racediffer

README

racediffer

This is a tool intended to work with RaceCapture's CAN Bus Data Logger. It eliminates the need for tools like Hyperterminal and Minicom and directly decodes the output of the default RaceCapture script, logging to a *.jsonl file.

It also allows you to hit the space bar to emit a numbered event to the log file. This is particularly handy when you're trying to reverse engineer the CAN bus by following a script and demarcating specific events that happen in the car, for example:

* Get in the car and turn on accessories.  Wait 30 seconds.
* EVENT 1
* Throttle up
* EVENT 2
* EVENT 3
* Throttle down
* EVENT 4

When reverse engineering, you could now compare IDs looking for ones that are flat before EVENT 1, rising between EVENT 1 and EVENT 2, decreasing between EVENT 3 and EVENT 4.

The only required flag specifies where to write the output, as the terminal UI is written to STDOUT and log messages are written to STDERR:

* --output: path name to write *.jsonl file

You can capture output directly from the serial port:

* --device: the path to the serial device (default /dev/cu.usbmodem00000000011C1)
* --baud: the baud of the serial device (default 115200)

If you captured a log from a RaceCapture previously, you can replay it instead of connecting through the serial port, and control the rate that the log is read:

* --simulate: path name to read a previously captured log from RaceCapture
* --simulate_rate: the rate at which the simulated rate limited reader bucket refills (default 8192)
* --simulate_capacity: the capacity of the simulated rate limited reader bucket (default 8192)