Closed alexisvl closed 7 years ago
Wow, awesome job! Looks a lot better.
I had little knowledge about these things until now -- thanks a lot for contributing.
If I find anyone trying to do emission tests, I'll try to make sure they use this revision :)
If you (or anyone else) orders new revision boards from dirtyPCBs or similar fab, please let me know the store link so I can put it on the wiki.
@cpavlina @conorpp - Out of curiosity, should there be pull-up resistors added for the I2C bus connection between the micro and the encryption coprocessor?
Ideally yes, but as long as it's working... I assume it's using the resistors internal to the microcontroller, which are probably (NB: didn't read the datasheet) on the order of 50k. That'll give pretty long rise times, but if the bus is running at a low enough clock rate it shouldn't matter, I2C is pretty tolerant. If there ever was data corruption, I'd be looking there, but things seem to work fine.
Yes, internal weak pull ups in the microcontroller are used. They didn't seem to be an issue as I never ran into integrity errors during development.
Hey, thanks for this nice project! Actually saw this mentioned on Twitter and bought a couple right away :) Thought I'd have a play around with the sources.
I noticed a few things worth improving on the PCB, so I thought I'd submit a pull request. This commit fully reroutes the PCB, changing:
I haven't moved the programming points, so nothing changes for test/flash. I did move the decoupling capacitors - if that's an inconvenience for assembly, I can put them back where they were and keep the rest of the changes, but for EMC purposes they should really go where I moved them to.