NBIOT/LTE-M Air Monitor - A solar-powered ESP32-S3 multi-sensor board with SIM7080G NB-IoT & LTE-M modem

The NBIOT/LTE-M Air Monitor is a solar-powered device that utilizes a combination of ESP32-S3 and SIM7080G modules for remote environmental monitoring. It monitors and transmits environmental parameters such as temperature, humidity, CO2, TVOC, and light intensity using low-power wide-area network (LPWAN) technology ensuring efficient power consumption, durability, and reliable data transmission.

Previously we have written about similar environment monitor devices like the Airlytix ES1, Sonoff SC WiFi, V-Air Monitro, and devices like Arduino MKR IoT Carrier Rev2, Radair mini gateway, and Nicla Sense ME designed for environment monitoring applications. Feel free to check those out if you are interested in this type of product.

NBIOT/LTE-M Air Monitor specification

Wireless Module – ESP32-S3-WROOM-1-N16R8
- Espressif Systems ESP32-S3R8 – Dual-core Tensilica LX7 @ up to 240 MHz with vector instructions for AI acceleration, 512KB RAM, 8MB PSRAM
- Storage – 16 MB flash
- Wireless – 2.4 GHz WiFi 4 and Bluetooth
- PCB antenna
Cellular connectivity
- Module – SIMCom SIM7080G LTE Cat M1/NB-IoT module with GNSS
- Bands
  - Cat-M – B1/B2/B3/B4/B5/B8/B12/B13/B14/B18/B19/B20/B25/B26 /B27/B28/B66/B85
  - NB-IoT – B1/B2/B3/B4/B5/B8/B12/B13/B18/B19/B20/B25/B26/B28 /B66/B71/B85
- Data rate
  - LTE Cat-M1 – Uplink: 589Kbps, downlink: 1119Kbps
  - LTE Cat-NB2 – Uplink: 136Kbps, downlink: 150Kbps
- GNSS Positioning – GPS, GLONASS, BeiDou, and Galileo
- SIM card socket
Antennas
- PCB antenna on ESP32-S3 module for Wi-Fi and Bluetooth
- External NBIOT/LTE-M antenna
- External LTE antenna connector
- External GPS antenna connector
Environmental Monitoring Sensors
- ASAIR ATH10 Temperature and humidity sensor
  - Humidity Measurement Range: 0 – 100% RH
  - Humidity Measurement Accuracy: +/- 2% RH
  - Temperature Measurement Range: -40°C – 85°C
  - Temperature Measurement Accuracy: +/- 0.3°C
- SENSIRION SGP30 TVOC and CO2eq Measurements Sensor
  - CO2eq signal Range: 400~60000ppm
  - CO2eq signal Accuracy: 10% of meas. value
  - TVOC signal Range: 0 to 60000 ppb
  - TVOC signal Accuracy: 15% of meas. value
- ROHM BH1750 Ambient Light Sensor
  - Light intensity Range: 1 – 65535 lx
  - Light intensity Accuracy: 0.96 to 1.44 S/A times
Misc
- On/off switch
- Flash, WiFi, RST, PWK, and Boot buttons
Power Management
- Input Voltage – 4.5 to 28V for solar panel input
- Internal 18650 LiPo battery socket
- BMS – DW06 one-cell battery protection IC
  - Protection of charger reverse connection
  - Protection of battery cell reverse connection
  - Over temperature protection
  - Overcharge current protection
  - Over-discharge protection
- MPPT – CN3791 for solar maximum power tracking charging management
Temperature Range – -40°C to +85°C

As I noticed, there is only a programming pin available. To program, plug the USB2UART CH340K module into the “P1” header (‘The “P1” connector is a 6-pin programmable header for the ESP32, including pins for RST, BOOT, TXD, RXD, GND, and VOUT.). This module provides USB to serial conversion and includes the necessary circuits for ESP8266/ESP32 programming.

Makerfabs highlights Arduino support with the ESP32-S3 wireless module and also explains how to send an email from the air monitor and integrate it with ThingSpeak IoT cloud. You will find more information about hardware, programming, drivers, and firmware on the wiki and GitHub pages.

Sensor data charts with Thingspeak integration — Example charts in Thingspeak with data from the NBIOT/LTE-M Air Monitor

The NBIOT/LTE-M Air Monitor is available on its official Makerfabs store for $68.80 plus shipping. The additional ESP32 Programmer board (USB2UART CH340K) is also available in the same store at $3.90.

Sayantan Nandy

Sayantan Nandy, an electronics engineer with over four years of hands-on experience in PCB design, circuit development and power electronics, is proficient in EAGLE CAD, Ki-Cad, and Altium. He has a proven track record of delivering efficient and effective systems. His expertise extends from R&D, and prototyping to production support, making him a valuable asset to any engineering team.