LilyGO T-SIM7080G S3

SensMonitor integration

LilyGO T-SIM7080G-S3

Connect an ESP32-S3, SIM7080G Cat-M/NB-IoT modem and BME280 sensor to the SensMonitor platform using the open-source smonitor-iot firmware.

Start installation Device registration
  • ESP32-S3Wi-Fi, Bluetooth LE, 16 MB flash
  • SIM7080GNB-IoT, LTE-M and GNSS
  • BME280Temperature, humidity and pressure
LilyGO T-SIM7080G-S3 development board
Photo: LILYGO T-SIM7080G S3

01 / Overview

A modern NB-IoT / LTE-M monitoring node

The LilyGO T-SIM7080G-S3 combines an ESP32-S3 microcontroller with a SIM7080G cellular modem. It is a strong candidate for remote monitoring stations where Wi-Fi is not available and low-power cellular connectivity is preferred.

01

Controller

ESP32-S3-WROOM-1 based board with Wi-Fi, Bluetooth LE, flash and PSRAM.

02

Cellular network

SIM7080G supports LTE-M and NB-IoT depending on operator coverage and SIM plan.

03

GNSS location

The SensMonitor profile can read GNSS location before starting the cellular data session.

04

Sensor telemetry

The initial profile uses a BME280 sensor connected over an external I2C bus.

What does the firmware do? On startup, it derives a unique serial number from the ESP32-S3 eFuse MAC address, initializes board power, starts the modem, reads GNSS location when available, establishes PPP data connectivity, synchronizes time, downloads device configuration and sends measurements to SensMonitor.

02 / Preparation

What you need

✓

LilyGO T-SIM7080G-S3 board

✓

Nano SIM card with active LTE-M or NB-IoT data plan

✓

LTE antenna connected before powering the modem

✓

GNSS antenna if location is required

✓

BME280 I2C module and four wires

✓

USB-C data cable connected to ESP-USB

✓

Linux, macOS or Windows computer with Git

✓

ESP-IDF 5.x development environment

Before powering the board Insert the SIM card while the board is powered off, connect the LTE antenna, verify APN settings and confirm LTE-M or NB-IoT availability with your mobile operator.

03 / Hardware

Connect the BME280

The default SensMonitor profile for this board uses GPIO 13 for SDA, GPIO 21 for SCL and I2C address 0x76. If your module uses 0x77, change the address later in configuration.

BME280LilyGOFunction
VIN / VCC3.3VPower
GNDGNDGround
SDAGPIO 13I2C data
SCLGPIO 21I2C clock
LilyGO T-SIM7080G-S3 board
The board photo is provided for reference. Use the wiring table and your board revision markings when connecting sensors.
Modem and board pins used by the firmware
TX GPIO 5RX GPIO 4PWRKEY GPIO 41DTR GPIO 42RI GPIO 3PMU SDA GPIO 15PMU SCL GPIO 7

These connections are routed on the board and do not need to be wired manually. The PMU bus is used internally for AXP2101 power initialization.

04 / Firmware

Install and configure smonitor-iot

The project targets ESP-IDF 5.x. Internet access is required during the first build so ESP-IDF Component Manager can download SensMonitor components.

  1. 1

    Install ESP-IDF 5.x

    Follow the official Espressif instructions, then open a terminal with the ESP-IDF environment activated.

    ESP-IDF installation guide ↗

  2. 2

    Download the firmware

    git clone https://github.com/sensmonitor/smonitor-iot.git
cd smonitor-iot
idf.py set-target esp32s3
  3. 3

    Configure the board profile

    cp examples/lilygo_sim7080_s3/sdkconfig.defaults sdkconfig.defaults.local
idf.py menuconfig

    Open the SensMonitor IoT menu and configure APN, PPP authentication, preferred network mode and optional LTE/NB-IoT band settings.

  4. 4

    Check the sensor configuration

    In SensMonitor IoT → I2C sensor, keep BME280, SDA 13, SCL 21 and address 0x76 unless your wiring is different.

  5. 5

    Build and flash

    idf.py build
idf.py -p /dev/ttyACM0 flash monitor

    Replace /dev/ttyACM0 with your board serial port, such as /dev/ttyUSB0 on Linux or COM5 on Windows.

05 / SensMonitor

Register the device

The firmware automatically derives a serial number from the factory ESP32-S3 MAC address. The serial number identifies the device and is not a secret.

smonitor_iot: Device serial:
SM-ESP32-A1B2C3D4E5F6

DEVICE_NOT_REGISTERED:
Register SM-ESP32-A1B2C3D4E5F6
in the SensMonitor application.
  1. 1

    Sign in at app.sensmonitor.com.

  2. 2

    Open the Devices section and add a new device.

  3. 3

    Select LilyGO T-SIM7080G-S3 as the device type.

  4. 4

    Enter the serial number exactly as shown in the monitor.

  5. 5

    Create a station, assign the device and configure BME280 sensors.

  6. 6

    Restart the board so the firmware can request configuration again.

06 / Verification

What a successful connection looks like

AXP2101 modem power enabled
BME280 initialized successfully
GPS location: latitude=...
Modem connected to PPP server
WebSocket connected
Received device-sample-ack

Ready to measure?

Monitor field data in real time.

Open SensMonitor Firmware on GitHub

Technical sources: SensMonitor firmware, LILYGO product page and LilyGo Modem Series.

Photos belong to their original owner and should be served from the official LILYGO CDN or your uploaded media copy.

LilyGO T-SIM7080G S3