When I first tried Over The Air Activation(OTAA) to connect to The Things Network(TTN) with my RAKwireless RAK4200 module it didn’t work. I built another test harness with an FTDI module so I could send AT commands with the RAK Serial Port Tool to my RAK4200 module.
The default baud rate is 115200 but I sent “at+set_config=device:uart:1:9600” to the RAK4200 module.
With the RAK Serial Port Tool I could get the RAK4200 connected to TTN and send unconfirmed messages. The sequence of commands I used was
at+set_config=lora:join_mode:0
at+set_config=lora:class:0
at+set_config=lora:region:AS923
at+set_config=lora:dev_eui:XXXX
at+set_config=lora:app_eui:XXXX
at+set_config=lora:app_key:XXXX
at+set_config=device:restart
at+join
at+send=lora:2:48656c6c6f204c6f526157414e
I then returned to my STM32F769I Discovery, RAK4200 Breakoutboard, Seeedstudio Grove Base Shield for Arduino and a Seeedstudio Grove-4 pin Female Jumper to Grove 4 pin Conversion Cable based test harness.
I modified the NetworkJoinOTAA sample(based on the asynchronous version of BreakOutSerial) to send the same sequence of AT commands and display the responses.
namespace devMobile.IoT.LoRaWAN.nanoFramework.RAK4200
{
using System;
using System.Diagnostics;
using System.IO.Ports;
using System.Threading;
public class Program
{
private const string SerialPortId = "COM6";
private const string DevEui = "...";
private const string AppEui = "...";
private const string AppKey = "...";
private const byte MessagePort = 1;
private const string Payload = "48656c6c6f204c6f526157414e"; // Hello LoRaWAN
public static void Main()
{
string response;
Debug.WriteLine("devMobile.IoT.Rak4200.NetworkJoinOTAA starting");
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
try
{
using (SerialPort serialDevice = new SerialPort(SerialPortId))
{
// set parameters
serialDevice.BaudRate = 9600;
//_SerialPort.BaudRate = 115200;
serialDevice.Parity = Parity.None;
serialDevice.StopBits = StopBits.One;
serialDevice.Handshake = Handshake.None;
serialDevice.DataBits = 8;
serialDevice.ReadTimeout = 10000;
serialDevice.NewLine = "\r\n";
serialDevice.DataReceived += SerialDevice_DataReceived;
serialDevice.Open();
serialDevice.WatchChar = '\n';
// clear out the RX buffer
serialDevice.ReadExisting();
response = serialDevice.ReadExisting();
Debug.WriteLine($"Response :{response.Trim()} bytes:{response.Length}");
Thread.Sleep(500);
// Set the Working mode to LoRaWAN
Console.WriteLine("lora:work_mode:0");
serialDevice.WriteLine("at+set_config=lora:work_mode:0");
// Set the JoinMode
Console.WriteLine("lora:join_mode");
serialDevice.WriteLine("at+set_config=lora:join_mode:0");
Thread.Sleep(500);
// Set the Class
Console.WriteLine("lora:class");
serialDevice.WriteLine("at+set_config=lora:class:0");
Thread.Sleep(500);
// Set the Region to AS923
Console.WriteLine("lora:region:AS923");
serialDevice.WriteLine("at+set_config=lora:region:AS923");
Thread.Sleep(500);
// Set the devEUI
Console.WriteLine("lora:dev_eui:{DevEui}");
serialDevice.WriteLine($"at+set_config=lora:dev_eui:{DevEui}");
Thread.Sleep(500);
// Set the appEUI
Console.WriteLine("lora:app_eui:{AppEui}");
serialDevice.WriteLine($"at+set_config=lora:app_eui:{AppEui}");
Thread.Sleep(500);
// Set the appKey
Console.WriteLine("lora:app_key:{AppKey}");
serialDevice.WriteLine($"at+set_config=lora:app_key:{AppKey}");
Thread.Sleep(500);
// Set the Confirm flag
Console.WriteLine("lora:confirm:0");
serialDevice.WriteLine("at+set_config=lora:confirm:0");
Thread.Sleep(500);
// Reset the device
Console.WriteLine("device:restart");
serialDevice.WriteLine($"at+set_config=device:restart");
Thread.Sleep(10000);
// Join the network
Console.WriteLine("at+join");
serialDevice.WriteLine("at+join");
Thread.Sleep(10000);
while (true)
{
// Send the BCD messages
Console.WriteLine("lora:{MessagePort}:{Payload}");
serialDevice.WriteLine($"at+send=lora:{MessagePort}:{Payload}");
Thread.Sleep(20000);
}
}
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
private static void SerialDevice_DataReceived(object sender, SerialDataReceivedEventArgs e)
{
SerialPort serialPort = (SerialPort)sender;
string response;
switch (e.EventType)
{
case SerialData.Chars:
break;
case SerialData.WatchChar:
response = serialPort.ReadExisting();
Debug.Write(response);
break;
default:
Debug.Assert(false, $"e.EventType {e.EventType} unknown");
break;
}
}
}
}
The NetworkJoinOTAA application assumes that all of the AT commands succeed
I need to find a way to set the RAK4200 back to factory settings so I can figure out what settings are persisted by the “at+set_config=device:restart” and which ones need to be set every time the application is run.
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