Hello,
I would like to use the current monitoring capability of the VEX PDP using the TX1 (preferably) or any microcontroller with a CAN port. Is this possible, and could you direct me to some useful documentation regarding that?
Thanks:D
I believe the ctre hero can do that.
The short version is that CAN Bus is a communications standard, like RS-232 or TCI/IP. CAN messages are readable by most any CAN-capable device, you just need to know the details of that particular CAN message (which is surely in the specs somewhere, or can be had from the supplier).
Time for some phone calls…
The TX1 does have a CAN interface but it’s not broken out on the Nvidia Carrier… it is available on the Auvidea J120 carrier but it’s an exercise for you to connect to it and program something to talk over it. As for talking to the PDP… it should be a matter of formatting the messages correctly and then referencing the CTRE documentation for the PDP.
Would you mind pointing me to the protocol documentation for the PDP? It seems like a black box to me.
You’re right! At least I can’t find it in the user guide here: http://www.ctr-electronics.com/PDP%20User’s%20Guide.pdf
I’m mobile at the moment but I’m wondering if there are any examples in the CTRE github. Perhaps Omar can chime in and correct me with where to find it.
Edit: This seems to be the relevant bits from WPIlib: https://github.com/wpilibsuite/allwpilib/tree/master/hal/include/ctre
It’s not yet available, but keep an eye on the xCAN being developed by some folks at the Nullspace Labs hackerspace. It’s STM32-based, and it has twin CAN buses, USB, and a microSD slot. Charlie intends it to be a platform for the CAN hacking tools he’s developed for tweaking his race car, there’s no reason it can’t be made very useful for our purposes.
This is the Crowd Supply page for it, and the base page at NullSpace.
The hardware was first developed as the badge for this year’s Layer One conference in LA. It showed a slideshow of sponsor logos, or if you connected a USB gamepad and inserted an SD card full of ROMS, it ran an NES emulator.
The Subversion archive for the source code may not be updated yet, but the emulator/slideshow firmware that ran at the conference is on the ST mbed site
Will most CAN-reading micros ignore the heartbeat/security token passed on the FRC CAN Bus? I have heard with it screwing up CAN interpretation with some logic analyzers (particularly the Saleae logic analyzers). My gut instinct says they would have to be able to. It didn’t seem like there was anything special about the CAN chip on the Jaguar.
I think you can download a non FRC firmware version off the ctre website that doesn’t have the token.