After writing Windows 10 IoT Core & .NetMF RFM9X libraries I figured a port to a Wilderness Labs Meadow device shouldn’t be “rocket science”.
To get started I used a Dragino LoRa shield for Arduino which looked compatible with my Meadow device.
The shield ships with the SPI lines configured for ICSP so the three jumpers diagonally across the shield from the antenna connector need to be swapped to the side closest to the edge of the shield.
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// Copyright (c) Dec 2019, devMobile Software
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// Licensed under the Apache License, Version 2.0 (the "License");
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// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
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namespace devMobile.IoT.Rfm9x
{
using System;
using System.Threading.Tasks;
using Meadow;
using Meadow.Devices;
using Meadow.Hardware;
public class MeadowApp : App<F7Micro, MeadowApp>
{
const byte RegVersion = 0x42;
ISpiBus spiBus;
SpiPeripheral sx127xDevice;
IDigitalOutputPort spiPeriphChipSelect;
public MeadowApp()
{
ConfigureSpiPort();
//ReadDeviceID();
ReadDeviceIDDiy();
}
public void ConfigureSpiPort()
{
try
{
spiBus = Device.CreateSpiBus(500);
if (spiBus == null)
{
Console.WriteLine("spiBus == null");
}
Console.WriteLine("Creating SPI NSS Port...");
spiPeriphChipSelect = Device.CreateDigitalOutputPort(Device.Pins.D09);
if (spiPeriphChipSelect == null)
{
Console.WriteLine("spiPeriphChipSelect == null");
}
Console.WriteLine("sx127xDevice Device...");
sx127xDevice = new SpiPeripheral(spiBus, spiPeriphChipSelect);
if (sx127xDevice == null)
{
Console.WriteLine("sx127xDevice == null");
}
Console.WriteLine("ConfigureSpiPort Done...");
}
catch (Exception ex)
{
Console.WriteLine("ConfigureSpiPort " + ex.Message);
}
}
public void ReadDeviceID()
{
Task.Delay(500).Wait();
while (true)
{
try
{
Console.WriteLine("sx127xDevice.ReadRegister...1");
byte registerValue = sx127xDevice.ReadRegister(RegVersion);
Console.WriteLine("sx127xDevice.ReadRegister...2");
Console.WriteLine("Register 0x{0:x2} - Value 0X{1:x2} - Bits {2}", RegVersion, registerValue, Convert.ToString(registerValue, 2).PadLeft(8, '0'));
}
catch (Exception ex)
{
Console.WriteLine("ReadDeviceID " + ex.Message);
}
Task.Delay(10000).Wait();
}
}
public void ReadDeviceIDDiy()
{
var txBuffer = new byte[2];
var rxBuffer = new byte[2];
Task.Delay(500).Wait();
while (true)
{
try
{
Console.WriteLine("spiBus.ExchangeData...1");
txBuffer[0] = RegVersion;
spiBus.ExchangeData(spiPeriphChipSelect, ChipSelectMode.ActiveLow, txBuffer, rxBuffer, 2);
Console.WriteLine("spiBus.ExchangeData...2");
byte registerValue = rxBuffer[1];
Console.WriteLine("Register 0x{0:x2} - Value 0X{1:x2} - Bits {2}", RegVersion, registerValue, Convert.ToString(registerValue, 2).PadLeft(8, '0'));
}
catch (Exception ex)
{
Console.WriteLine("ReadDeviceIDDiy " + ex.Message);
}
Task.Delay(10000).Wait();
}
}
}
}
After some trial and error (using beta 3.6) I found that the ReadRegister method didn’t work as expected (possibly related to this issue) and I had to manually assemble the request to read the SX127X RegVersion register.
'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\RFX9X.Meadow\FeatherWingSPI\bin\Debug\net472\App.exe'. Symbols loaded.
'App.exe' (CLR v4.0.30319: App.exe): Loaded 'C:\Users\BrynLewis\source\repos\RFX9X.Meadow\FeatherWingSPI\bin\Debug\net472\Meadow.dll'.
The program '[22324] App.exe: Program Trace' has exited with code 0 (0x0).
The program '[22324] App.exe' has exited with code 0 (0x0).
.
.
DirectRegisterAccess = True
==========================================================
Ignore the exceptions generated by the DateTime call here.
==========================================================
.
Creating SPI NSS Port...
sx127xDevice Device...
ConfigureSpiPort Done...
spiBus.ExchangeData...1
spiBus.ExchangeData...2
Register 0x42 - Value 0X12 - Bits 00010010
spiBus.ExchangeData...1
spiBus.ExchangeData...2
Register 0x42 - Value 0X12 - Bits 00010010
spiBus.ExchangeData...1
spiBus.ExchangeData...2
Register 0x42 - Value 0X12 - Bits 00010010
spiBus.ExchangeData...1
spiBus.ExchangeData...2
