Random wanderings through Microsoft Azure esp. PaaS plumbing, the IoT bits, AI on Micro controllers, AI on Edge Devices, .NET nanoFramework, .NET Core on *nix and ML.NET+ONNX
The RAK2305 WisBlock Wifi Interface Module has the TX0 pin is connected to pin 11, RX0 is connected to pin 12, TX1 pin (Gpio.IO21) is connected to pin 34, and the RX1 pin (Gpio.IO21) is connected to pin 33 of the IO Slot connector (crossover TX & RX).
The RAK4630 Module is plugged into the CPU slot (BTB40_F) of the RAK5005 Base Board with TX pin 33 and RX pin 34. The RAK4630 Module UART2_TX pin is connected to 33, and the UART2_RX is connected to 34 on the CPU slot.
I then read the RAK4630 AT Command documentation to see if I could enable AT Commands on the second serial port
I had a look at the RAK4360 RAK Unified Interface (RUI) code to see if I could modify it so UART1 responded to AT Commands but I’m not certain this would work.
This is a longish post about failure, it took many hours to explore all the different approaches which was way longer than I should have spent. For why see “sunk cost fallacy”
When I initially deployed the RAK4200LoRaWANDeviceClient the RAK4200LoRaWAN-NetNF library failed in the OtaaInitialise method. I think this was caused by the “at+set_config=lora:work_mode:0” command rebooting the RAK4200 Module. I have commented out the code but may move it to a standalone method if required.
// Set the Working mode to LoRaWAN, not/never going todo P2P with this library.
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} at+set_config=lora:work_mode:0");
#endif
Result result = SendCommand("Initialization OK", "at+set_config=lora:work_mode:0", CommandTimeoutDefault);
if (result != Result.Success)
{
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} at+set_config=lora:work_mode:0 failed {result}");
#endif
return result;
}
I think it would be reasonable to assume that the device is in the correct mode (the default after a reset to factory) on startup so I removed the LoRa® network work mode configuration code.
// Set the Working mode to LoRaWAN, not/never going todo P2P with this library.
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} AT+NWM=1");
#endif
Result result = SendCommand("Current Work Mode: LoRaWAN.", "AT+NWM=1", CommandTimeoutDefault);
if (result != Result.Success)
{
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} AT+NWM=1 failed {result}");
#endif
return result;
}
I think it would be reasonable to assume that the device is in the correct mode (the default after a reset to factory) on startup so I removed the LoRa® network work mode configuration code.
Visual Studio Debug output for RAK3172LoRaWANDeviceClient minimal configuration
public static void Main()
{
Result result;
Debug.WriteLine("devMobile.IoT.RAK3172LoRaWANDeviceClient starting");
try
{
// set GPIO functions for COM2 (this is UART1 on ESP32)
#if ESP32_WROOM
Configuration.SetPinFunction(Gpio.IO17, DeviceFunction.COM2_TX);
Configuration.SetPinFunction(Gpio.IO16, DeviceFunction.COM2_RX);
#endif
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
using (Rak3172LoRaWanDevice device = new Rak3172LoRaWanDevice())
{
result = device.Initialise(SerialPortId, 115200, Parity.None, 8, StopBits.One);
if (result != Result.Success)
{
Debug.WriteLine($"Initialise failed {result}");
return;
}
MessageSendTimer = new Timer(SendMessageTimerCallback, device, Timeout.Infinite, Timeout.Infinite);
device.OnJoinCompletion += OnJoinCompletionHandler;
device.OnReceiveMessage += OnReceiveMessageHandler;
#if CONFIRMED
device.OnMessageConfirmation += OnMessageConfirmationHandler;
#endif
#if FACTORY_RESET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} FactoryReset");
result = device.FactoryReset();
if (result != Result.Success)
{
Debug.WriteLine($"FactoryReset failed {result}");
return;
}
#endif
#if DEVICE_DEVEUI_SET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Device EUI");
result = device.DeviceEui(Config.devEui);
if (result != Result.Success)
{
Debug.WriteLine($"DeviceEUI set failed {result}");
return;
}
#endif
#if REGION_SET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Region{Band}");
result = device.Band(Band);
if (result != Result.Success)
{
Debug.WriteLine($"Band on failed {result}");
return;
}
#endif
#if ADR_SET
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} ADR On");
result = device.AdrOn();
if (result != Result.Success)
{
Debug.WriteLine($"ADR on failed {result}");
return;
}
#endif
#if CONFIRMED
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Confirmed");
result = device.UplinkMessageConfirmationOn();
if (result != Result.Success)
{
Debug.WriteLine($"Confirm on failed {result}");
return;
}
#endif
#if UNCONFIRMED
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Unconfirmed");
result = device.UplinkMessageConfirmationOff();
if (result != Result.Success)
{
Debug.WriteLine($"Confirm off failed {result}");
return;
}
#endif
#if OTAA
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} OTAA");
result = device.OtaaInitialise(Config.JoinEui, Config.AppKey);
if (result != Result.Success)
{
Debug.WriteLine($"OTAA Initialise failed {result}");
return;
}
#endif
#if ABP
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} ABP");
result = device.AbpInitialise(Config.DevAddress, Config.NwksKey, Config.AppsKey);
if (result != Result.Success)
{
Debug.WriteLine($"ABP Initialise failed {result}");
return;
}
#endif
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Join start Timeout:{JoinTimeOut:hh:mm:ss}");
result = device.Join(JoinTimeOut);
if (result != Result.Success)
{
Debug.WriteLine($"Join failed {result}");
return;
}
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Join started");
Thread.Sleep(Timeout.Infinite);
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
One of the major differences between the RAK4200 and RAK3127 libraries is the way a LoRaWAN network join is handled. The RAK4200 library Join method blocks until it succeeds of fails, the RAK3172 library Join method returns immediately then an EventHandler is called with the result.
Initially the Sleep method didn’t appear to work, the power consumption didn’t change….
private static void SendMessageTimerCallback(object state)
{
Rak3172LoRaWanDevice device = (Rak3172LoRaWanDevice)state;
#if PAYLOAD_HEX
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} port:{MessagePort} payload HEX:{PayloadHex}");
Result result = device.Send(MessagePort, PayloadHex, SendTimeout);
#endif
#if PAYLOAD_BYTES
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} port:{MessagePort} payload bytes:{Rak3172LoRaWanDevice.BytesToHex(PayloadBytes)}");
Result result = device.Send(MessagePort, PayloadBytes, SendTimeout);
#endif
if (result != Result.Success)
{
Debug.WriteLine($"Send failed {result}");
}
#if SLEEP
Thread.Sleep(7500); //10000 Works 5000 to short
Debug.WriteLine($"{DateTime.UtcNow:hh:mm:ss} Sleep period:{SleepPeriod:hh:mm:ss}");
result = device.Sleep(SleepPeriod);
if (result != Result.Success)
{
Debug.WriteLine($"Sleep failed {result}");
return;
}
#endif
}
After some debugging and reading this helpful RAK Wireless forum post I added a short delay before sleeping the RAK3172 module and power consumption reduced.
Initially the Sleep method timed out every time it was called. After some more debugging I figured out that I needed a slightly longer delay for the AutoResetEvent.Waitone as it was timing out just before the “OK” was processed.
public Result Sleep(TimeSpan period)
{
return Sleep(period, SleepExtensionDefault);
}
public Result Sleep(TimeSpan period, TimeSpan extension)
{
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} AT+SLEEP {period.TotalMilliseconds:f0} mSec");
#endif
Result result = SendCommand("OK", $"AT+SLEEP={period.TotalMilliseconds:f0}", period.Add(extension));
if (result != Result.Success)
{
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} AT+SLEEP failed {result}");
#endif
return result;
}
return Result.Success;
}
public static void Main()
{
Debug.WriteLine("devMobile.IoT.LoRaWAN.nanoFramework.RAK3172 BreakoutSerial starting");
try
{
// set GPIO functions for COM2 (this is UART1 on ESP32)
#if ESP32_WROOM
Configuration.SetPinFunction(Gpio.IO17, DeviceFunction.COM2_TX);
Configuration.SetPinFunction(Gpio.IO16, DeviceFunction.COM2_RX);
#endif
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
using (_SerialPort = new SerialPort(SerialPortId))
{
// set parameters
_SerialPort.BaudRate = 115200;
_SerialPort.Parity = Parity.None;
_SerialPort.DataBits = 8;
_SerialPort.StopBits = StopBits.One;
_SerialPort.Handshake = Handshake.None;
_SerialPort.NewLine = "\r\n";
_SerialPort.ReadTimeout = 1000;
//_SerialPort.WatchChar = '\n'; // May 2022 WatchChar event didn't fire github issue https://github.com/nanoframework/Home/issues/1035
#if SERIAL_ASYNC_READ
_SerialPort.DataReceived += SerialDevice_DataReceived;
#endif
_SerialPort.Open();
_SerialPort.WatchChar = '\n';
_SerialPort.ReadExisting(); // Running at 115K2 this was necessary
...
for (int i = 0; i < 5; i++)
{
string atCommand;
atCommand = "AT+VER=?";
//atCommand = "AT+SN=?"; // Empty response?
//atCommand = "AT+HWMODEL=?";
//atCommand = "AT+HWID=?";
//atCommand = "AT+DEVEUI=?";
//atCommand = "AT+APPEUI=?";
//atCommand = "AT+APPKEY=?";
//atCommand = "ATR";
//atCommand = "AT+SLEEP=4000";
Debug.WriteLine("");
Debug.WriteLine($"{i} TX:{atCommand} bytes:{atCommand.Length}--------------------------------");
_SerialPort.WriteLine(atCommand);
Thread.Sleep(5000);
}
}
...
Debug.WriteLine("Done");
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
After resetting the device I modified the code to display some of the configuration.
DevEUI after ATR command
JoinEUI after ATR command
AppKey after ATR command
To reconfigure the device I ran the RAK3172LoRaWANDeviceClient application with DEVICE_DEVEUI_SET, OTAA, UNCONFIRMED, REGION_SET and ADR_SET defined. The testrig could then successfully connect to The Things Network and when the device was power cycled the configuration was retained.
public Result FactoryReset()
{
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} ATR");
#endif
Result result = SendCommand("OK", "ATR", CommandTimeoutDefault);
if (result != Result.Success)
{
#if DIAGNOSTICS
Debug.WriteLine($" {DateTime.UtcNow:hh:mm:ss} ATR failed {result}");
#endif
return result;
}
return Result.Success;
}
I modified the NetworkJoinOTAA sample(based on the asynchronous version of BreakOutSerial) to send the required sequence of AT commands and displays the responses.
namespace devMobile.IoT.LoRaWAN.nanoFramework.RAK3172
{
using System;
using System.Diagnostics;
using System.IO.Ports;
using System.Threading;
#if ESP32_WROOM
using global::nanoFramework.Hardware.Esp32; //need NuGet nanoFramework.Hardware.Esp32
#endif
public class Program
{
#if ESP32_WROOM
private const string SerialPortId = "COM2";
#endif
#if ST_STM32F769I_DISCOVERY
private const string SerialPortId = "COM6";
#endif
private const string DevEui = "...";
private const string DevAddress = "...";
private const string NwksKey = "...";
private const string AppsKey = "...";
private const byte MessagePort = 1;
private const string Payload = "A0EEE456D02AFF4AB8BAFD58101D2A2A"; // Hello LoRaWAN
public static void Main()
{
Debug.WriteLine("devMobile.IoT.LoRaWAN.nanoFramework.RAK3172.NetworkJoinABP starting");
try
{
// set GPIO functions for COM2 (this is UART1 on ESP32)
#if ESP32_WROOM
Configuration.SetPinFunction(Gpio.IO17, DeviceFunction.COM2_TX);
Configuration.SetPinFunction(Gpio.IO16, DeviceFunction.COM2_RX);
#endif
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
using (SerialPort serialPort = new SerialPort(SerialPortId))
{
// set parameters
serialPort.BaudRate = 115200;
serialPort.Parity = Parity.None;
serialPort.DataBits = 8;
serialPort.StopBits = StopBits.One;
serialPort.Handshake = Handshake.None;
serialPort.NewLine = "\r\n";
serialPort.ReadTimeout = 1000;
serialPort.DataReceived += SerialDevice_DataReceived;
serialPort.Open();
serialPort.WatchChar = '\n';
serialPort.ReadExisting(); // Running at 115K2 this was necessary
// Set the Device EUI
Console.WriteLine("Set Device EUI");
serialPort.WriteLine($"AT+DEVEUI={DevEui}");
// Set the Working mode to LoRaWAN
Console.WriteLine("Set Work mode");
serialPort.WriteLine("AT+NWM=1");
// Set the Region to AS923
Console.WriteLine("Set Region");
serialPort.WriteLine("AT+BAND=8");
// Set the JoinMode
Console.WriteLine("Set Join mode");
serialPort.WriteLine("AT+NJM=0");
// Set the DevAddress
Console.WriteLine("Set Device Address");
serialPort.WriteLine($"AT+DEVADDR={DevAddress}");
// Set the Network Session Key
Console.WriteLine("Set NwksKey");
serialPort.WriteLine($"AT+NWKSKEY={NwksKey}");
// Set the Application Session Key
Console.WriteLine("Set AppsKey");
serialPort.WriteLine($"AT+APPSKEY={AppsKey}");
// Set the Confirm flag
Console.WriteLine("Set Confirm off");
serialPort.WriteLine("AT+CFM=0");
// Join the network
Console.WriteLine("Start Join");
serialPort.WriteLine("AT+JOIN=1:0:10:2");
// Wait for the +EVT:JOINED
while (true)
{
Console.WriteLine("Sending");
serialPort.WriteLine($"AT+SEND={MessagePort}:{Payload}");
Thread.Sleep(300000);
}
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
private static void SerialDevice_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
SerialPort serialPort = (SerialPort)sender;
switch (e.EventType)
{
case SerialData.Chars:
break;
case SerialData.WatchChar:
string response = serialPort.ReadExisting();
Debug.Write(response);
break;
default:
Debug.Assert(false, $"e.EventType {e.EventType} unknown");
break;
}
}
}
}
The NetworkJoinABP application assumes that all of the AT commands succeed.
TTN Console live data tab connection process
Visual Studio Output windows displaying connection process and a D2C message
TTN Console live data tab connection process with a couple of D2C messages
Visual Studio Output windows displaying connection process and a couple of C2D messages
devMobile's blog 