Softata: Service Commands - 1


Commands are sent from the .NET library (Softalib) which is the client, to the WiFi TCPIP Service running on the Arduino device. An outlive of the client-server code.

Server Communication

Server Setup

#include <WiFi.h>
const char* ssid = "SSID";
const char* password = "PWD";
int port = PORT;
WiFiServer server(port);

void setup() {
  WiFi.mode(WIFI_STA);
  WiFi.setHostname("PicoW2");
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    Serial.print(".");
    delay(100);
  }
  Serial.printf("\nConnected to WiFi\n\nConnect to server at %s:%d\n", WiFi.localIP().toString().c_str(), port);
  server.begin();
}

Server Message Reception

  WiFiClient client = server.available();
  while (true) {
    watchdog_update();
    while (!client.available()) {
      delay(100);
      watchdog_update();
    }
    byte length = client.read();
    int count = 0;
    byte msg[maxRecvdMsgBytes];
    if (length == 0) {
      return;
    }
    while (client.available() && (count != length)) {
      msg[count] = client.read();;
      watchdog_update();
      count++;
    }
    if (count != length) {
        //Errant condition
    }
    // Process the received message ...
    ...

So the process is to read the first byte of message as the length of message then read that many bytes into a byte array (not including that first byte).

Basic Client Communication

Send

    List<byte> sendmsg = new List<byte> { 0,(byte)MsgType }
    // Add other byte data
    sendmsg[0] = (byte)(sendmsg.Count-1);
    // Get bytes from list.
    byte[] sendBytes = sendmsg.ToArray<byte>();
    int sent = client.Send(sendBytes, 0, sendBytes.Length, SocketFlags.None);

Receive Response

    //Wait for response
    while (client.Available == 0) ;
    byte[] data = new byte[100]; //Received msg limited top 100 bytes
    int recvd = client.Receive(data);

    string result = Encoding.UTF8.GetString(data).Substring(0, recvd);

    // Make the check work in both ways.
    // expect is typically "OK:"
    if ((!expect.Contains(result)) && (!result.Contains(expect)))
    {
        // Errant condition
    }
    // Return result string

Basic Server Commands

These start with an ASCII code for an ASCII uppercase character, the first letter of basic command names:

   switch (msg[0]) {
      case (byte)'B':  // Begin
        client.print("Ready");  // Sent at start connection.
        break;
      case (byte)'E':  //End
        client.print("Done");
        // Force reset
        resetFunc();
        break;
      case (byte)'N':  //Null
        client.print("OK");
        return;
        break;
      case (byte)'R':  //Reset
        client.print("Reset");
        // Force reset
        resetFunc();
       case (byte)'V':  //Get Version
        client.print(APP_VERSION);
        break;
       case (byte)'D':  //Get Device Types
       {
        String devicesCSV = Grove::GetListofDevices();
        client.print(devicesCSV);
       }
        break;
       default:
        //Process other commands

Other high level commands can be added here filling in the gaps in the range A to Z.

Nb: Softata commands not to be between 65 to 90, 0x41 to 0x5A, ‘A’ to ‘Z’.

C## Implementation of Basic Commands

The Console app starts with these calls to the Softatalib that then forwards them to the service.

    SoftataLib.Init(ipaddressStr, port);

    SoftataLib.SendMessageCmd("Begin");
    string Version = SoftataLib.SendMessageCmd("Version");
    Console.WriteLine($"Softata Version: {Version}");
    string devicesCSV = SoftataLib.SendMessageCmd("Devices");
    Console.WriteLine($"{devicesCSV}");

Console app initialization

The first SoftataLib call sets up the client and does not communicate with the service.

    public static string SendMessageCmd(string cmd)
    {
        // Construct command and parameters as list of bytes
        List<byte> sendmsg = new List<byte> { 1, (byte)cmd[0] };

        byte[] sendBytes = sendmsg.ToArray<byte>();
        int sent = client.Send(sendBytes, 0, sendBytes.Length, SocketFlags.None);

        //Wait for response
        while (client.Available == 0) ;
        byte[] data = new byte[100];
        int recvd = client.Receive(data);

        string result = Encoding.ASCII.GetString(data).Substring(0, recvd).Trim();;
        switch (cmd)
        {
            // If data is expected to be returned, return the result. 
            // Note: The expect validation mechanism not used here.
            // If the command was end, shut the client down so the at app can exit:
            case end:
                Thread.Sleep(2000);
                client.Shutdown(SocketShutdown.Both);
                client.Close();
                break;
        }
    }

Softatalib.SendMessageCmd()

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