Set up an Arduino Cellular Shield SM5100B

Question

I'm trying to set up an Arduino Cellular Shield SM5100B to send SMS.

My setup is:

• Arduino UNO R2
• SM5100B
• "Movistar" SIM Card (Chile)

I've uploaded a code similar to the one described here, but when communication is supposed to star it cannot find a network. I suspect the problem is I haven't setup correctly the GSM band. But when I issue the command (AT+SBAND=7, same as in the US), it doesn't respond. How can I check in what band I'm on? And change the band?

• sachleen: How are you issuing the command to it? Do you have a new line after the command? Maybe it needs CR+LF. You can tweak those options in your serial terminal program.

Answer 1

/*
 Band Management
 This sketch, for the Arduino GSM shield, checks the band
 currently configured in the modem and allows you to change 
 it.
 Please check http://www.worldtimezone.com/gsm.html
 Usual configurations:
 Europe, Africa, Middle East: E-GSM(900)+DCS(1800)
 USA, Canada, South America: GSM(850)+PCS(1900)
 Mexico: PCS(1900)
 Brazil: GSM(850)+E-GSM(900)+DCS(1800)+PCS(1900)
 Circuit:
 * GSM shield 
 created 12 June 2012
 by Javier Zorzano, Scott Fitzgerald
 This example is in the public domain.
 */
 // libraries
 #include <GSM.h>
 // initialize the library instance
 GSMBand band;
 void setup()
 {
 // initialize serial communications and wait for port to open:
 Serial.begin(9600);
 while (!Serial) {
 ; // wait for serial port to connect. Needed for Leonardo only
 }
 // Beginning the band manager restarts the modem
 Serial.println("Restarting modem...");
 band.begin();
 Serial.println("Modem restarted.");
 };
 void loop()
 {
 // Get current band 
 String bandName = band.getBand(); // Get and print band name
 Serial.print("Current band:");
 Serial.println(bandName);
 Serial.println("Want to change the band you’re on?");
 String newBandName;
 newBandName = askUser();
 // Tell the user what we are about to do...
 Serial.print("\nConfiguring band "); 
 Serial.println(newBandName); 
 // Change the band 
 boolean operationSuccess; 
 operationSuccess = band.setBand(newBandName); 
 // Tell the user if the operation was OK 
 if(operationSuccess)
 { 
 Serial.println("Success");
 } 
 else
 { 
 Serial.println("Error while changing band");
 } 
 if(operationSuccess)
 { 
 while(true); 
 } 
 }
 // This function offers the user different options
 // through the Serial interface
 // The user selects one
 String askUser()
 {
 String newBand; 
 Serial.println("Select band:"); 
 // Print the different options 
 Serial.println("1 : E-GSM(900)"); 
 Serial.println("2 : DCS(1800)"); 
 Serial.println("3 : PCS(1900)"); 
 Serial.println("4 : E-GSM(900)+DCS(1800) ex: Europe"); 
 Serial.println("5 : GSM(850)+PCS(1900) Ex: USA, South Am."); 
 Serial.println("6 : GSM(850)+E-GSM(900)+DCS(1800)+PCS(1900)"); 
 // Empty the incoming buffer 
 while(Serial.available()) 
 Serial.read(); 
 // Wait for an answer, just look at the first character 
 while(!Serial.available()); 
 char c= Serial.read(); 
 if(c=='1')
 newBand=GSM_MODE_EGSM; 
 else if(c=='2')
 newBand=GSM_MODE_DCS; 
 else if(c=='3')
 newBand=GSM_MODE_PCS; 
 else if(c=='4')
 newBand=GSM_MODE_EGSM_DCS; 
 else if(c=='5')
 newBand=GSM_MODE_GSM850_PCS; 
 else if(c=='6')
 newBand=GSM_MODE_GSM850_EGSM_DCS_PCS; 
 else
 newBand="GSM_MODE_UNDEFINED";
 return newBand;
 }