Perhaps one important thing to note is this. When performing Serial.println("") from the YUN while running the below sketch on the pro mini I do get values appearing in the pro mini serial terminal.
So, I believe the data is being received. Of course this code is not correct for what I want to achieve, but though I'd pass this fact along.
Thank you
void loop() {
// put your main code here, to run repeatedly:
if (Serial.available() > 0)
Serial.println(Serial.read());
}
Result in terminal. For example.
248
240
248
230
252
252
248
248
240
240
240
240
255
30
224
255
224
255
120
240
12
128
4
192
224
224
255
240
248
248
231
147
248
224
254
255
252
254
254