UART lines lack pullup resistors

Problem environment

Serial bus connections generally require pulling to VCC or GND for properly modulated waveforms.

Steps to reproduce

1. Refer to the schematic
2. Follow UART lines to connectors

Expected result

UART lines have internal or external pullup resistors.

Actual result

It's unknown if the UART lines require pullups or if this resistance is already internally provided.

Procedure

Using a oscilloscope, observe the UART waveform before and after applying resistance pulling.

Severity level

This is medium priority because while project requirements state no serial communication an implicit requirement to provide input output is present.

This report was made in response to UART corruption, resolved in bug #118. It's unlikely that hard coded pullup resistance is desired, because the MCU can probably provide the resistance selectively.