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Topic: error: sim900 doesn't answer. check power and serial pins in gsm.cpp status=idle (Read 151 times) previous topic - next topic

I bought the shield with the SIM908 module but I can not get it work.
I've been working with USB power, and the LED doesn't blik. I have tried with an external power supply, and then it blinks (7.5V - 150 mA).
With both of them I get the following error code:

GSM Shield testing.
DB:NO RESP
DB:NO RESP
DB:NO RESP
Trying to force the baud-rate to 9600
ERROR: SIM900 doesn't answer. Check power and serial pins in GSM.cpp
status=IDLE

I'm working with:
- Arduino MEGA 2560
- Jumpers are set on serial software
Please, can you help me??????

dannable

Which shield, what code?

Do you have a CP2102 USB to UART bridge - it would be useful to test the shield?
Beginners guide to using the Seeedstudio SIM900 GPRS/GSM Shield

#include <SoftwareSerial.h>
char inchar; // Will hold the incoming character from the GSM shield
SoftwareSerial SIM900(7, 8);
 
int led1 = 10;
int led2 = 11;
int led3 = 12;
int led4 = 13;
 
void setup()
{
  Serial.begin(19200);
  // set up the digital pins to control
  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  digitalWrite(led1, LOW);
  digitalWrite(led2, LOW);
  digitalWrite(led3, LOW);
  digitalWrite(led4, LOW);
 
  // wake up the GSM shield
  SIM900power();
  SIM900.begin(19200);
  delay(20000);  // give time to log on to network.
  SIM900.print("AT+CMGF=1\r");  // set SMS mode to text
  delay(100);
  SIM900.print("AT+CNMI=2,2,0,0,0\r");
  // blurt out contents of new SMS upon receipt to the GSM shield's serial out
  delay(100);
  Serial.println("Ready...");
}
 
void SIM900power()
// software equivalent of pressing the GSM shield "power" button
{
  digitalWrite(9, HIGH);
  delay(1000);
  digitalWrite(9, LOW);
  delay(7000);
}
 
void loop()
{
  //If a character comes in from the cellular module...
  if(SIM900.available() >0)
  {
    inchar=SIM900.read();
    if (inchar=='#')
    {
      delay(10);
 
      inchar=SIM900.read();
      if (inchar=='a')
      {
        delay(10);
        inchar=SIM900.read();
        if (inchar=='0')
        {
          digitalWrite(led1, LOW);
        }
        else if (inchar=='1')
        {
          digitalWrite(led1, HIGH);
        }
        delay(10);
        inchar=SIM900.read();
        if (inchar=='b')
        {
          inchar=SIM900.read();
          if (inchar=='0')
          {
            digitalWrite(led2, LOW);
          }
          else if (inchar=='1')
          {
            digitalWrite(led2, HIGH);
          }
          delay(10);
          inchar=SIM900.read();
          if (inchar=='c')
          {
            inchar=SIM900.read();
            if (inchar=='0')
            {
              digitalWrite(led3, LOW);
            }
            else if (inchar=='1')
            {
              digitalWrite(led3, HIGH);
            }
            delay(10);
            inchar=SIM900.read();
            if (inchar=='d')
            {
              delay(10);
              inchar=SIM900.read();
              if (inchar=='0')
              {
                digitalWrite(led4, LOW);
              }
              else if (inchar=='1')
              {
                digitalWrite(led4, HIGH);
              }
              delay(10);
            }
          }
          SIM900.println("AT+CMGD=1,4"); // delete all SMS
        }
      }
    }
  }
}

dannable

Which shield?

The example sketch you have listed uses pins 7 and smiley face to communicate with the shield. I'm assuming it should be pin 8. (That's why you use code tags)

Does your shield communicate using those pins?
Beginners guide to using the Seeedstudio SIM900 GPRS/GSM Shield


dannable

So what was the reference to SIM908 earlier?

And I have four different SIM900 based shields. Which one have you got? A link please.
Beginners guide to using the Seeedstudio SIM900 GPRS/GSM Shield

http://jualarduinomurah.com/jual-sim900-quad-band-gsm-gprs-shield-murah/

dannable

The link in my signature shows you how to test and use that shield.
Beginners guide to using the Seeedstudio SIM900 GPRS/GSM Shield


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