Re: V5 & AMP on one board

Posted by sbt on Feb 24, 2017; 2:14am
URL: http://bluesaab-forum.90.s1.nabble.com/V5-AMP-on-one-board-tp972p1009.html

Karlis wrote

With "automotive" I as thinking of a two-in-one solution for uC and CAN controller. So there's only one chip that does both. We could retire MCP2515 in that case and save tons of space by doing so.

I would agree that by definition it means better tolerances to heat, humidity, vibrations and whatnot, but my idea was more of a 2:1 solution. :)

Karlis, sure, but I was only addressing the comment with respect to the price differences amongst ATMEGA328Ps. But I note that the 2 in 1 μCs I've seen seem to have higher pin counts and greater footprints (and also smaller legs for soldering). I'm not sure how much real-estate you'd save.

Not trying to be a negative nelly, but I think there's more benefit in focusing on the software for the current platform; there's a development and support cost from forks in the code if the μC is changed, in exchange for no significant functional win from changing it that I can see. The main benefit of returning to a single PCB has been achieved, thanks to Antoine and Seth.

It's yet to be established whether we can master the track info functions via the current serial connection to the RN52 and the other wrinkles with the SID display functions. I'd suggest holding off further hardware changes unless and until an actual issue is found that software can't solve. There's a possibility that adding a second hardware UART would help, but actually I'd expect just a pin re-assignment on the ATMEGA328P so we could do hardware serial is all that would be required, if anything.

I've excluded software updates via Bluetooth from this as I can't see any significant PCB wins from adding this support; if you insist the FTDI and UART headers are needed for debugging/recovery etc, we'd never be able to remove them anyway. I doubt BT firmware updates for the μC will be possible in any case, and probably not worth the hassle if there are only 2 or 3 more updates to come before the BlueSaab software is functionally complete. There's also the issue of delivery via app stores, security, signing, etc.

That said, I still think the FTDI 6-pin header is redundant, now that the UPLOAD port is available. What can you do with FTDI you can't do with FTDI via USB?

Cheers,
Sam.