SIM800l at-commands are echoed back.

[Lartzu]

I hope that some of you can give some advices for me.

The problem is that I'm not get any reasonable replies back to ESP from SIM800L module

Code: Select all

//#define TINY_GSM_MODEM_SIM7080
#define TINY_GSM_MODEM_SIM800


#include <HardwareSerial.h>
#include <TinyGsmClient.h>

#define SerialMon Serial

HardwareSerial gsmSerial(2); 
TinyGsm modem(gsmSerial);
TinyGsmClient client(modem);

void setup() {
  // Set console baud rate
  SerialMon.begin(9600);
  delay(10);

  SerialMon.println("Wait...");
  gsmSerial.begin(9600, SERIAL_8N1, 16, 17); // 

  SerialMon.println("Initializing modem...");
  //modem.restart();
  modem.init();
  delay(2000);

  String modemInfo = modem.getModemInfo();
  SerialMon.print("Modem Info: ");
  SerialMon.println(modemInfo);

}

void loop() {

  SerialMon.println("Sending AT command...");
  
  delay (1000);
  String IMEI = modem.getIMEI();
  Serial.print ("IMEI:");
  Serial.println (IMEI);


}



}

The first line (black) is connected to PIN17 and line 2. is directly connected to RXD in SIM800L module
esp32 17 -> SIM800L RXD
SIM800L TXD-> esp32 16

at-command.png (8.08 KiB) Viewed 802 times

---- added ----

The common ground for SIM and ESP cleared the situation. Now is working....

[ahsrabrifat]

Hello, have you shorted the GND pins? What power supply are you using for the SIM800L module?

[Lartzu]

The common ground for SIM and ESP cleared the situation. Now it is working....

I have an other question related to this.... how to use Data only USB-cable between ESP - WIN (data, and ground connected.)