Revised PCB
Last night I made some improvements to the PCB design for XulaBee, including:
- Increased most of the signal tracks to 0.5mm
- Increased the 5V supply and ground tracks to 1mm
- Fixed most angled tracks to be 45 degrees.
- Checked the circuitry to the pmod connector for the SD card
- Added circuitry for 2x sigma-delta DAC signals, including a dual op-amp to amplify the signals to line-level
- Miscellaneous other changes
Here's how it now looks:

Bottom layer copper

Top layer copper
