.Length} byte message {messageText}");
   }

  if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
  {
      this.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous
      Debug.WriteLine("Transmit-Done");
  }

   this.RegisterWriteByte(0x40, 0b00000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
   this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
}
…
class Program
{
   static void Main()
   {
      Rfm9XDevice rfm9XDevice = new Rfm9XDevice(SC20100.SpiBus.Spi3, SC20100.GpioPin.PA13, SC20100.GpioPin.PA14, SC20100.GpioPin.PE4);
      int sendCount = 0;

      // Put device into LoRa + Sleep mode
      rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

      // Set the frequency to 915MHz
      byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
      rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

      rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

      // More power PA Boost
      rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

      rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

      while (true)
      {
         rfm9XDevice.RegisterWriteByte(0x0E, 0x0); // RegFifoTxBaseAddress 

         // Set the Register Fifo address pointer
         rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

         string messageText = $"Hello LoRa {sendCount += 1}!";

         // load the message into the fifo
         byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
         rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

         // Set the length of the message in the fifo
         rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
         rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

         Debug.WriteLine($"Sending {messageBytes.Length} bytes message {messageText}");

         Thread.Sleep(10000);
      }
   }
}

The diagnostic output shows inbound and outbound messages

Found debugger!
Create TS.
Loading Deployment Assemblies.
Attaching deployed file.
Assembly: mscorlib (2.0.0.0)  Attaching deployed file.
Assembly: GHIElectronics.TinyCLR.Devices.Spi (2.0.0.0)  Attaching deployed file.
Assembly: GHIElectronics.TinyCLR.Native (2.0.0.0)  Attaching deployed file.
Assembly: GHIElectronics.TinyCLR.Devices.Gpio (2.0.0.0)  Attaching deployed file.
Assembly: ReceiveTransmitInterrupt (1.0.0.0)  Resolving.
The debugging target runtime is loading the application assemblies and starting execution.
Ready.
'GHIElectronics.TinyCLR.VisualStudio.ProjectSystem.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\ReceiveTransmitInterrupt\bin\Debug\pe\..\GHIElectronics.TinyCLR.Native.dll'
'GHIElectronics.TinyCLR.VisualStudio.ProjectSystem.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\ReceiveTransmitInterrupt\bin\Debug\pe\..\GHIElectronics.TinyCLR.Devices.Gpio.dll'
'GHIElectronics.TinyCLR.VisualStudio.ProjectSystem.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\ReceiveTransmitInterrupt\bin\Debug\pe\..\GHIElectronics.TinyCLR.Devices.Spi.dll'
'GHIElectronics.TinyCLR.VisualStudio.ProjectSystem.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\ReceiveTransmitInterrupt\bin\Debug\pe\..\ReceiveTransmitInterrupt.exe', Symbols loaded.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 59 byte message  �LoRaIoT1Maduino2at 77.9,ah 24,wsa 0,wsg 1,wd 12.38,r 0.00,
Sending 13 bytes message Hello LoRa 4!
RegIrqFlags 0X08
Transmit-Done
15:11:42.775 -> ync word
15:11:42.775 -> 0x0: 0x8A
15:11:42.775 -> 0x1: 0x81
15:11:42.798 -> 0x2: 0x1A
15:11:42.798 -> 0x3: 0xB
15:11:42.798 -> 0x4: 0x0
15:11:42.798 -> 0x5: 0x52
…
15:11:44.223 -> 0x7B: 0x0
15:11:44.223 -> 0x7C: 0x0
15:11:44.256 -> 0x7D: 0x0
15:11:44.256 -> 0x7E: 0x0
15:11:44.256 -> 0x7F: 0x0
15:11:44.291 -> LoRa init succeeded.
15:11:44.839 -> Sending HeLoRa World! 0
15:11:48.788 -> Message: ⸮LoRaIoT1Maduino2at 77.5,ah 25,wsa 1,wsg 5,wd 21.00,r 0.00,
15:11:48.856 -> Length: 59
15:11:48.856 -> FirstChar: 136
15:11:48.891 -> RSSI: -83
15:11:48.891 -> Snr: 9.50
15:11:48.891 -> 
15:11:49.234 -> Message: Hello LoRa 22!
15:11:49.234 -> Length: 14
15:11:49.268 -> FirstChar: 72
15:11:49.268 -> RSSI: -47
15:11:49.268 -> Snr: 9.75
15:11:49.303 -> 
15:11:55.815 -> Sending HeLoRa World! 2
15:11:59.219 -> Message: Hello LoRa 23!
15:11:59.219 -> Length: 14
15:11:59.254 -> FirstChar: 72
15:11:59.254 -> RSSI: -48
15:11:59.254 -> Snr: 9.75
15:11:59.288 -> 
15:12:06.597 -> Sending HeLoRa World! 4
15:12:09.218 -> Message: Hello LoRa 24!
15:12:09.218 -> Length: 14
15:12:09.253 -> FirstChar: 72
15:12:09.253 -> RSSI: -46
15:12:09.253 -> Snr: 9.25
15:12:09.287 -> 
15:12:16.919 -> Sending HeLoRa World! 6
15:12:19.240 -> Message: Hello LoRa 25!
15:12:19.240 -> Length: 14
15:12:19.275 -> FirstChar: 72
15:12:19.275 -> RSSI: -47
15:12:19.275 -> Snr: 9.75
15:12:19.309 -> 

The final step is back porting all the necessary changes to my Rfm9XDevice class then functionality and stress testing.

TinyCLR OS LoRa library Part8

Transmit and Receive with Interrupts

For the final iteration of the “nasty” test harness I got the interrupts working for the transmitting and receiving of messages. It’s not quite simultaneous, the code sends a message every 10 seconds then goes back to receive continuous mode after each message has been sent.

      public Rfm9XDevice(int chipSelectPin, int resetPin, int interruptPin)
      {
         var settings = new SpiConnectionSettings()
         {
            ChipSelectType = SpiChipSelectType.Gpio,
            ChipSelectLine = chipSelectPin,
            Mode = SpiMode.Mode0,
            ClockFrequency = 500000,
            DataBitLength = 8,
            ChipSelectActiveState = false,
         };

         SpiController spiCntroller = SpiController.FromName(FEZ.SpiBus.Spi1);

         rfm9XLoraModem = spiCntroller.GetDevice(settings);

         // Factory reset pin configuration
         GpioController gpioController = GpioController.GetDefault();
         GpioPin resetGpioPin = gpioController.OpenPin(resetPin);
         resetGpioPin.SetDriveMode(GpioPinDriveMode.Output);
         resetGpioPin.Write(GpioPinValue.Low);
         Thread.Sleep(10);
         resetGpioPin.Write(GpioPinValue.High);
         Thread.Sleep(10);

         // Interrupt pin for RX message & TX done notification 
         InterruptGpioPin = gpioController.OpenPin(interruptPin);
         resetGpioPin.SetDriveMode(GpioPinDriveMode.Input);

         InterruptGpioPin.ValueChanged += InterruptGpioPin_ValueChanged;
      }

      private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e)
      {
         if (e.Edge != GpioPinEdge.RisingEdge)
         {
            return;
         }

         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         Debug.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");

         if ((irqFlags & 0b01000000) == 0b01000000)  // RxDone 
         {
            Debug.WriteLine("Receive-Message");
            byte currentFifoAddress = this.RegisterReadByte(0x10); // RegFifiRxCurrent
            this.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

            byte numberOfBytes = this.RegisterReadByte(0x13); // RegRxNbBytes

            // Allocate buffer for message
            byte[] messageBytes = this.RegisterRead(0X0, numberOfBytes);

            string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
            Debug.WriteLine($"Received {messageBytes.Length} byte message {messageText}");
         }

         if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
         {
            this.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous
            Debug.WriteLine("Transmit-Done");
         }

         this.RegisterWriteByte(0x40, 0b00000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
      }

…

      public void RegisterDump()
      {
         Debug.WriteLine("Register dump");
         for (byte registerIndex = 0; registerIndex <= 0x42; registerIndex++)
         {
            byte registerValue = this.RegisterReadByte(registerIndex);

            Debug.WriteLine($"Register 0x{registerIndex:x2} - Value 0X{registerValue:x2}");
         }
      }
   }

   class Program
   {
      static void Main()
      {
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(FEZ.GpioPin.D10, FEZ.GpioPin.D9, FEZ.GpioPin.D2);
         int sendCount = 0;

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

         // More power PA Boost
         rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

         rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

         while (true)
         {
            rfm9XDevice.RegisterWriteByte(0x0E, 0x0); // RegFifoTxBaseAddress 

            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

            string messageText = $"Hello LoRa {sendCount += 1}!";

            // load the message into the fifo
            byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
            rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

            // Set the length of the message in the fifo
            rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
            rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

            Debug.WriteLine($"Sending {messageBytes.Length} bytes message {messageText}");

            Thread.Sleep(10000);
         }
      }
   }

The diagnostic output shows inbound and outbound messages (Arduino then Meadow diagnostics)

'GHIElectronics.TinyCLR.VisualStudio.ProjectSystem.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\ReceiveTransmitInterrupt\bin\Debug\pe\..\ReceiveTransmitInterrupt.exe', Symbols loaded.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 156
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 158
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 160
Sending 13 bytes message Hello LoRa 4!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 162
Sending 13 bytes message Hello LoRa 5!
RegIrqFlags 0X08
Transmit-Done
RegIrqFlags 0X50
Receive-Message
Received 17 byte message HeLoRa World! 164
Sending 13 bytes message Hello LoRa 6!
RegIrqFlags 0X08
Transmit-Done

20:55:09.280 -> Sending HeLoRa World! 152
20:55:25.179 -> Message: Hello LoRa 1!
20:55:25.179 -> RSSI: -44
20:55:25.212 -> Snr: 9.50
20:55:25.212 -> 
20:55:30.707 -> Sending HeLoRa World! 156
20:55:35.182 -> Message: Hello LoRa 2!
20:55:35.182 -> RSSI: -43
20:55:35.215 -> Snr: 9.50
20:55:35.215 -> 
20:55:41.358 -> Sending HeLoRa World! 158
20:55:45.181 -> Message: Hello LoRa 3!
20:55:45.181 -> RSSI: -44
20:55:45.214 -> Snr: 9.50
20:55:45.214 -> 
20:55:52.032 -> Sending HeLoRa World! 160
20:55:55.190 -> Message: Hello LoRa 4!
20:55:55.190 -> RSSI: -44
20:55:55.258 -> Snr: 9.50
20:55:55.258 -> 
20:56:02.451 -> Sending HeLoRa World! 162
20:56:05.206 -> Message: Hello LoRa 5!
20:56:05.206 -> RSSI: -41
20:56:05.241 -> Snr: 9.00
20:56:05.241 -> 
20:56:12.685 -> Sending HeLoRa World! 164
20:56:15.226 -> Message: Hello LoRa 6!
20:56:15.226 -> RSSI: -41
20:56:15.261 -> Snr: 9.25
20:56:15.261 -> 
20:56:22.817 -> Sending HeLoRa World! 166
20:56:25.248 -> Message: Hello LoRa 7!
20:56:25.248 -> RSSI: -36
20:56:25.283 -> Snr: 10.00
20:56:25.283 -> 

Next step is some refactoring to extract the register access code and merging with my Windows 10 IoT Core RMF9X library code base.

TinyCLR OS LoRa library Part7

Transmit Interrupt

Starting with the TransmitBasic sample application I modified the code so that a hardware interrupt (specified in RegDioMapping1) was generated on TxDone (FIFO Payload Transmission completed).

The application inserts a message into the RFM95 transmit FIFO every 10 seconds with confirmation of transmission displayed shortly afterwards

      public Rfm9XDevice(int chipSelectPin, int resetPin, int interruptPin)
      {
         var settings = new SpiConnectionSettings()
         {
            ChipSelectType = SpiChipSelectType.Gpio,
            ChipSelectLine = chipSelectPin,
            Mode = SpiMode.Mode0,
            ClockFrequency = 500000,
            DataBitLength = 8,
            ChipSelectActiveState = false,
         };

         SpiController spiCntroller = SpiController.FromName(FEZ.SpiBus.Spi1);

         rfm9XLoraModem = spiCntroller.GetDevice(settings);

         // Factory reset pin configuration
         GpioController gpioController = GpioController.GetDefault();
         GpioPin resetGpioPin = gpioController.OpenPin(resetPin);
         resetGpioPin.SetDriveMode(GpioPinDriveMode.Output);
         resetGpioPin.Write(GpioPinValue.Low);
         Thread.Sleep(10);
         resetGpioPin.Write(GpioPinValue.High);
         Thread.Sleep(10);

         // Interrupt pin for RX message & TX done notification 
         InterruptGpioPin = gpioController.OpenPin(interruptPin);
         resetGpioPin.SetDriveMode(GpioPinDriveMode.Input);

         InterruptGpioPin.ValueChanged += InterruptGpioPin_ValueChanged;
      }

      private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e)
      {
         if (e.Edge != GpioPinEdge.RisingEdge)
         {
            return;
         }

         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         Debug.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");

         if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
         {
            Debug.WriteLine("Transmit-Done");
         }

         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
      }
…
   class Program
   {
      static void Main()
      {
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(FEZ.GpioPin.D10, FEZ.GpioPin.D9, FEZ.GpioPin.D2);
         int SendCount = 0;

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         // More power PA Boost
         rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

         // Interrupt on TxDone
         rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 TxDone

         while (true)
         {
            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0E, 0x00); // RegFifoTxBaseAddress 

            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

            string messageText = $"Hello LoRa {SendCount += 1}!";

            // load the message into the fifo
            byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
            rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

            // Set the length of the message in the fifo
            rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
            Debug.WriteLine($"Sending {messageBytes.Length} bytes message {messageText}");
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

            Thread.Sleep(10000);
         }
      }
   }

The output in the debug window

'GHIElectronics.TinyCLR.VisualStudio.ProjectSystem.dll' (Managed): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\TransmitInterrupt\bin\Debug\pe\..\TransmitInterrupt.exe', Symbols loaded.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Sending 13 bytes message Hello LoRa 1!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 2!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 3!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 4!
RegIrqFlags 0X08
Transmit-Done
Sending 13 bytes message Hello LoRa 5!
RegIrqFlags 0X08
Transmit-Done

On the Arduino test client the serial monitor displayed

19:39:55.595 -> LoRa init succeeded.
19:39:56.157 -> Sending HeLoRa World! 0
19:39:58.742 -> Message: Hello LoRa 5!
19:39:58.742 -> RSSI: -36
19:39:58.789 -> Snr: 9.50
19:39:58.789 -> 
19:40:07.151 -> Sending HeLoRa World! 2
19:40:11.920 -> Message: Hello LoRa 1!
19:40:11.920 -> RSSI: -41
19:40:11.967 -> Snr: 9.75
19:40:11.967 -> 
19:40:17.924 -> Sending HeLoRa World! 4
19:40:21.905 -> Message: Hello LoRa 2!
19:40:21.905 -> RSSI: -41
19:40:21.952 -> Snr: 9.50
19:40:21.952 -> 
19:40:28.248 -> Sending HeLoRa World! 6
19:40:31.928 -> Message: Hello LoRa 3!
19:40:31.928 -> RSSI: -36
19:40:31.975 -> Snr: 9.50
19:40:31.975 -> 
19:40:38.803 -> Sending HeLoRa World! 8
19:40:41.928 -> Message: Hello LoRa 4!
19:40:41.928 -> RSSI: -34
19:40:41.975 -> Snr: 9.25
19:40:41.975 -> 

Now that I’m confident my hardware is all working as expected the next step will be building a client which has a receive and transmit interrupt handler.

TinyCLR OS LoRa library Part6

Receive Interrupt

This proof of concept (PoC) was to confirm I could configure the Semtech 127X then handle the received messages using a TinyCLR GpioPinValueChangedEventHandler.

   public sealed class Rfm9XDevice
   {
      private SpiDevice rfm9XLoraModem;
      private GpioPin InterruptGpioPin = null;
      private const byte RegisterAddressReadMask = 0X7f;
      private const byte RegisterAddressWriteMask = 0x80;

      public Rfm9XDevice(int chipSelectPin, int resetPin, int interruptPin)
      {
         var settings = new SpiConnectionSettings()
         {
            ChipSelectType = SpiChipSelectType.Gpio,
            ChipSelectLine = chipSelectPin,
            Mode = SpiMode.Mode0,
            ClockFrequency = 500000,
            DataBitLength = 8,
            ChipSelectActiveState = false,
         };

         SpiController spiCntroller = SpiController.FromName(FEZ.SpiBus.Spi1);

         rfm9XLoraModem = spiCntroller.GetDevice(settings);

         // Factory reset pin configuration
         GpioController gpioController = GpioController.GetDefault();
         GpioPin resetGpioPin = gpioController.OpenPin(resetPin);
         resetGpioPin.SetDriveMode(GpioPinDriveMode.Output);
         resetGpioPin.Write(GpioPinValue.Low);
         Thread.Sleep(10);
         resetGpioPin.Write(GpioPinValue.High);
         Thread.Sleep(10);

         // Interrupt pin for RX message & TX done notification 
         InterruptGpioPin = gpioController.OpenPin(interruptPin);
         resetGpioPin.SetDriveMode(GpioPinDriveMode.Input);

         InterruptGpioPin.ValueChanged += InterruptGpioPin_ValueChanged;
      }

      private void InterruptGpioPin_ValueChanged(GpioPin sender, GpioPinValueChangedEventArgs e)
      {
         if (e.Edge != GpioPinEdge.RisingEdge)
         {
            return;
         }

         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         Debug.WriteLine($"RegIrqFlags 0X{irqFlags:x2}");
         if ((irqFlags & 0b01000000) == 0b01000000)  // RxDone 
         {
            Debug.WriteLine("Receive-Message");
            byte currentFifoAddress = this.RegisterReadByte(0x10); // RegFifiRxCurrent
            this.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

            byte numberOfBytes = this.RegisterReadByte(0x13); // RegRxNbBytes

            // Get number of bytes in the message
            byte[] messageBytes = this.RegisterRead(0x00, numberOfBytes);

            string messageText = UTF8Encoding.UTF8.GetString(messageBytes);
            Debug.WriteLine($"Received {messageBytes.Length} byte message {messageText}");
         }

         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
      }
...
   class Program
   {
      static void Main()
      {
         Rfm9XDevice rfm9XDevice = new Rfm9XDevice(FEZ.GpioPin.D10, FEZ.GpioPin.D9, FEZ.GpioPin.D2);

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

         rfm9XDevice.RegisterWriteByte(0x40, 0b00000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady

         rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

         rfm9XDevice.RegisterDump();

         Debug.WriteLine("Receive-Wait");
         Thread.Sleep(Timeout.Infinite);
      }
   }

The output in the output debug window looked like this

'C:\Users\BrynLewis\source\repos\RFM9X.TinyCLR\ReceiveInterrupt\bin\Debug\pe\..\ReceiveInterrupt.exe', Symbols loaded.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
Register dump
Register 0x00 - Value 0X88
Register 0x01 - Value 0X85
Register 0x02 - Value 0X1a
..
Register 0x41 - Value 0X00
Register 0x42 - Value 0X12
Receive-Wait
RegIrqFlags 0X50
Receive-Message
Received 15 byte message HeLoRa World! 0
RegIrqFlags 0X50
Receive-Message
Received 15 byte message HeLoRa World! 2
RegIrqFlags 0X50
Receive-Message
Received 15 byte message HeLoRa World! 4
RegIrqFlags 0X50
Receive-Message
Received 15 byte message HeLoRa World! 6
RegIrqFlags 0X50
Receive-Message
Received 15 byte message HeLoRa World! 8
RegIrqFlags 0X50
Receive-Message
Received 16 byte message HeLoRa World! 10
RegIrqFlags 0X50
Receive-Message
Received 16 byte message HeLoRa World! 12

Next steps will be wiring up the transmit done interrupt, then building a full featured client based on my Windows 10 IoT Core library.

.Net Meadow RFM95/96/97/98 LoRa library Part8

Transmit and Receive with Interrupts

For the final iteration of the “nasty” test harness I got the interrupts working for the transmitting and receiving of messages. It’s not quite simultaneous, the code sends a message every 10 seconds then goes back to receive continuous mode after each message has been sent.

      public Rfm9XDevice(IIODevice device, ISpiBus spiBus, IPin chipSelectPin, IPin resetPin, IPin interruptPin)
      {
         // Chip select pin configuration
         ChipSelectGpioPin = device.CreateDigitalOutputPort(chipSelectPin, initialState: true);
         if (ChipSelectGpioPin == null)
         {
            Console.WriteLine("ChipSelectGpioPin == null");
         }

         // Factory reset pin configuration
         IDigitalOutputPort resetGpioPin = device.CreateDigitalOutputPort(resetPin);
         if (resetGpioPin == null)
         {
            Console.WriteLine("resetGpioPin == null");
         }
         resetGpioPin.State = false;
         Task.Delay(10);
         resetGpioPin.State = true;
         Task.Delay(10);

         // Interrupt pin for RX message & TX done notification 
         InterruptGpioPin = device.CreateDigitalInputPort(interruptPin, InterruptMode.EdgeRising);
         InterruptGpioPin.Changed += InterruptGpioPin_ValueChanged;

         Rfm9XLoraModem = new SpiPeripheral(spiBus, ChipSelectGpioPin);
         if (Rfm9XLoraModem == null)
         {
            Console.WriteLine("Rfm9XLoraModem == null");
         }
      }

      private void InterruptGpioPin_ValueChanged(object sender, DigitalInputPortEventArgs args)
      {
         byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
         byte numberOfBytes = 0;
         string messageText = "";
         bool transmitDone = false;

         //Console.WriteLine(string.Format("RegIrqFlags:{0}", Convert.ToString(irqFlags, 2).PadLeft(8, '0')));
         if ((irqFlags & 0b01000000) == 0b01000000)
         {
            //Console.WriteLine("Receive-Message");
            byte currentFifoAddress = this.RegisterReadByte(0x10); // RegFifiRxCurrent
            this.RegisterWriteByte(0x0d, currentFifoAddress); // RegFifoAddrPtr

            numberOfBytes = this.RegisterReadByte(0x13); // RegRxNbBytes
            byte[] messageBytes = this.RegisterRead(0x00, numberOfBytes); // RegFifo
            messageText = UTF8Encoding.UTF8.GetString(messageBytes);
         }

         if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
         {
            this.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous
            transmitDone = true;
         }

         this.RegisterWriteByte(0x40, 0b00000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
         this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags
         if (numberOfBytes > 0)
         {
            Console.WriteLine("Received {0} byte message {1}", numberOfBytes, messageText);
         }
         if(transmitDone)
         {
            Console.WriteLine("Transmit-Done");
         }
      }
...
   public class MeadowApp : App<F7Micro, MeadowApp>
   {
      private Rfm9XDevice rfm9XDevice;
      private byte NessageCount = Byte.MaxValue;

      public MeadowApp()
      {
         ISpiBus spiBus = Device.CreateSpiBus(500);
         if (spiBus == null)
         {
            Console.WriteLine("spiBus == null");
         }

         rfm9XDevice = new Rfm9XDevice(Device, spiBus, Device.Pins.D09, Device.Pins.D11, Device.Pins.D10);

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         rfm9XDevice.RegisterWriteByte(0x0F, 0x0); // RegFifoRxBaseAddress 

         rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

         rfm9XDevice.RegisterWriteByte(0x01, 0b10000101); // RegOpMode set LoRa & RxContinuous

         while (true)
         {
            rfm9XDevice.RegisterWriteByte(0x0E, 0x0); // RegFifoTxBaseAddress 

            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

            string messageText = "W10 IoT Core LoRa! " + NessageCount.ToString();
            NessageCount -= 1;

            // load the message into the fifo
            byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
            rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

            // Set the length of the message in the fifo
            rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
            Console.WriteLine("Sending {0} bytes message {1}", messageBytes.Length, messageText);
            rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 RxReady & TxReady
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

            Debug.WriteLine("Sending {0} bytes message {1}", messageBytes.Length, messageText);

            Task.Delay(10000).Wait();
         }
      }

The diagnostic output shows inbound and outbound messages (Arduino then Meadow diagnostics)

21:15:56.070 -> 0x1: 0x81
21:15:56.070 -> 0x2: 0x1A
…
21:15:57.527 -> 0x7E: 0x0
21:15:57.527 -> 0x7F: 0x0
21:15:57.527 -> LoRa init succeeded.
21:15:58.101 -> Sending HeLoRa World! 0
21:16:06.958 -> Message: W10 IoT Core LoRa! 254
21:16:06.991 -> RSSI: -60
21:16:06.991 -> Snr: 9.50
21:16:06.991 ->
21:16:09.062 -> Sending HeLoRa World! 2
21:16:17.184 -> Message: W10 IoT Core LoRa! 253
21:16:17.218 -> RSSI: -61
21:16:17.218 -> Snr: 9.75
21:16:17.218 ->
21:16:19.876 -> Sending HeLoRa World! 4
21:16:21.946 -> Message: ⸮LoRaIoT1Maduino2at 65.3,ah 70,wsa 6,wsg 12,wd 167.25,r 0.00,
21:16:22.014 -> RSSI: -76
21:16:22.014 -> Snr: 9.50
21:16:22.014 ->
21:16:27.406 -> Message: W10 IoT Core LoRa! 252
21:16:27.429 -> RSSI: -60
21:16:27.429 -> Snr: 9.50
21:16:27.429 ->
21:16:30.153 -> Sending HeLoRa World! 6
'App.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_64\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. 
'App.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.Meadow\ReceiveTransmitInterrupt\bin\Debug\net472\App.exe'. Symbols loaded.
'App.exe' (CLR v4.0.30319: App.exe): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.Meadow\ReceiveTransmitInterrupt\bin\Debug\net472\Meadow.dll'. 
The program '[42104] App.exe: Program Trace' has exited with code 0 (0x0).
The program '[42104] App.exe' has exited with code 0 (0x0).
 .
 .
 DirectRegisterAccess = True
 .
 .
 Sending 22 bytes message W10 IoT Core LoRa! 255
 Transmit-Done
 Received 15 byte message HeLoRa World! 0
 Sending 22 bytes message W10 IoT Core LoRa! 254
 Transmit-Done
 Received 15 byte message HeLoRa World! 2
 Sending 22 bytes message W10 IoT Core LoRa! 253
 Transmit-Done
 Received 15 byte message HeLoRa World! 4
 Received 61 byte message ???LoRaIoT1Maduino2at 65.3,ah 70,wsa 6,wsg 12,wd 167.25,r 0.00,
 Sending 22 bytes message W10 IoT Core LoRa! 252
 Transmit-Done
 Received 15 byte message HeLoRa World! 6
 Sending 22 bytes message W10 IoT Core LoRa! 251
 Transmit-Done
 Received 15 byte message HeLoRa World! 8
 Sending 22 bytes message W10 IoT Core LoRa! 250
 Transmit-Done
 Received 16 byte message HeLoRa World! 10
 Sending 22 bytes message W10 IoT Core LoRa! 249
 Transmit-Done
 Received 16 byte message HeLoRa World! 12
 Received 40 byte message ???LoRaIoT1#)#???c???h 55,t 24.9,s 3,v 4.01
 Sending 22 bytes message W10 IoT Core LoRa! 248
 Transmit-Done
 Received 16 byte message HeLoRa World! 14
 Sending 22 bytes message W10 IoT Core LoRa! 247
 Transmit-Done
 Received 16 byte message ???LoRaIoT1Maduino
 Sending 22 bytes message W10 IoT Core LoRa! 246
 Transmit-Done
 Received 16 byte message HeLoRa World! 18
 Sending 22 bytes message W10 IoT Core LoRa! 245
 Transmit-Done
 Received 16 byte message HeLoRa World! 20
 Sending 22 bytes message W10 IoT Core LoRa! 244
 Transmit-Done
 Received 16 byte message HeLoRa World! 22
 Sending 22 bytes message W10 IoT Core LoRa! 243
 Transmit-Done
 Received 16 byte message HeLoRa World! 24
 Sending 22 bytes message W10 IoT Core LoRa! 242
 Transmit-Done

The RegIrqFlags 01011000 indicates the RxDone, ValidHeader, and TxDone flags were set which was what I was expecting. Note the interference, the 46 byte packet

Next step is some refactoring to extract the register access code and merging with my Windows 10 IoT Core RMF9X library code base.

.Net Meadow RFM95/96/97/98 LoRa library Part7

Transmit Interrupt

Starting with the TransmitBasic sample application I modified the code so that a hardware interrupt (specified in RegDioMapping1) was generated on TxDone (FIFO Payload Transmission completed).

The application inserts a message into the RFM95 transmit FIFO every 10 seconds with confirmation of transmission displayed shortly afterwards

      public Rfm9XDevice(IIODevice device, ISpiBus spiBus, IPin chipSelectPin, IPin resetPin, IPin interruptPin)
      {
         // Chip select pin configuration
         ChipSelectGpioPin = device.CreateDigitalOutputPort(chipSelectPin, initialState: true);
         if (ChipSelectGpioPin == null)
         {
            Console.WriteLine("ChipSelectGpioPin == null");
         }

         // Factory reset pin configuration
         IDigitalOutputPort resetGpioPin = device.CreateDigitalOutputPort(resetPin);
         if (resetGpioPin == null)
         {
            Console.WriteLine("resetGpioPin == null");
         }
         resetGpioPin.State = false;
         Task.Delay(10);
         resetGpioPin.State = true;
         Task.Delay(10);

         // Interrupt pin for RX message & TX done notification 
         InterruptGpioPin = device.CreateDigitalInputPort(interruptPin, InterruptMode.EdgeRising);
         InterruptGpioPin.Changed += InterruptGpioPin_ValueChanged;

         Rfm9XLoraModem = new SpiPeripheral(spiBus, ChipSelectGpioPin);
         if (Rfm9XLoraModem == null)
         {
            Console.WriteLine("Rfm9XLoraModem == null");
         }
      }

      private void InterruptGpioPin_ValueChanged(object sender, DigitalInputPortEventArgs args)
      {
        byte irqFlags = this.RegisterReadByte(0x12); // RegIrqFlags
        this.RegisterWriteByte(0x12, 0xff);// Clear RegIrqFlags

        //Console.WriteLine(string.Format("RegIrqFlags:{0}", Convert.ToString(irqFlags, 2).PadLeft(8, '0')));
         if ((irqFlags & 0b00001000) == 0b00001000)  // TxDone
         {
            Console.WriteLine("Transmit-Done");
         }
      }
…
   public class MeadowApp : App<F7Micro, MeadowApp>
   {
      private Rfm9XDevice rfm9XDevice;

      public MeadowApp()
      {
         ISpiBus spiBus = Device.CreateSpiBus(500);
         if (spiBus == null)
         {
            Console.WriteLine("spiBus == null");
         }

         rfm9XDevice = new Rfm9XDevice(Device, spiBus, Device.Pins.D09, Device.Pins.D11, Device.Pins.D10);

         // Put device into LoRa + Sleep mode
         rfm9XDevice.RegisterWriteByte(0x01, 0b10000000); // RegOpMode 

         // Set the frequency to 915MHz
         byte[] frequencyWriteBytes = { 0xE4, 0xC0, 0x00 }; // RegFrMsb, RegFrMid, RegFrLsb
         rfm9XDevice.RegisterWrite(0x06, frequencyWriteBytes);

         // More power PA Boost
         rfm9XDevice.RegisterWriteByte(0x09, 0b10000000); // RegPaConfig

         // Interrupt on TxDone
         rfm9XDevice.RegisterWriteByte(0x40, 0b01000000); // RegDioMapping1 0b00000000 DI0 TxDone

         while (true)
         {
            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0E, 0x00); // RegFifoTxBaseAddress 

            // Set the Register Fifo address pointer
            rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr 

            string messageText = "Hello LoRa!";

            // load the message into the fifo
            byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
            rfm9XDevice.RegisterWrite(0x0, messageBytes); // RegFifo 

            // Set the length of the message in the fifo
            rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
            Console.WriteLine("Sending {0} bytes message {1}", messageBytes.Length, messageText);
            rfm9XDevice.RegisterWriteByte(0x01, 0b10000011); // RegOpMode 

            Task.Delay(10000).Wait();
         }
      }
   }

The output in the debug window

'App.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\WINDOWS\Microsoft.Net\assembly\GAC_64\mscorlib\v4.0_4.0.0.0__b77a5c561934e089\mscorlib.dll'. 
'App.exe' (CLR v4.0.30319: DefaultDomain): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.Meadow\TransmitInterrupt\bin\Debug\net472\App.exe'. Symbols loaded.
'App.exe' (CLR v4.0.30319: App.exe): Loaded 'C:\Users\BrynLewis\source\repos\RFM9X.Meadow\TransmitInterrupt\bin\Debug\net472\Meadow.dll'. 
The program '[11164] App.exe: Program Trace' has exited with code 0 (0x0).
The program '[11164] App.exe' has exited with code 0 (0x0).
.
.
DirectRegisterAccess = True
.
.
Sending 11 bytes message Hello LoRa!
Transmit-Done
Sending 11 bytes message Hello LoRa!
Transmit-Done
Sending 11 bytes message Hello LoRa!
Transmit-Done

On the Arduino test client the serial monitor displayed

13:02:09.098 -> Sending HeLoRa World! 4
13:02:19.130 -> Message: ⸮LoRaIoT1Maduino2at 79.7,ah 39,wsa 6,wsg 13,wd 28.13,r 0.00,
13:02:19.177 -> RSSI: -72
13:02:19.177 -> Snr: 9.25
13:02:19.177 -> 
13:02:19.431 -> Sending HeLoRa World! 6
13:02:29.994 -> Sending HeLoRa World! 8
13:02:32.000 -> Message: Hello LoRa!
13:02:32.000 -> RSSI: -46
13:02:32.047 -> Snr: 9.50
13:02:32.047 -> 
13:02:40.750 -> Sending HeLoRa World! 10
13:02:42.260 -> Message: Hello LoRa!
13:02:42.260 -> RSSI: -45
13:02:42.314 -> Snr: 9.50
13:02:42.314 -> 
13:02:51.286 -> Sending HeLoRa World! 12
13:02:52.541 -> Message: Hello LoRa!
13:02:52.541 -> RSSI: -45
13:02:52.541 -> Snr: 9.75
13:02:52.541 -> 
13:03:02.112 -> Sending HeLoRa World! 14
13:03:02.745 -> Message: Hello LoRa!
13:03:02.745 -> RSSI: -45
13:03:02.792 -> Snr: 9.50
13:03:02.792 -> 

Now that I’m confident my hardware is all working the next step will be building a full featured client based on my Windows 10 IoT Core library.