Yesterday I've received my beautiful OSHPark boards and started to solder with the help of the stencil I got from OSHstencil.com. Sadly I've noticed that the crystal I got is the wrong size and I need to touch up some connections (pins are shorted at the power muxing chip etc.) I also need to solder the front side, meaning buttons and RGB LEDs.
Some thoughts about the parts used led me to change some footprints or completely swap parts. Already a lot of work to do again, but hopefully this way production might be easier and is not dependent on getting parts on ebay for cheap, but having them available on large amounts on digikey and mouser etc.
- To have almost every part available on mouser meant to switch the CH340G to the CP2102N, this also means no crystal footprint to worry anymore
- the LDO AMS1117 has not the lowest dropout voltage you can get for a board like this, so I switched to the AP2112 like adafruit uses on their huzza boards
- I've also changed the footprint of every cap and resistor to use 0603 parts
- There are still some footprints to change, like the SD card adapter
- probably the PCF8574 that scans then buttons (there are QFN and BGA footprints that are missing in my library)
- the I2C port / grove connector was 1.5mm by accident, so I also had to redesign that
- I've took out the complete RGB section with resistors, LEDs and transistors and replaced them with 2mm APA102 LEDs, will make rerouting a lot easier
- the footprint for the USB micro socket also doesn't have the holes, so I had to use the USB mini port