EM-408 - Arduino UNO

Hi there,

I did not find any proper tutorial with this. And additionally there is a lot of misguided documentation on the web.
Thats why I am documenting my little finding hoping to spare you guys the hours of trying.

Datasheet of the EM-408 is here: http://geoffg.net/Downloads/EM408/EM408_User_Manual.pdf

And here the code:

#include <SoftwareSerial.h>

SoftwareSerial gps(3,4); 

void setup() {
  pinMode(2, OUTPUT);
  pinMode(3, INPUT); 
  digitalWrite(2, HIGH);
  digitalWrite(3, LOW);

  //gps.println("hi, are u there?");

void loop() {

  if (gps.available())

Here some points:

  • En/Disable has to be HIGH with 5V
  • TX: Arduino can readDigital with 3.3V as HIGH. I tested it with 2.0V and a pin reads it as HIGH.
  • RX: can be floating around.

If you have some remarks pls let me know.



I don't think the gps module will respond to a bunch of characters, as it only deals with gps functions. You have to give it requests for it to respond back with, these requests are preprogrammed into the gps module. When you put gps.print("insert text here"); the arduino sends it a bunch of shenanigans that it doesn't know what to make of it.

I corrected the script.

Good Night,
Please , I wonder whether it was successful with GPS EM- 408 module and the Arduino ?
I used the code and the layout you entered the forum and so was strange characters meaningless .
The GPS pin 3 is not connected in any Arduino door ?
I thank you .
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