After a month of posts the source code of V0.9 of my RFM9X/SX127X library is on GitHub. I included all of the source for my test harness and proof of concept(PoC) applications so other people can follow along with “my learning experience”.

I started wanting a library to for a LoRa telemetry field gateway and ended up writing one (which is usually not a good idea). My use case was a device that was configured, then run for long periods of time, was not battery powered, and if settings were changed could be restarted. I need to trial with some more hardware, frequency bands, variety of clients, initialisation configurations and backport the last round of fixes to my .NetMF library.

I am also looking at writing an RFM69 library using a pair of shields (434MHz & 915MHz)  from seegel-systeme.

The simplest possible application using the new library (a fair bit of the code is to support the different supported shields)

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// Copyright (c) August 2018, devMobile Software
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namespace devMobile.IoT.Rfm9x.LoRaDeviceClient
{
using System;
using System.Diagnostics;
using System.Text;
using System.Threading.Tasks;

using devMobile.IoT.Rfm9x;
using Windows.ApplicationModel.Background;

public sealed class StartupTask : IBackgroundTask
{
private byte NessageCount = Byte.MaxValue;
#if DRAGINO
private const byte ChipSelectLine = 25;
private const byte ResetLine = 17;
private const byte InterruptLine = 4;
private Rfm9XDevice rfm9XDevice = new Rfm9XDevice(ChipSelectPin.CS0, ChipSelectLine, ResetLine, InterruptLine);
#endif
#if M2M
private const byte ChipSelectLine = 25;
private const byte ResetLine = 17;
private const byte InterruptLine = 4;
private Rfm9XDevice rfm9XDevice = new Rfm9XDevice(ChipSelectPin.CS0, ChipSelectLine, ResetLine, InterruptLine);
#endif
#if ELECROW
private const byte ResetLine = 22;
private const byte InterruptLine = 25;
private Rfm9XDevice rfm9XDevice = new Rfm9XDevice(ChipSelectPin.CS1, ResetLine, InterruptLine);
#endif
#if ELECTRONIC_TRICKS
private const byte ResetLine = 22;
private const byte InterruptLine = 25;
private Rfm9XDevice rfm9XDevice = new Rfm9XDevice(ChipSelectPin.CS0, 22, 25);
#endif

public void Run(IBackgroundTaskInstance taskInstance)
{
rfm9XDevice.Initialise(Rfm9XDevice.RegOpModeMode.ReceiveContinuous, 915000000.0, paBoost: true);

#if DEBUG
rfm9XDevice.RegisterDump();
#endif
rfm9XDevice.OnReceive += Rfm9XDevice_OnReceive;
rfm9XDevice.OnTransmit += Rfm9XDevice_OnTransmit;

Task.Delay(10000).Wait();

while (true)
{
string messageText = string.Format("Hello W10 IoT Core LoRa! {0}", NessageCount);
NessageCount -= 1;

byte[] messageBytes = UTF8Encoding.UTF8.GetBytes(messageText);
Debug.WriteLine("{0:HH:mm:ss}-TX {1} byte message {2}", DateTime.Now, messageBytes.Length, messageText);
this.rfm9XDevice.Send(messageBytes);

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

private void Rfm9XDevice_OnReceive(object sender, Rfm9XDevice.OnDataReceivedEventArgs e)
{
try
{
string messageText = UTF8Encoding.UTF8.GetString(e.Data);

Debug.WriteLine("{0:HH:mm:ss}-RX {1} byte message {2}", DateTime.Now, e.Data.Length, messageText);
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}

private void Rfm9XDevice_OnTransmit(object sender, Rfm9XDevice.OnDataTransmitedEventArgs e)
{
Debug.WriteLine("{0:HH:mm:ss}-TX Done", DateTime.Now);
}
}
}

I have a shield from uputronics on order which should arrive from the UK in roughly a week. This shield has two RFM9X devices onboard (In my case 434MHz & 915MHz) so it will be interesting to see how my library copes with two instances of the stack running together.

I need to do more testing (especially of the initialisation options) and will add basic device addressing soon so my field gateway will only see messages which it is interested in.