Raspberry PI Uart: pi to pi communication (B+, B2, CMIO)

Question

Good day

I am currently setting up UART communications for two Raspi's using wiring Pi's uart library. I have three Raspberry Pi's (B+, Compute Module IO board, B2). I have been able to make communication between B+ and B2 but so far have been unsuccessful with the CMIO/Compute Module IO board. Is there a special way to set up UART for the CMIO board? The uart communication was intended between the B+ and the CMIO, the B2 is just used for debugging.

What I have tried are the following:

1. use raspi-config to disable Serial
2. use stty -F/dev/ttyAMA0 100000#
3. checked that the Tx and Rx are inter connected (Tx->Rx and Rx->Tx)

I remember editing the dtblob for the CMIO to reroute the I2C, is there a required way similar for UART set-up?

I have been so stuck with this problem. Your help would be very appreciated.

PS, I cannot use the ethernet port as the CMIO does not have one :)

Answer 1

It turns out, in the dt-blob.dts file that I have previously modified to accomodate two pi cameras that the UART was disabled :)