The RAKwireless RAK4200 module has a really useful “reset to factory” AT Command
at+set_config=lora:default_parameters
To see what settings were erased I modified the BreakOutSerial application to send additional AT commands and display the responses.
public static void Main()
{
...
Debug.WriteLine("devMobile.IoT.LoRaWAN.nanoFramework.RAK4200 BreakoutSerial starting");
try
{
// set GPIO functions for COM2 (this is UART1 on ESP32)
#if ESP32_WROOM
Configuration.SetPinFunction(Gpio.IO16, DeviceFunction.COM2_TX);
Configuration.SetPinFunction(Gpio.IO17, DeviceFunction.COM2_RX);
#endif
Debug.Write("Ports:");
foreach (string port in SerialPort.GetPortNames())
{
Debug.Write($" {port}");
}
Debug.WriteLine("");
using (_SerialPort = new SerialPort(SerialPortId))
{
// set parameters
_SerialPort.BaudRate = 9600;
//_SerialPort.BaudRate = 115200;
_SerialPort.Parity = Parity.None;
_SerialPort.DataBits = 8;
_SerialPort.StopBits = StopBits.One;
_SerialPort.Handshake = Handshake.None;
_SerialPort.NewLine = "\r\n";
//_SerialPort.ReadBufferSize = 128;
//_SerialPort.ReadBufferSize = 256;
_SerialPort.ReadBufferSize = 512;
//_SerialPort.ReadBufferSize = 1024;
_SerialPort.ReadTimeout = 1000;
//_SerialPort.WatchChar = '\n'; // May 2022 WatchChar event didn't fire github issue https://github.com/nanoframework/Home/issues/1035
#if SERIAL_ASYNC_READ
_SerialPort.DataReceived += SerialDevice_DataReceived;
#endif
_SerialPort.Open();
_SerialPort.WatchChar = '\n';
...
for (int i = 0; i < 5; i++)
{
string atCommand;
atCommand = "at+version";
//atCommand = "at+set_config=device:uart:1:9600";
atCommand = "at+get_config=lora:status";
//atCommand = "at+get_config=device:status";
//atCommand = "at+get_config=lora:channel";
//atCommand = "at+help";
//atCommand = "at+set_config=device:restart";
//atCommand = "at+set_config=lora:default_parameters";
Debug.WriteLine("");
Debug.WriteLine($"{i} TX:{atCommand} bytes:{atCommand.Length}--------------------------------");
_SerialPort.WriteLine(atCommand);
Thread.Sleep(5000);
}
}
Debug.WriteLine("Done");
}
catch (Exception ex)
{
Debug.WriteLine(ex.Message);
}
}
#if SERIAL_ASYNC_READ
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;
}
}
#endif
...
}
After configuring my Sparkfun Thing Plus ESP32 WROOM + RAK42000 Breakout Board test rig the RAK4200LoRaWANDeviceClient application could successfully connect to The Things Network .
The thread '' (0x2) has exited with code 0 (0x0).
devMobile.IoT.LoRaWAN.nanoFramework.RAK4200 BreakoutSerial starting
0 TX:at+get_config=lora:status bytes:25--------------------------------
OK Work Mode: LoRaWAN
Region: AS923
MulticastEnable: false
DutycycleEnable: false
Send_repeat_cnt: 0
Join_mode: OTAA
DevEui: 6..............9
AppEui: 7..............4
AppKey: A.............................9
Class: A
Joined Network:false
IsConfirm: unconfirm
AdrEnable: true
EnableRepeaterSupport: false
RX2_CHANNEL_FREQUENCY: 923200000, RX2_CHANNEL_DR:2
RX_WINDOW_DURATION: 3000ms
RECEIVE_DELAY_1: 1000ms
RECEIVE_DELAY_2: 2000ms
JOIN_ACCEPT_DELAY_1: 5000ms
JOIN_ACCEPT_DELAY_2: 6000ms
Current Datarate: 5
Primeval Datarate: 5
ChannelsTxPower: 0
UpLinkCounter: 0
DownLinkCounter: 0
I then reset the RAK4200 device to “factory defaults”
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
devMobile.IoT.LoRaWAN.nanoFramework.RAK4200 BreakoutSerial starting
Ports: COM5 COM6
0 TX:at+set_config=lora:default_parameters bytes:37--------------------------------
OK
The testrig would no longer connect as the device and network settings were invalid.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
devMobile.IoT.LoRaWAN.nanoFramework.RAK4200 BreakoutSerial starting
Ports: COM5 COM6
0 TX:at+get_config=lora:status bytes:25--------------------------------
OK Work Mode: LoRaWAN
Region: AS923
MulticastEnable: false
DutycycleEnable: false
Send_repeat_cnt: 0
Join_mode: OTAA
DevEui: 0000000000000000
AppEui: 0000000000000000
AppKey: 00000000000000000000000000000000
Class: A
Joined Network:false
IsConfirm: unconfirm
AdrEnable: true
EnableRepeaterSupport: false
RX2_CHANNEL_FREQUENCY: 923200000, RX2_CHANNEL_DR:2
RX_WINDOW_DURATION: 3000ms
RECEIVE_DELAY_1: 1000ms
RECEIVE_DELAY_2: 2000ms
JOIN_ACCEPT_DELAY_1: 5000ms
JOIN_ACCEPT_DELAY_2: 6000ms
Current Datarate: 5
Primeval Datarate: 5
ChannelsTxPower: 0
UpLinkCounter: 0
DownLinkCounter: 0
To “restore” the device configuration I ran the RAK4200LoRaWANDeviceClient application with DEVICE_DEVEUI_SET, OTAA, UNCONFIRMED, REGION_SET and ADR_SET defined.
The thread '<No Name>' (0x2) has exited with code 0 (0x0).
devMobile.IoT.LoRaWAN.nanoFramework.RAK4200 BreakoutSerial starting
Ports: COM2 COM3
0 TX:at+get_config=lora:status bytes:25--------------------------------
OK Work Mode: LoRaWAN
Region: AS923
MulticastEnable: false
DutycycleEnable: false
Send_repeat_cnt: 0
Join_mode: OTAA
DevEui: 6..............9
AppEui: 7.............4
AppKey: A.............................9
Class: A
Joined Network:false
IsConfirm: unconfirm
AdrEnable: true
EnableRepeaterSupport: false
RX2_CHANNEL_FREQUENCY: 923200000, RX2_CHANNEL_DR:2
RX_WINDOW_DURATION: 3000ms
RECEIVE_DELAY_1: 1000ms
RECEIVE_DELAY_2: 2000ms
JOIN_ACCEPT_DELAY_1: 5000ms
JOIN_ACCEPT_DELAY_2: 6000ms
Current Datarate: 5
Primeval Datarate: 5
ChannelsTxPower: 0
UpLinkCounter: 0
DownLinkCounter: 0
The testrig would then successfully connect to The Things Network. When the testrig was power cycled the device the configuration was retained.
devMobile's blog 
Pingback: .NET nanoFramework RAK4200 Library Usage | devMobile's blog