Now the baud rate is correct:
while(true) {
int serialInput;
Serial.begin(4800);
serialInput = Serial.read();
Serial.begin(9600);
Serial.println("Seria input was:");
Serial.println(serialInput);
}
But the output is still always -1
I measured the voltage the GPS receives: its 4,75
Next step will be to hook it up to the Basic Stamp and make it work there, and then transition the RX and TX line to the Arduino, but leave it power fed from the Basic Stamp, to rule out power supply being an issue. But that'll be tomorrow.. I have to go to sleep now.