MultiWii

gregd72002 wrote:For checksum you start with size
xor with id
xor with all data bits

https://github.com/rpicopter/mw-service ... /msg.c#L22

gregd72002 wrote:It shouldn't be that difficult to port it to windows.

You will most likely need to port uart.c and shm.c.
uart.c should be straightforward
shm.c you will need to come up with an alternative, i.e CreateFileMapping, MapViewOfFile, etc

crow wrote:Hello,

i'm currently developing a cross platform application to control MWC via wifi for my Final year project, but i already hit the wall, i can't find out how to create a checksum, im using socket test and type the message directly to test it before starting with the code
lets say i want to send an

MSP_IDENT:
$M<[0][100][crc?]
36 77 60 49 48 48 [Checksum?]

_________
Solved and implimented using C# but,
________________________
Now im having a diffrent problem i've been searching for few days but i can't find the solution, after converting values and assembling the socket and send it i couldn't get any answer from the arduino considering that when i send it via a socket test android app i.e write the socket manually exp:(24 4d 3c 00 64 64) in Hex, i get an answer, i think it has somethink with the speed of transmission, this is my code:

Code: Select all

  public void setupSocket() {                            // Socket setup here
         try {                
             mySocket = new TcpClient(Host, Port);
             theStream = mySocket.GetStream();
             theWriter = new StreamWriter(theStream);
             theReader = new StreamReader(theStream);
             socketReady = true;
             cnx.Play ();                                //voice assistant "connected"
         }
         catch (Exception e) {
             Debug.Log("Socket error:" + e);                // catch any exceptions
             lostcnx.Play ();                                    //Disconnected voice assistant
         }
     }
     
     public void writeSocket(string theLine) {            // function to write data out
         if (!socketReady)
             return;
         string tmpString = theLine;
         
         theWriter.WriteLine(tmpString);
         theWriter.Flush();
 
                           /************i've tried also*************/
                            //tmpString = System.Convert.ToByte ("244d3c006464");
                           //String nx="24 4d 3c 00 64 64";
                           //writer(theLine, 0, theLine.Length);


     }
     
     public string readSocket() {                        // function to read data in
         if (!socketReady)
             return "";
         if (theStream.DataAvailable)
             return theReader.ReadLine();
 
         return "NoData";
     }

And this is the MSP code :

Code: Select all

 
         
         //send msp with payload
         private List<Byte> requestMSP(int msp, byte[] payload)
         {
             if (msp < 0)
             {
                 return null;
             }
             List<Byte> bf = new List<Byte>();
             foreach (byte c in MSP_HEADER.ToCharArray())
             {
                 bf.Add(c);
             }
             
             byte checksum = 0;
             byte pl_size = (byte)((payload != null ? (int)(payload.Length) : 0) & 0xFF);
             bf.Add(pl_size);
             checksum ^= (byte)(pl_size & 0xFF);
             
             bf.Add((byte)(msp & 0xFF));
             checksum ^= (byte)(msp & 0xFF);
             
             if (payload != null)
             {
                 foreach (byte b in payload)
                 {
                     bf.Add((byte)(b & 0xFF));
                     checksum ^= (byte)(b & 0xFF);
                 }
             }
             bf.Add(checksum);
             return (bf);
         }
         
         void sendRequestMSP(List<Byte> msp)
         {
             byte[] arr = new byte[msp.Count];
             int i = 0;
             foreach (byte b in msp)
             {
                 arr[i++] = b;
             }
             client.writeSocket(BitConverter.ToString(arr)); // send the complete byte sequence in one go
             string output=BitConverter.ToString(arr);
             Debug.Log (output);
         }

i've tried many possible solution the socket looks correct in the debug messages but i guess the hex values is converted in wrong way before sending, and i don't know if i can control the speed of transmition some how, the same as in the serial port baudrate !!
Thanks in advance

gregd72002 wrote:why are you using writeline and not simply write? Also are you sure you have setup the correct baud rate, etc? what's the output of bitconverter.toString?

gregd72002 wrote:you might also consider reporting number of bytes written. This would be good check to verify what's being sent out