GSMToolsTestModem

Read the IMEI of your modem and print it in the Serial Monitor.

GSM Test Modem

This sketch tests the modem on the GSM shield to see if it is working correctly. You do not need a SIM card for this example.

Hardware Required

Circuit

image of the Arduino GSM Shield on top of an Arduino board
image of the Arduino GSM Shield on top of an Arduino board

Code

First, import the GSM library

#include <GSM.h>

Create an instance of the GSMModem class:

GSMModem modem;

Create a variable to hold the IMEI number of the modem

1String IMEI = "";

In

setup
, open a serial connection to the computer. After opening the connection, send a message indicating the sketch has started.

1void setup(){
2
3 Serial.begin(9600);
4
5 Serial.print("Starting modem test...");

Call

modem.begin()
to start the modem. Send a status message depending on the outcome, and end
setup()
.

1if(modem.begin())
2
3 Serial.println("modem.begin() succeeded");
4
5 else
6
7 Serial.println("ERROR, no modem answer.");
8}

Inside

loop
, use
modem.getIMEI()
to return the IMEI number of the modem. This number is unique to your GSM shield.

1void loop()
2{
3
4 // get modem IMEI
5
6 Serial.print("Checking IMEI...");
7
8 IMEI = modem.getIMEI();

If there is a valid response from

getIMEI()
, print it to the serial monitor and reset the modem with
modem.begin()
.

1if(IMEI != NULL)
2
3 {
4
5 // show IMEI in serial monitor
6
7 Serial.println("Modem's IMEI: " + IMEI);
8
9 // reset modem to check booting:
10
11 Serial.print("Resetting modem...");
12
13 modem.begin();

Once reset, check the IMEI again. If it is a valid return again, the modem is functioning as expected.

1if(modem.getIMEI() != NULL)
2
3 {
4
5 Serial.println("Modem is functioning properly");
6
7 }

If, after resetting the modem, there is not a valid return from

getIMEI()
, report an error

1else
2
3 {
4
5 Serial.println("Error: getIMEI() failed after modem.begin()");
6
7 }

If you never received an IMEI after starting the sketch, report it, and end the program.

1}
2
3 else
4
5 {
6
7 Serial.println("Error: Could not get IMEI");
8
9 }
10
11 // do nothing:
12
13 while(true);
14}

Once your code is uploaded, open the serial monitor. You should see the HTML of http://arduino.cc print out on screen when it is received.

Complete Sketch

The complete sketch is below.

1/*
2
3 This example tests to see if the modem of the
4
5 GSM shield is working correctly. You do not need
6
7 a SIM card for this example.
8
9 Circuit:
10
11 * GSM shield attached
12
13 Created 12 Jun 2012
14
15 by David del Peral
16
17 modified 21 Nov 2012
18
19 by Tom Igoe
20
21 http://www.arduino.cc/en/Tutorial/GSMToolsTestModem
22
23 This sample code is part of the public domain
24
25 */
26
27// libraries
28#include <GSM.h>
29
30// modem verification object
31
32GSMModem modem;
33
34// IMEI variable
35
36String IMEI = "";
37
38void setup() {
39
40 // initialize serial communications and wait for port to open:
41
42 Serial.begin(9600);
43
44 while (!Serial) {
45
46 ; // wait for serial port to connect. Needed for Leonardo only
47
48 }
49
50 // start modem test (reset and check response)
51
52 Serial.print("Starting modem test...");
53
54 if (modem.begin()) {
55
56 Serial.println("modem.begin() succeeded");
57
58 } else {
59
60 Serial.println("ERROR, no modem answer.");
61
62 }
63}
64
65void loop() {
66
67 // get modem IMEI
68
69 Serial.print("Checking IMEI...");
70
71 IMEI = modem.getIMEI();
72
73 // check IMEI response
74
75 if (IMEI != NULL) {
76
77 // show IMEI in serial monitor
78
79 Serial.println("Modem's IMEI: " + IMEI);
80
81 // reset modem to check booting:
82
83 Serial.print("Resetting modem...");
84
85 modem.begin();
86
87 // get and check IMEI one more time
88
89 if (modem.getIMEI() != NULL) {
90
91 Serial.println("Modem is functioning properly");
92
93 } else {
94
95 Serial.println("Error: getIMEI() failed after modem.begin()");
96
97 }
98
99 } else {
100
101 Serial.println("Error: Could not get IMEI");
102
103 }
104
105 // do nothing:
106
107 while (true);
108}

Last revision 2018/08/23 by SM

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