Serial Monitor not working when GPS plugged into RX pin?

Projects General Guidance
1

I've tried to search for the solution for this but I'm obviously missing something.

I was trying to get time and date off a GPS receiver using this as a guide:

https://learn.sparkfun.com/tutorials/alphanumeric-gps-wall-clock

I modified his code to elimintate the alphanumeric displays and just look at the info on the serial monitor. But absolutely nothing was printing on the serial monitor.

I unplugged the TX lead from the GPS from the RX pin (0) on my Arduino 101, re-uploaded and then it started working properly by just printing "No valid GPS serial data".

So I wrote this simple code

void setup() {

Serial.begin(9600);
while(!Serial);
Serial.println("we are beginning");
}

int counter = 0;
void loop() {

Serial.println(counter);
delay(1000);
counter++;
}

and it works when I do not have the TX lead from the GPS plugged into the RX pin on the ardiuno, but when it is plugged in, I get nothing at all on the serial monitor.

What gives?

Thanks for the help!

2

Did you connect the grounds?
What GPS and how is it powered?

3

it's this GPS:

VCC is connected to 3.3V on the Arduino.
GND is connected to GND.

And then when I connect TX of the GPS to RX of the Arduino, nothing will print to the serial monitor... I am perplexed.

4

I presume that the 101, like other Arduinos, uses pins 0 and 1 for serial I/O over USB to the serial monitor. If you connect a GPS pin to 0 or 1, it will probably block whatever is being sent to or received from the monitor.
You may have to use SoftwareSerial to read/write the GPS.

Pete

5

Thanks, I will look into SoftwareSerial and see if it solves my problem.