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Topic: shield GSM GPS SIM808 UNO - Serial communication problem - jumpers (Read 623 times) previous topic - next topic



Arduino novice user I try to make a moto alarm based on SIM808 shield and arduino UNO.

I buy this kit SIM808 kit : https://www.aliexpress.com/snapshot/0.html?orderId=82650808744830&productId=32271825455

The shield is well plugged on arduino UNO

I tried different software librairies first to communicate by software serial
such as :

#include <SoftwareSerial.h>

SoftwareSerial GSMSerial(7, 8);

void setup()
GSMSerial.begin(19200);               // the GPRS/GSM baud rate   
Serial.begin(19200);                 // the GPRS/GSM baud rate   

void loop()


else  if(GSMSerial.available())


or other basic soft with "specific" librairy :

#include <Arduino.h>
#include "SoftwareSerial.h"
#include "ElementzGSM.h"

SoftwareSerial myserialOut(6, 7);
ElementzGSMshield GSM(&myserialOut);

void setup(/* arguments */) {
  /* code */

  GSM.SendAT("AT", "OK", 1000, 2);
  GSM.SendAT("AT+CREG?", "+CREG: 0,0", 1000, 2);

void loop(/* arguments */) {


My soft is ok and compiles well but I did not succeed to establish serial communication :
serie monitor does not return any data.

First I thank it was due to supply power (UNO card current limit) of the shield then
I supplied with external 5V alimentation but without success...

My main question is about jumpers configuration. I did not find accurate jumpers position
for software serial conf for my shield (some shield have 6 PIN but mine have 8 PIN)

Has anybody used this shied or can find the jumper position by deduction ?
Or has any other idea to know why it does not work. ?

Cf attached file to see my jumpers conf based on other shield information and photo
on the web...

Thanks for your answers!


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