Hello, I have this specific SIM900a module but it seems that I am not connecting. Using a sim card capable of 2g-4g. Connected rx SIM900 to pin 3 and tx SIM900 to pin2. been looking round the internet for solutions
I have used the code provided by arduino site itself here
// import the GSM library
#include <GSM.h>
// PIN Number
#define PINNUMBER ""
// initialize the library instance
GSM gsmAccess(true); // include a 'true' parameter for debug enabled
GSMScanner scannerNetworks;
GSMModem modemTest;
// Save data variables
String IMEI = "";
// serial monitor result messages
String errortext = "ERROR";
void setup()
{
// initialize serial communications
Serial.begin(9600);
Serial.println("GSM networks scanner");
scannerNetworks.begin();
// connection state
boolean notConnected = true;
// Start GSM shield
// If your SIM has PIN, pass it as a parameter of begin() in quotes
while(notConnected)
{
if(gsmAccess.begin(PINNUMBER)==GSM_READY)
notConnected = false;
else
{
Serial.println("Not connected");
delay(1000);
}
}
// get modem parameters
// IMEI, modem unique identifier
Serial.print("Modem IMEI: ");
IMEI = modemTest.getIMEI();
IMEI.replace("\n","");
if(IMEI != NULL)
Serial.println(IMEI);
// currently connected carrier
Serial.print("Current carrier: ");
Serial.println(scannerNetworks.getCurrentCarrier());
// returns strength and ber
// signal strength in 0-31 scale. 31 means power > 51dBm
// BER is the Bit Error Rate. 0-7 scale. 99=not detectable
Serial.print("Signal Strength: ");
Serial.print(scannerNetworks.getSignalStrength());
Serial.println(" [0-31]");
}
void loop()
{
// scan for existing networks, displays a list of networks
Serial.println("Scanning available networks. May take some seconds.");
Serial.println(scannerNetworks.readNetworks());
// currently connected carrier
Serial.print("Current carrier: ");
Serial.println(scannerNetworks.getCurrentCarrier());
// returns strength and ber
// signal strength in 0-31 scale. 31 means power > 51dBm
// BER is the Bit Error Rate. 0-7 scale. 99=not detectable
Serial.print("Signal Strength: ");
Serial.print(scannerNetworks.getSignalStrength());
Serial.println(" [0-31]");
}
you need to connect GND as well and possibly other pins (any reset?)
you need to power the module appropriately as well. (2 amps needed so not through the Arduino)
It seems like there are a lot of details missing. Instead of providing them only when asked, please combine everything that you can tell us in one post.
If you don't, it can waste a lot of time. For example, looking at the code won't help if the AT commands don't work.
When the SIM900A is powered on, the Status LED will blink once every second. When the GSM connection has been established the Status LED of the SIM900A will blink every 3 seconds
there is a tutorial here: (not sure what it's worth)
What antenna do you have connected? Have you tried a simple pass through serial sketch (provided in the Arduino example sketches), to verify the serial connection?
what should I do with this one? I am not really sure what's going on. this is my first time using such modules.
/*
SerialPassthrough sketch
Some boards, like the Arduino 101, the MKR1000, Zero, or the Micro, have one
hardware serial port attached to Digital pins 0-1, and a separate USB serial
port attached to the IDE Serial Monitor. This means that the "serial
passthrough" which is possible with the Arduino UNO (commonly used to interact
with devices/shields that require configuration via serial AT commands) will
not work by default.
This sketch allows you to emulate the serial passthrough behaviour. Any text
you type in the IDE Serial monitor will be written out to the serial port on
Digital pins 0 and 1, and vice-versa.
On the 101, MKR1000, Zero, and Micro, "Serial" refers to the USB Serial port
attached to the Serial Monitor, and "Serial1" refers to the hardware serial
port attached to pins 0 and 1. This sketch will emulate Serial passthrough
using those two Serial ports on the boards mentioned above, but you can change
these names to connect any two serial ports on a board that has multiple ports.
created 23 May 2016
by Erik Nyquist
https://www.arduino.cc/en/Tutorial/BuiltInExamples/SerialPassthrough
*/
void setup() {
Serial.begin(9600);
Serial1.begin(9600);
}
void loop() {
if (Serial.available()) { // If anything comes in Serial (USB),
Serial1.write(Serial.read()); // read it and send it out Serial1 (pins 0 & 1)
}
if (Serial1.available()) { // If anything comes in Serial1 (pins 0 & 1)
Serial.write(Serial1.read()); // read it and send it out Serial (USB)
}
}
Substitute the SoftwareSerial port for 'Serial1'. Obviously, you have to include and provision the Software serial library for that. You should know how to do that because your GSM sketch must have it.
