AT/SST/CVT MUT communication

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Nov 30, 2009, 10:15 PM

#16

acamus

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Quote:

Originally Posted by fostytou

Oh no, not the break switch!

Thanks for your continuing efforts. Do the drive/neutral flags apply to manual cars as well or are they specifically flagged based off the TCU?

The MUT requests above are actual processor input pin states, so unless the wire is physically connected, the flags will not be set. The question is if they propagate to something common for both AT/MT ECU, frankly I have not had a look yet.

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Nov 30, 2009, 11:33 PM

#17

knochgoon24

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Quote:

Originally Posted by acamus

I have disassembled Galant/Lancer/Eclipse/EVO AT ECU, they are all the same, in the sense of MUT requests but unfortunatelly I do not have H8 AT ECU so I cannot confirm.
Maybe you can simply connect the cable and test it out

I may just do that.

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Dec 1, 2009, 12:36 PM

#18

acamus

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I have found the Init byte for AT MUT, credit goes to Ceddy for idea of sending all 256 values at 5 baud.)
The init code is 0x3, so incredibly simple

Then switching to 15625 and sending AT MUT requests.

I believe my quest is now finished, until some interest is shown (nads, mattjin still around?) and Hamish will incorporate it to EvoScan :P

@Hamish, here is a class that you may find useful (C#)

Code:

  
    public class FiveBaudRateSender  
    {
        private SerialPort serialPort { get; set; }

        public FiveBaudRateSender(SerialPort aPort)
        {
            serialPort = aPort;
        }

        public void SendByte(byte aByte)
        {  
           SendStartBit();   
           SendBits(aByte);   
           SendStopBit();   
           SendPause();  
        }

        private void SendPause()
        {
             serialPort.BreakState = false;
             Thread.Sleep(50);              
        }

        private void SendStopBit()
        {
            byte[] aBytes = new byte[1] { 1 };
            BitArray aBA = new BitArray( aBytes );
            Transmit( aBA, 1 );
        }

        private void SendStartBit()
        {
             byte[] aBytes = new byte[1] { 0 };
            BitArray aBA = new BitArray( aBytes );
            Transmit( aBA, 1 );
        }

        private void SendBits(byte aByte)
       {
          byte[] aBytes = new byte[1] { aByte };
          BitArray aBA = new BitArray( aBytes );
          Transmit( aBA, 8 );     
       }

       private void Transmit(BitArray aList, int aWidth)
       {      
          for ( int i = 0; i <= aWidth-1; i++)
          {
             serialPort.BreakState=!aList[i];
             Thread.Sleep(200);         
          }
       }

    }

and code example

Code:

            if(serialPort.IsOpen)
            {
            	FiveBaudRateSender aSender = new FiveBaudRateSender(serialPort);
                aSender.SendByte((byte)0x3);
            }

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Dec 1, 2009, 03:05 PM

#19

logic

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Quote:

Originally Posted by acamus

Code:

       private void Transmit(BitArray aList, int aWidth)
       {      
          for ( int i = 0; i <= aWidth-1; i++)
          {
             serialPort.BreakState=!aList[i];
             Thread.Sleep(200);         
          }
       }

Hah, that looks familiar!

Code:

class OBDInit:
    BAUD = 10500
    INITBYTE = 0x33
    INITBAUD = 5

    def __init__(self, fd):
        self.fd = fd                  # s/b serial.Serial()
        self.fd.setBaudRate(self.BAUD)
        self.fd.setByteSize(8)
        self.fd.setParity('N')
        self.fd.setStopbits(1)
        self.fd.flush()

        bits = self.INITBYTE
        initdelay = 1.0/self.INITBAUD
        for _ in range(9):            # 9 gives implicit stop bit w/shifting.
            if bits & 1:
                self.fd.setRTS(True)
                self.fd.setDTR(True)
            else:
                self.fd.setDTR(False)
                self.fd.setRTS(False)
            bits >>= 1
            time.sleep(initdelay)

[...snip...]

class MUTInit(OBDInit):
    BAUD = 15625
    INITBYTE = 0x01
    INITBAUD = 5