Content originally posted in LPCWare by nxp_apps on Fri Jun 20 12:21:41 MST 2014
Hi,
The problem could be related to the potentiometer on the LPC812 LPCXpresso board where it can add an offset to the signal on the PIO0_0 (RX) pin, which will cause the communication to fail if the pot is set either to high, or to low. If you keep it in the middle, it should work. Or better, you can remove the R55 resistor or POT if you don’t plan on using the comparator input on the LPC800.
Thanks.
nxp_support