Arduino with SIM808 EVB-v3.2 not working

Projects Programming
1

Hi everyone,

I bought SIM808EVB-v3.2 module (https://fr.aliexpress.com/item/SIM808-instead-of-SIM908-module-GSM-GPRS-GPS-Development-Board-IPX-SMA-with-GPS-Antenna-for/32647682188.html?spm=2114.13010608.0.0.WrgmgQ) and I'm trying to use it with the Arduino UNO.

I've inserted my simcard into the SIM808 and I've connected the following :

TXD => Pin 0 on Arduino
RXD => Pin 1 on Arduino
GND => GND
V_IN => 5V on Arduino

Here is a picture of the wiring : https://www.hostingpics.net/viewer.php?id=552320IMG3367.jpg

After that, I've powered my Arduino and my SIM808 module.

I've also downloaded the SIMCom library from GitHub - itead/ITEADLIB_Arduino_SIMCom: GSM GPRS GPS Bluetooth for SIM800/808/900/908 Shield Library and, in the file GSM.cpp, I've changed :

#define _GSM_TXPIN_ 2
#define _GSM_RXPIN_ 3

to :

#define _GSM_TXPIN_ 1
#define _GSM_RXPIN_ 0

Then, I've uploaded the example of simple GSM/GPRS read to the Arduino :

#include "SIM900.h"
#include <SoftwareSerial.h>
//#include "inetGSM.h"
//#include "sms.h"
//#include "call.h"

//To change pins for Software Serial, use the two lines in GSM.cpp.

//GSM Shield for Arduino
//www.open-electronics.org
//this code is based on the example of Arduino Labs.

//Simple sketch to communicate with SIM900 through AT commands.

//InetGSM inet;
//CallGSM call;
//SMSGSM sms;

int numdata;
char inSerial[40];
int i=0;


void setup()
{
     //Serial connection.
     Serial.begin(9600);
     Serial.println("GSM Shield testing.");
     //Start configuration of shield with baudrate.
     //For http uses is raccomanded to use 4800 or slower.
     if (gsm.begin(9600))
          Serial.println("\nstatus=READY");
     else Serial.println("\nstatus=IDLE");
};

void loop()
{
     //Read for new byte on serial hardware,
     //and write them on NewSoftSerial.
     serialhwread();
     //Read for new byte on NewSoftSerial.
     serialswread();
};

void serialhwread()
{
     i=0;
     if (Serial.available() > 0) {
          while (Serial.available() > 0) {
               inSerial=(Serial.read());
               delay(10);
               i++;
          }

          inSerial='\0';
          if(!strcmp(inSerial,"/END")) {
               Serial.println("_");
               inSerial[0]=0x1a;
               inSerial[1]='\0';
               gsm.SimpleWriteln(inSerial);
          }
          //Send a saved AT command using serial port.
          if(!strcmp(inSerial,"TEST")) {
               Serial.println("SIGNAL QUALITY");
               gsm.SimpleWriteln("AT+CSQ");
          } else {
               Serial.println(inSerial);
               gsm.SimpleWriteln(inSerial);
          }
          inSerial[0]='\0';
     }
}

void serialswread()
{
     gsm.SimpleRead();
}
}

Unfortunately, after the upload, I get a "DB:NO RESP" error message from the IDE serial console.

GSM Shield testing.
ATT: OK
RIC:
Shield testing

ATT: OK
RIC:
Shield testing

DB:ELSE
DB:NO RESP
DB:NO RESP
DB:NO RESP
Trying to force the baud-rate to 9600

1200
2400
4800
9600
19200
38400
57600
115200
ERROR: SIM900 doesn't answer. Check power and serial pins in GSM.cpp

status=IDLE

I've tried to change values in the file GSM.cpp to :

#define _GSM_TXPIN_ 0
#define _GSM_RXPIN_ 1

but it still not work.

So, can someone please help me ?

Thank you :slight_smile:

2

Like everyone else, you can NOT do SoftwareSerial on the hardware serial pins while also using the pins for hardware serial.

3

Hi PaulS,

In fact, you're right, SoftwareSerial can't be used on the hardware serial pins while also using the pins for hardware serial !

This changes made my SIM808 GPS code work :

TXD => Pin 0 Pin 2 on Arduino
RXD => Pin 1 Pin 3 on Arduino
GND => GND
V_IN => 5V on Arduino

And here is my new GPS code that work now :

#include <SoftwareSerial.h>
#define DEBUG true
SoftwareSerial mySerial(2,3); 
        
void setup(){
  Serial.begin(9600);
  mySerial.begin(9600); 
  getgps();
}

void loop(){
   sendData( "AT+CGNSINF",1000,DEBUG);   
}

void getgps(void){
   sendData( "AT+CGNSPWR=1",1000,DEBUG); 
   sendData( "AT+CGPSINF=0",1000,DEBUG); 
}

void sendData(String command, const int timeout, boolean debug){
    String response = "";    
    mySerial.println(command); 
    delay(5);
    if(debug){
    long int time = millis();   
    while( (time+timeout) > millis()){
      while(mySerial.available()){       
        response += char(mySerial.read());
      }  
    }    
      Serial.print(response);
    }    
}

So now, I've an other problem with my SIM808 GSM code.

Serial.println("AT");
delay(50);
Serial.println("AT+CMGF=1");
delay(50);
Serial.println("AT+CMEE=2");
delay(50);
Serial.println("AT+CMGS=\"+336xxxxxxxx\"");
delay(50);
Serial.println("HELLO WORLD");
delay(50);
Serial.println((char)26);

Indeed, I've inserted my simcard in the SIM808 and when I try to send an SMS with it, some AT commands return errors :

AT
OK

AT+CMGF=1
CME ERROR: 10 (SIM not inserted)

AT+CMEE=2
OK

AT+CMGS="+336xxxxxxxx"
The error is like 'bad value' or something like that

Potentially, I have a clue thinking that my SIM808 module is not properly powered because only V_IN is wired to +5V on Arduino and there is an other space for li-ion battery 3.5V-4V which is not wired (see https://www.hostingpics.net/viewer.php?id=552320IMG3367.jpg)

So, do you think that this additional battery is needed to power the module and made my SIM808 recognize my simcard ?

Thanks :wink:

4

check out page 22 and also,does your sim card have 4 digit pin on it? have you removed it?

5

Page 22 doesn't tell that an additional Li-ion battery is necessary to power the SIM808 module.

My question is : Is a battery required in addition to the 5v pin connection to the arduino ?

Yes, my simcard have 4 digit pin on it but, when I try to enter it with "AT+CPIN", an error message is raised telling me that "sim is not inserted".

That's why I think that I've a problem with power supply ...