First I apologize for asking a seemingly non-Keil related question. I have 2 evaluation boards (STM32 Olimex and another, home-made). Their grounds are connected, supply is separate. Both are connected to a TCP/IP network. I am sending a signal (about 56 KHz) from one to the other via a wire, and the decoding of that works, but not always: automated tests that verify the software fail (while manual tests work...) after programming an board chip on one of the boards plus an FPGA. When I say fail I mean that the target board does not send out a reply via the network indicating it decoded the 56 KHz successfully. I have noticed that I can rectify the situation by either connecting a probe to the signal pin at the receiver and the ground it to the common ground, or connect a ST-Link V2 to the Olimex board. This begs for to be grounding/parasite capacitance problem, but how can I determine that let along solve it? Thanks in advance
Does not sound like such a low frequency / short wire can contribute a lot to wire capacitance issues.