I read your code and it is a little difficult because you need to put more comments so that I can understand the purpose of each line of your code. Remember, that this project may take you awhile to reach perfection. You may need comments and notes in the code to remind yourself about the functions in the code.
Here are the steps that need to happen. In my case, I used a variable called mode to step through my code.
- fastinit(); Using pinmode, and HIGH and LOW
- send message = 0x81,0x12,0xF1,0x81,0x05
- wait for response 80 F1 12 03 C1 EA 8F C0
- send data request 0x80,0x12,0xF1,0x02,0x21,0x08,0xAE
- read incoming data "I believe you will receive 56 bytes back
- store results
- repeat steps 4 through 6 over and over as long as you are getting response from the ECU.
I am not sure how to properly stop communication but, I do know that there is a message that can be sent to do it.