sim800l gprs + mqtt

[Nicolaf899]

Is there an example to use the m5stack with the sim800l module and to use the mqtt protocol?

[crami25]

@Nicolaf899

I'm also planning to try it. I will follow the step by step tutorial from Random Nerd Tutorials (Rui and Sara Santos).
Here is the link to their tutorial sending data collected from a BME 280 (M5Stack ENV unit) using an ESP32 to a MTTQ cloud:

https://randomnerdtutorials.com/esp32-sim800l-publish-data-to-cloud/

I'm planning using M5stacks monitoring beehives and sending data (environement, weight, sound recording, beecount) to an MTTQ Sever either by WiFi, gprs or LoRa.

good luck crami25

[lukasmaximus]

I was unable to get sim800l working when I tried, but then I think thats due to me not knowing how to debug it. There are quite a few resources around the forum and elsewhere if you search

http://forum.m5stack.com/topic/539/lesson-22-modules-sim800l
http://forum.m5stack.com/topic/164/sim800l/3
https://www.hackster.io/merryq/automation-with-sim800l-esp32-m5stack-170a82
http://forum.m5stack.com/post/7490
http://forum.m5stack.com/post/2688
http://forum.m5stack.com/topic/595/how-to-use-gps-module-with-sim800l-module/9

[Nicolaf899]

To start understanding the functioning of the sim800l module I used the following example:

//Reset resistance is not soldered. If necessary, weld it yourself.

#include <M5Stack.h>
#define RX_PIN 16
#define TX_PIN 17
#define RESET_PIN 5

void header(const char *string, uint16_t color){
M5.Lcd.fillScreen(color);
M5.Lcd.setTextSize(1);
M5.Lcd.setTextColor(TFT_MAGENTA, TFT_BLUE);
M5.Lcd.fillRect(0, 0, 320, 30, TFT_BLUE);
M5.Lcd.setTextDatum(TC_DATUM);
M5.Lcd.drawString(string, 160, 3, 4);
}

void setup() {
M5.begin();

header("SIM800L AT command", TFT_BLACK);
M5.Lcd.setTextFont(2);
M5.Lcd.setTextColor(TFT_WHITE, TFT_BLACK);
M5.Lcd.drawString("Please use serial port to Test AT command.",0, 35, 2);
// Host serial communication
Serial.begin(115200);

// SIM800L serial communication
Serial2.begin(115200, SERIAL_8N1, RX_PIN, TX_PIN);
pinMode(RESET_PIN, OUTPUT);
}

void loop() {

//AT instruction write
if(Serial.available()){
Serial2.write(Serial.read());
}

//AT instruction result
if(Serial2.available()){
Serial.write(Serial2.read());
}

delay(10);

}

I sent some at command to understand if the module worked but apparently it doesn't work. Any suggestions?