Using the C94 M8P ublox eval kit which comprises a base station and rover. The base station remains static and is given plenty of time to get an accurate fix. The rover then communicates with the base station via a radio link and corrections are sent to the rover to get a more accurate fix as it moves around. So far I have got 10cm deviation in one hour, which is a pretty good starting point. Now trying to get the rover to talk to an Arduino due:The Arduino Due Rx1 connects to pin 10 of the Ublox M8P on J8. The numbering on J8 is a bit weird - think 'snakes and ladders' rather than 'circular'. Eventually I got some data received using this simple code:

void setup() {
  // initialize both serial ports:
  Serial.begin(9600);
  Serial1.begin(9600);
  Serial.println("Ready to test");
}

void loop() {
  // read from port 1, send to port 0:
  if (Serial1.available()) {
    int inByte = Serial1.read();
    Serial.write(inByte);
  }
}

The code prints out everything received on Tx1 to Rx0 and I got this slightly garbled result:Looks like the radio transmit interferes with some of the data, but I'm guessing I can filter this out through character analysis in strings.