I need to know which pins are I/Os that I can use as general purpose without interfering with other functions.
(I cannot open the Sch or trace files with my ExpressPCB)
My understanding is:
- All Pxx pins can be used as GPIO
- P31 and P30 are those used by the USB and need to be free if I wish to send/receive serial messages to the device.
- P29 and P28 can be used as GPIO if I do not use I2C modules.
Am I right on all of these?