On the CAN BUS Shield there is a jumper labeled TERM.
Does that mean that the Endpoint Terminating Resistor is enabled by default ?
I’ve looked around on the OpenMV Docs and haven’t really found much info about this shield, like how to wire it, etc.
Does TX=H and RX=L WRT the pin names I’ve seen on other CAN devices ?
To be clear, I want to use this an a CAN node and not OBD-II.
I’m going to be connecting it to a Raspi CAN HAT like this one here:
Also, the example link on the product page is broken:
https://github.com/openmv/openmv/blob/master/scripts/examples/02-Board-Control/can.py
Thanks!
Espressobot
Ah, thanks for letting me know. the example moved. Fixing now.
So, CAN won’t work with RS485. So, you can’t use it with that shield.
As for TX/RX… those are from the CPU… which get converted to CAN signals on the RS232 connector.
The RS232 connector is wired for standard DB-9 CAN or if you want you can change it to the DB-9 ODBII standard.
Finally, regarding the terminating resistor…It’s by default.
Please note, the schematic is on the product page which really explains it all.
But, before looking at that. You should google how CAN/RS485 work and how they are different. You asked several questions in a row that show you’re not read up on all of this. You can avoid some electrical issues upfront if you do some research about how the protocol works and what connectors folks like to use.
Like, if you have plugged these two shields into each other one would likely break.