I bought the following Sim800L GSM module. The module is calling and sending messages, but I can not control arduino by sending messages. In addition, the module does not respond to AT commands. Can anyone with experience in this matter help me?
#include <SoftwareSerial.h>
SoftwareSerial GPRS(7, 8); // RX, TX
void setup()
{
GPRS.begin(9600);
Serial.begin(9600);
}
void loop()
{
while(GPRS.available())
Serial.write(GPRS.read());
while (Serial.available())
GPRS.write(Serial.read());
}
I use this code. I am using a 2A 15V power supply and LM2596 DC-DC.
The circuit diagram is as follows.