Hello to all,
i am using an Arduino Yun in conjunction with a custom board based on a PIC18F25K80. The two boards are serial connected (software serial on the 32u4 side).
I have an hex file on th uSD card annd i want to read byte per byte from the 32u4 and send data to the PIC via serial.
I have done some trial but it stopped after some chars read.
I have prepared this code now (and i will try it tomorrow!):
File hex = FileSystem.open("/mnt/sda1/pic.hex", FILE_READ);
fSize = hex.size();
for (nn=0;nn < fSize; nn++) {
while (hex.available()<1){
delay(1);
wdt_reset();
}
fr[0] = hex.read();
while (hex.available()<1){
delay(1);
wdt_reset();
}
fr[1] = hex.read();
unsigned long nReadHex= strtoul(fr, NULL, 16);
sr = 0;
to = 0;
while (sr != 120 && sr != 121) {
if (mySerial.available()>0) {
sr = mySerial.read();
wdt_reset();
delay(1);
}
}
mySerial.write(nReadHex);
delay(1);
}
hex.close();
May you please explain me a little bit more about file.available() ?
As i want to read 2 bytes, i thought doing:
while (hex.available()<2) {
delay(1);
}
would help me to wait for 2 bytes available but i was waiting forever.....
Any help will be appreciated 
Regards,
Ettore