Hello,
I bought a CMOD A7 to build this nice project by René Ceballos (@rgc) https://www.futur3soundz.com/xfm2
I built an interface too, with an arduino nano. When I first connected the TX pin from the arduino to the RX pin of the CMOD, unfortunately I forgot to add a voltage divider, so for about 10 seconds 4.8-4.9 volts from the arduino went directly to the RX pin of the CMOD (same for the TX pin, the same voltage arrived from the arduino RX). I saw that in the reference manual the maximum allowed voltage for I/O pins is 3.7V so I'm afraid I burned the two pins (26 and 27) because in the manual is clearly said that the pins are connected directly without resistors or any type of protection.
Now that I'm using the tx pin with the voltage divider, the A7 is giving no signs of response to incoming serial messages from the pins, but I get response (and flashing LED) when using the USB-UART.
The strange thing is that the two pins seems to work because the voltage on pins 26 and 27 is 3.3V, I'm thinking that if they are burned then they would have 0V (but I'm not sure).
Unfortunately, I cannot swap the pins to other pins in the board because I don't have any HDL source, but only the .bin and .bit files.
Is there a way to check if the two pins are still alive and if they respond to serial messages when set them as UART receiver/transmitter?
Thanks in advance