RDY +CFUN: 1 +CPIN: READY Call Ready SMS Ready RDY +CFUN: 1 +CPIN: READY Call Ready SMS Ready serial communications with the SIM800L 44module. The communications interface to the SIM800L is an RS-232 style serial port, with just two pins with signal levels under 5 Volts, but it seems to be compatible with 5V GPIO pins on the Raspberry Pi. I think the SMS limit is based on the SMS storage capacity of the SIM800 module. You need to check the datasheet to exactly know the capacity. If you check the GSMSIM library (GSMSim.cpp) there are three functions to delete SMS (I didn't check them actually). You can use them.
Introduction to SIM800L
- To send an SMS with the T-Call ESP32 SIM800L module, you just need to use modem.sendSMS(SMSTARGET, smsMessage) after initializing a modem object for the SIM800L module (using the TinyGSM library). Important: the SIM800L works on 2G networks, so it will only work in your country, if 2G networks are available.
- Stm32 read sms and post to web server from sim800l - main.c.
There are so many GSM modules that came to market right now. And SIM800L almost the cheapest. It cost under 10$ and has the same feature as other. So, this module is a great one.
This module works just like another module, it uses AT Command to communicate with arduino and has the same command. You can download the AT command list it uses here.
Just like another GSM module like SIM900A that we’ve wrote the tutorial here. This is of course use serial communication to communicate with arduino. So we need Tx and Rx here.
Arduino and SIM800L Wiring Diagram
arduino and SIM800L wiring diagramConnect your arduino and SIM800L like above. But this seems like to be wrong. Because in the datasheet it says that VCC must be at 4.4V maximum. But in last version of this module, it works given 5V for it’s VCC.
if it is doesn’t work for you can try to drop the VCC to not more than 4.4V. You can use buck converter, or the simplest way just use a diode. I will prefer use only a diode because it simplicity. So, wiring diagram become like below :
The Code
Sending a message:
In this example, we made two function that is SendMessage() and _readSerial(). SendMessage() to send message and _readSerial() to read the answer from SIM800L.
To make a call you can create another function and call that function from your loop. And this is the function :
I mixed up the code to send and receive sms and make a call. Every task in a function. So it has three function, SendMessage(), ReceiveMessage() and Call(). In this code you just type in serial monitor “s” to send, “r” to receive SMS, and “c” to make a call.
And that’s all the code. That is easty Isn’t it? And if you need a tutorial on how to send data over GPRS with this module, wait our next tutorial.
Watch also complete video tutorial below :
AT
AT+CMGF=1
AT+CPMS='SM'
AT+CMGL = 'ALL'
63
AT
OK
AT+CMGF=1
OK
AT+CPMS='SM'
+CPMS: 2,25,2,25,2,2
The sim has two SMSes that can be viewed when you run the commands via USD
The code is
byte gsmDriverPin[3] ={3,4,5};
int numdata;
boolean started=false;
char smsbuffer[160];
char n[20];
String inData;
void setup() {
//pinMode(13, OUTPUT); digitalWrite(5,HIGH);//Output GSM Timing
delay(1500);
digitalWrite(5,LOW); digitalWrite(3,LOW);//Enable the GSM mode
digitalWrite(4,HIGH);//Disable the GPS mode
delay(2000);
mySerial.begin(9600); // the GPRS baud rate
mySerial.print('r');
delay(1000);
Serial.begin(9600); //set the baud rate
delay(5000);//call ready
delay(5000);
delay(5000);
Sim800l Delete All Sms App
//Init the driver pins for GSM function
for(int i = 0 ; i < 3; i++)
{
pinMode(gsmDriverPin[i],OUTPUT);
}
}
void loop()
{
Serial.println('AT'); //AT is sent to the GSM / GPRS modem to test the connection
delay(2000);
//Serial.println('AT');
// p_char=Serial.read();
//Serial.write(p_char);
// delay(2000);
Serial.println('AT+CMGF=1'); //instruct the GSM/GPRS modem or mobile phone to operate in SMS text mode.
Sim800l Delete All Sms Contacts
delay(2000);
// p_char=Serial.read();
//Serial.write(p_char);
delay(2000); Serial.println('AT+CPMS='SM'); // instruct the GSM/GPRS modem or mobile phone to use the message storage area in the SIM card
delay(2000);
//Serial.write(Serial.read());
//delay(2000);
Serial.println('AT+CMGL = 'ALL'); //retrieve all SMS messages received
delay(2000);
if (Serial.available() )
{
Sim800l Delete All Sms Card
int h=Serial.available();
Serial.println(h);
for (int i=0;i<h;i++)
{
inData += (char)Serial.read();
}
// if you are getting escape -characters try Serial.read(); here
//print it out
Serial.println(inData);
}
else
{
Serial.println('Not Available');
}
while (1);