MicroHacker Forum

having a go at designing a dual CAN-BUS Arduino

Board size 53mm X 35mm pretty small

Xtal should be as close as possible to MCU.
Capacitors for Xtal should also be close to Xtal.
Put GND all round of traces from Xtal to MCU and also from Xtal to Capacitors.
Reroute the traces something like this: MCU - Capacitor - Xtal. Keep them as straight as possible and also as short as possible.

For CAN connection put a 60Ohm Resistor but also a 120Ohm Resistor as option with jumpers. This will allow you to have it in a circuit where this one is only a node, a termination node or a testing node - the other CAN devices connected don't have any resistor between CAN wires. Of course, for a testing environment even no resistor might work without problems.

I see that for power IN you used a diode to protect the circuit from wrong connection - reverse polarity; in series with your circuit. As this circuit doesn't draw too much power a 1A diode would be enough; I would go with a non SMD diode as this would allow more power through it and would disipate heat a lot more easily. For hungryer circuits the diode is in series with a fuse and in paralel with the circuit... but it must be a very fast diode and a very fast fuse.

Xtal is pretty close to mcu the board is only 53mm X 35mm it's tiny, there is jumpers with 120k resistors, I will look at the diode

Nice work Gwe89, but you should also post the schematic (sources) in order to get better support.

Go4IT wrote: ↑17 Apr 2021, 08:27 Nice work Gwe89, but you should also post the schematic (sources) in order to get better support.

Yes I think I will
I also design another for videoin option for conversmod

Maybe this is interesting
Arduino Leonardo based with 3 CANBUS interfaces

https://github.com/CANBus-Triple

Nice project! Even if i'm not 100% convinced that Arduino is the right micro for this job... a STM32 would perform much better here. But as they do it with a big ATMega32U2 i'm relaxed. This got enough ressources to handle the jobs.