Transmit Interrupt
Starting with the TransmitBasic sample application I modified the code so that a hardware interrupt (specified by SX1276 RegDioMapping1) was generated on TxDone (FIFO Payload Transmission completed).
The application inserts a message into the SX1276 transmit FIFO every 10 seconds with confirmation of transmission displayed shortly afterwards
//--------------------------------------------------------------------------------- // Copyright (c) August 2018, devMobile Software // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // //--------------------------------------------------------------------------------- namespace devMobile.IoT.NetMF.Rfm9X.TransmitInterrupt { 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 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 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; } void InterruptPin_OnInterrupt(uint data1, uint data2, DateTime time) { byte IrqFlags = this.RegisterReadByte(0x12); // RegIrqFlags Debug.Print("RegIrqFlags " + ByteToHexString(IrqFlags)); if ((IrqFlags & 0x08) == 0x08) // TxDone { Debug.Print("Transmit-Done"); } this.RegisterWriteByte(0x12, 0xff);// RegIrqFlags } 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; while (true) { // 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); // More power - PA_BOOST rfm9XDevice.RegisterWriteByte(0x09, 0x80); // RegPaConfig // Interrupt on TxDone rfm9XDevice.RegisterWriteByte(0x40, 0x40); // RegDioMapping1 0b00000000 DI0 TxDone while (true) { rfm9XDevice.RegisterWriteByte(0x0E, 0x0); // RegFifoTxBaseAddress // Set the Register Fifo address pointer rfm9XDevice.RegisterWriteByte(0x0D, 0x0); // RegFifoAddrPtr string messageText = "Hello NetMF LoRa! "; if (MessageCount != 0) { messageText += "-" + MessageCount.ToString(); } else { messageText += 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 Debug.Print("Sending " + messageBytes.Length + " bytes message " + messageText); /// Set the mode to LoRa + Transmit rfm9XDevice.RegisterWriteByte(0x01, 0x83); // RegOpMode Thread.Sleep(10000); } } } } } }
Unlike the Windows 10 IoT core version I can configure the interrupt to only trigger on the leading edge.
InterruptPin = new InterruptPort(interruptPin, false, Port.ResistorMode.Disabled, Port.InterruptMode.InterruptEdgeHigh);
In the Debug output window of VS2K12 I could see
The thread '' (0x2) has exited with code 0 (0x0). Sending 19 bytes message Hello NetMF LoRa! 0 RegIrqFlags 08 Transmit-Done Sending 20 bytes message Hello NetMF LoRa! -1 RegIrqFlags 08 Transmit-Done Sending 20 bytes message Hello NetMF LoRa! -2 RegIrqFlags 08 Transmit-Done
On my Arduino device the message arrived
LoRa Receiver Callback Received packet 'Hello NetMF LoRa! 0' with RSSI -29 Received packet 'Hello NetMF LoRa! -1' with RSSI -29 Received packet 'Hello NetMF LoRa! -2' with RSSI -29 Received packet 'Hello NetMF LoRa! -3' with RSSI -29 Received packet 'Hello NetMF LoRa! -4' with RSSI -29
Next step interrupts for processing inbound messages