Fix README instructions

[gabrik]

Hi,

I would first like to thank you for this very useful library.

I started using it with my simulated ECU: https://github.com/spoonieau/OBD2-ECU-Simulator but I was not getting out the right data, while Torque or other ODB apps were able to get them.

I found that the readme lacked some PID configuration for the command to parse the data.

So before I got this data:

2023-12-27 14:15:43.998 29171-30361 PID                     io.xxx.xxx                   D   : 0.0
2023-12-27 14:15:43.998 29171-30361 PID Formatted Result    io.xxx.xxx                   D  0.0 null
2023-12-27 14:15:45.103 29171-30361 PID                     io.xxx.xxx                   D   : 0.0
2023-12-27 14:15:45.103 29171-30361 PID Formatted Result    io.xxx.xxx                   D  0.0 null

Then after passing the right parameters to the PID I got ( I configured the simulator to 2000RPM):

2023-12-27 15:14:04.268 29162-30222 PID                     io.xxx.xxx                   D   : 2000.0
2023-12-27 15:14:04.268 29162-30222 PID Formatted Result    io.xxx.xxx                   D  2000.0 null
2023-12-27 15:14:05.376 29162-30222 PID                     io.xxx.xxx                   D   : 2000.0
2023-12-27 15:14:05.377 29162-30222 PID Formatted Result    io.xxx.xxx                   D  2000.0 null
2023-12-27 15:14:06.483 29162-30222 PID                     io.xxx.xxx                   D   : 2000.0

I hope this will be helpful to other developers using this library.

[gabrik]

As a side note, I guess some more commands needs to be sent into the socket to properly configure the device.

As if I open torque and then my app everything works just fine, while if I connect the ODB device and open directly my app I get a bunch of garbage data.

Any help in that direction will be more than appreciated, so that I can include it in this PR.

[barnhill]

There are some init commands that you need to send over to setup the connection.

Here is a snippet from an app I have connecting to the ELM327 device and right after this block it sends a normal request for a pid and they work.

        val MODE_AT = "AT"
		
    //set defaults
        initPid.mode = MODE_AT
        initPid.PID = "D"
        var cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Set defaults sent (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //resets the ELM327
        initPid.mode = MODE_AT
        initPid.PID = "Z"
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Reset command sent (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //extended responses off
        initPid.mode = MODE_AT
        initPid.PID = "E0"
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Extended Responses Off (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //line feeds off
        initPid.mode = MODE_AT
        initPid.PID = "L0"
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Turn Off Line Feeds (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //printing of spaces off
        initPid.mode = MODE_AT
        initPid.PID = "S0"
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Printing Spaces Off (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //headers off
        initPid.mode = MODE_AT
        initPid.PID = "H0"
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Headers Off (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //set protocol
        initPid.mode = "$MODE_AT SP"
        initPid.PID = ObdProtocols.AUTO.value.toString()
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)
        Log.d(TAG, "Select Protocol (" + initPid.mode + " " + initPid.PID + ") Received: " + cmd.rawResult)

        //set timeout for response from the ECU
        initPid.mode = "$MODE_AT ST"
        initPid.PID = Integer.toHexString(0xFF and ECU_RESPONSE_TIMEOUT)
        cmd = OBDCommand(initPid).setIgnoreResult(true).run(inputStream, outputStream)

[barnhill]

Im sure this code can be cut down from instructions

[barnhill]

You dont have to build this PID yourself.

You can request a fully built pid from the built in library this way:

val pid = PIDUtils.getPid(ObdModes.MODE_01, "OC")