Intermittent interference on Gerber_PCB_LeafRange Micro v0.3C_2022-04-28.zip
PaulKennett opened this issue · comments
I'm seeing some weird errors on two boards made up using the motherboard.
The range chart shows datapoints in random spots on the graph. After searchign for program bugs my latest hunch is it's a hardware issue.
My current hypothesys is that this is due to interference between the 12V to 5V buck module and the MCP2515 CAN module. This motherboard design has the buck module mounted facing up and the CAN module facing down, directly over it.
I suspect the cheap buck converter (ie a switch mode power supply) is emitting a lot of RF noise directly at the MCP2515 chip. Also the CAN lines from the OBD2 plug run directly under the buck module.
Work-around
Un-solder the module from the motherboard (v0.3C) and have it floating away from the CAN lines and MCP2515. I don't yet know how afar away it needs to be. I've done this to a couple of prototypes and it resolved the data error issue.
Solution
I've produced a new version of the motherboard (v0.4A) which moves the buck module further away from the MCP2515.
Hopefully that'll do - but I haven't tested the new board-yet.