SIM800l at-commands are echoed back.
Posted: Sun Aug 31, 2025 5:46 pm
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
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
---- added ----
The common ground for SIM and ESP cleared the situation. Now is working....
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 806 times
---- added ----
The common ground for SIM and ESP cleared the situation. Now is working....