Receive and Transmit Interrupts
For the second to last development iteration of my RFM9X LoRa NetMF library client I have got the interrupt handler working for transmitting and receiving messages. My code sends a message every 10 seconds then goes back to waiting in receive mode .
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namespace devMobile.IoT.NetMF.Rfm9X.ReceiveTransmitInterrupt
{
using System;
using System.Text;
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
public sealed class Rfm9XDevice
{
private const byte RegisterAddressReadMask = 0X7f;
private const byte RegisterAddressWriteMask = 0x80;
private SPI Rfm9XLoraModem = null;
private OutputPort ResetGpioPin = null;
private InterruptPort InterruptPin = null;
public Rfm9XDevice(Cpu.Pin chipSelect, Cpu.Pin resetPin, Cpu.Pin interruptPin)
{
// Factory reset pin configuration
ResetGpioPin = new OutputPort(Pins.GPIO_PIN_D9, true);
ResetGpioPin.Write(false);
Thread.Sleep(10);
ResetGpioPin.Write(true);
Thread.Sleep(10);
this.Rfm9XLoraModem = new SPI(new SPI.Configuration(chipSelect, false, 0, 0, false, false, 2000, SPI.SPI_module.SPI1));
InterruptPin = new InterruptPort(interruptPin, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeHigh);
InterruptPin.OnInterrupt += InterruptPin_OnInterrupt;
Thread.Sleep(100);
}
public Rfm9XDevice(Cpu.Pin chipSelect, Cpu.Pin reset)
{
// Factory reset pin configuration
ResetGpioPin = new OutputPort(Pins.GPIO_PIN_D9, true);
ResetGpioPin.Write(false);
Thread.Sleep(10);
ResetGpioPin.Write(true);
Thread.Sleep(10);
this.Rfm9XLoraModem = new SPI(new SPI.Configuration(chipSelect, false, 0, 0, false, false, 2000, SPI.SPI_module.SPI1));
Thread.Sleep(100);
}
public Byte RegisterReadByte(byte registerAddress)
{
byte[] writeBuffer = new byte[] { registerAddress };
byte[] readBuffer = new byte[1];
Debug.Assert(Rfm9XLoraModem != null);
Rfm9XLoraModem.WriteRead(writeBuffer, readBuffer, 1);
return readBuffer[0];
}
public ushort RegisterReadWord(byte address)
{
byte[] writeBuffer = new byte[] { address &= RegisterAddressReadMask };
byte[] readBuffer = new byte[2];
Debug.Assert(Rfm9XLoraModem != null);
readBuffer[0] = RegisterReadByte(address);
readBuffer[1] = RegisterReadByte(address += 1);
return (ushort)(readBuffer[1] + (readBuffer[0] << 8));
}
public byte[] RegisterRead(byte address, int length)
{
byte[] writeBuffer = new byte[] { address &= RegisterAddressReadMask };
byte[] readBuffer = new byte[length];
Debug.Assert(Rfm9XLoraModem != null);
for (byte index = 0; index < length; index++)
{
readBuffer[index] = RegisterReadByte(address += 1);
}
return readBuffer;
}
public void RegisterWriteByte(byte address, byte value)
{
byte[] writeBuffer = new byte[] { address |= RegisterAddressWriteMask, value };
Debug.Assert(Rfm9XLoraModem != null);
Rfm9XLoraModem.Write(writeBuffer);
}
public void RegisterWriteWord(byte address, ushort value)
{
byte[] valueBytes = BitConverter.GetBytes(value);
byte[] writeBuffer = new byte[] { address |= RegisterAddressWriteMask, valueBytes[0], valueBytes[1] };
Debug.Assert(Rfm9XLoraModem != null);
Rfm9XLoraModem.Write(writeBuffer);
}
public void RegisterWrite(byte address, byte[] bytes)
{
byte[] writeBuffer = new byte[1 + bytes.Length];
Debug.Assert(Rfm9XLoraModem != null);
Array.Copy(bytes, 0, writeBuffer, 1, bytes.Length);
writeBuffer[0] = address |= RegisterAddressWriteMask;
Rfm9XLoraModem.Write(writeBuffer);
}
public void RegisterDump()
{
Debug.Print("---Registers 0x00 thru 0x42---");
for (byte registerIndex = 0; registerIndex 4];
// Mask off the upper 4 bits to get the rest of it.
hexString += hexChars[singlebyte & 0x0F];
return hexString;
}
private static string WordToHexString(ushort singleword)
{
string hexString = string.Empty;
byte[] bytes = BitConverter.GetBytes(singleword);
hexString += ByteToHexString(bytes[1]);
hexString += ByteToHexString(bytes[0]);
return hexString;
}
public class Program
{
public static void Main()
{
Rfm9XDevice rfm9XDevice = new Rfm9XDevice(Pins.GPIO_PIN_D10, Pins.GPIO_PIN_D9, Pins.GPIO_PIN_D2);
byte MessageCount = Byte.MinValue;
// Put device into LoRa + Sleep mode
rfm9XDevice.RegisterWriteByte(0x01, 0x80); // 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, 0x80); // RegPaConfig
//rfm9XDevice.RegisterWriteByte(0x40, 0x0);
rfm9XDevice.RegisterWriteByte(0x01, 0x85); // 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 NetMF LoRa! " + MessageCount.ToString() ;
MessageCount += 1;
// load the message into the fifo
byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
foreach (byte b in messageBytes)
{
rfm9XDevice.RegisterWriteByte(0x0, b); // RegFifo
}
// Set the length of the message in the fifo
rfm9XDevice.RegisterWriteByte(0x22, (byte)messageBytes.Length); // RegPayloadLength
rfm9XDevice.RegisterWriteByte(0x40, 0x40); // RegDioMapping1
/// Set the mode to LoRa + Transmit
rfm9XDevice.RegisterWriteByte(0x01, 0x83); // RegOpMode
Debug.Print("Sending " + messageBytes.Length + " bytes message " + messageText);
Thread.Sleep(10000);
}
}
}
}
}
On the Netduino3 device messages were being sent and received
The thread '' (0x2) has exited with code 0 (0x0). Sending 19 bytes message Hello NetMF LoRa! 0 RegIrqFlags 08 Transmit-Done Sending 19 bytes message Hello NetMF LoRa! 1 RegIrqFlags 08 Transmit-Done Sending 19 bytes message Hello NetMF LoRa! 2 RegIrqFlags 08 Transmit-Done Sending 19 bytes message Hello NetMF LoRa! 3 RegIrqFlags 08 Transmit-Done RegIrqFlags 50 Receive-Message Received 15 byte message HeLoRa World! 0 RegIrqFlags 50 Receive-Message Received 15 byte message HeLoRa World! 2 Sending 19 bytes message Hello NetMF LoRa! 4 RegIrqFlags 08 Transmit-Done RegIrqFlags 50 Receive-Message
On my Windows 10 Core device I could see messages arriving
RegIrqFlags 01010000 RX-Done Received 19 byte message Hello NetMF LoRa! 1 The thread 0x168 has exited with code 0 (0x0). RegIrqFlags 01010000 RX-Done Received 19 byte message Hello NetMF LoRa! 2 The thread 0x8 has exited with code 0 (0x0). RegIrqFlags 01010000 RX-Done
This library is going to be quite a bit smaller/lighter than my Windows 10 IoT Core one so the next so next step event handlers and refactoring.
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