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.