Is there a guide for adding custom PIDs to the One+?

[dsjstc]

I've bought a One+ unit to help with my Master's research project. I need to have the DataLogger software log fuel tank level from a 2010 (Gen III) Prius, basically just in order to detect fillups. From the Torque Pro forums, I understand that this is PID 29, MODE 21.

I can't figure out how to log the custom PID. I have not had much luck searching these forums -- they're choked with spam, and most of my search keywords are rejected for being "too common". Apparently other people are also having trouble with this.

Basically, all I've found is [this post](viewtopic.php?f=11&t=1873&p=5322#p5322) -- but the links are broken, and it is specific to the One unit, not a One+. It also doesn't seem to address a PID with a mode.

**Questions:**

1. Is there a guide somewhere?

2. For the One+, I'm guessing I should be modifying library files FreematicsBase.h, FreematicsPlus.cpp, and datalogger.ino. Yes?

3. For the .h, how what will my #define look like for Mode 21, PID 29?

4. For the .cpp, the file contains no switch. Which function needs modifying to use the new PID?

5. For the .ino, which array? Is it PID_POLLING_INFO obdData[]?