Hi
In the schematic in:
CAN Bus Guide — ODrive Documentation 0.6.11 documentation
It it shown that CAN-gnd should not be connected to common ground.
However it seems that is the case at the picture in:
Controlling ODrive from an Arduino via CAN — ODrive Documentation 0.6.11 documentation
What is correct?
I find the setup rather sensitive and suddently looses its calibration etc.
Hi! On the ODrive Micro and S1, CAN is referenced to the ODrive’s DC-, and the CAN connectors are just used for a convenient daisy-chain (the CAN GND is internally not connected, only passed between the connectors). On the ODrive Pro, CAN is referenced to CAN_GND (which must be connected to the system DC- at some point). Typically, you want to star logic and power grounds at a single location. In the Arduino docs, the passthrough CAN_GND is used as an easy way to get the Arduino on the same ground domain as the S1 – another option would be to just run a wire from Arduino GND to the S1 DC-, or preferably to do so near your power supply / battery / power distribution block. Note that it does show to connect grounds in the CAN bus guide:
I find the setup rather sensitive and suddently looses its calibration etc.
Hmm, that’s quite interesting. Can you share more? Which ODrive, encoder, motor, etc? That generally sounds more like an encoder issue.
Hi
Thanks.
I fully understand how to connect gnd, but my point is that there is inconsistency between the photo and the description. On the photo the CAN_GND is connected to DC- event though the description says that this is done internally on the S1 board. This is just to avoid more gnd-loops.
After moving from ESP32 and UART to Teensy and CAN it seems that the setup is more stable.
Fully understood! Our CAN docs/guide aren’t super great at the moment, our biggest TODO is to improve all that, which I hope to do really soon!
