Re: PCB suggestions

Posted by Seth on May 23, 2016; 12:26pm
URL: http://bluesaab-forum.90.s1.nabble.com/PCB-suggestions-tp411p414.html

I fixed the ref designators; I didn't notice they had changed, but none of the footprints are the same so nothing could get mixed up anyway.

The LED's already have silkscreen polarity indicators.

ATmega *could* have a square pin 1; The package in Eagle didn't have it and I'm not going to change it. The silkscreen indicates the direction.

Same thing with the RN52 footprint; that's how the library footprint came, I'm not going to change it.

The mini USB connector is only for RN52 firmware updates from 1.10 to 1.16. Karlis has purchased RN52 modules in the past with 1.10 (apparently old stock) which needed updating. You don't need to populate it if you don't want to (along with DFU switch, D3, R11, R12, C9).

Switching to SMD Atmega might be a pita. The chips won't come with a bootloader, so you will need a special socket just for that. I have one, but it's a $20 cable that someone will have to buy for a "one time use". I believe you can buy chips with bootloaders already programmed, but they are easily 2-3x more expensive. I'm not saying it's not possible, I'm saying it's easier for someone without a lot of experience/equipment to make a module with the through hole version instead. Plus there's just the ease of replacement if ever needed.