This project is part of the 5ISS program at INSA Toulouse. We developed a nanoparticle-based gas sensor at AIME, the INSA Toulouse laboratory. Then, we designed a PCB and developed ESP32 code to exploit the sensor and display its data on a web interface.
- Introduction
- LoRa and LoRaWAN
- The Things Network (TTN)
- LTspice
- KiCad
- Node-RED
- AppInventor
- Datasheet
- Possible Improvements
- Contacts
This project allowed us to develop a complete system for exploiting a gas sensor, including:
- Designing a shield PCB for the ESP32.
- Connecting to the LoRaWAN network via The Things Network (TTN).
- Visualizing data through an interactive dashboard on Node-RED.
The main microcontroller used is an ESP32 with an integrated LoRa module. To simulate the gas sensor developed at AIME, we also used an industrial Grove MQ-3B sensor.
This repository contains:
- Arduino source code to collect data, display it locally, and send it to TTN.
- The KiCad files for the shield PCB, including the schematic and the final assembled model.
- The Node-RED flow and its associated web dashboard.
- The complete datasheet of the sensor.
Here are some images of the final product:
LoRa (Long Range) is a wireless communication technology designed to transmit data over long distances with low energy consumption.
In this project, we started by establishing point-to-point communication between two modules.
Later, we registered the module on INSA's LoRaWAN network to securely send our sensor data and retrieve it via ChirpStack.
Due to issues with INSA's gateway, we decided to deploy our own LoRa gateway on The Things Network (TTN).
TTN is a platform that enables the connection and management of LoRaWAN devices. The main steps in integrating with TTN were:
- Registering our ESP32 sensor on TTN.
- Visualizing the frames sent by the sensor.
- Retrieving the data on Node-RED via the MQTT protocol.
We used LTspice to simulate and size the components of the sensor's signal adaptation stage. This ensured reliable and accurate data acquisition before processing it with the microcontroller.
You can learn more by reading the dedicated README in the simulation section.
We designed the shield PCB for the ESP32 on KiCad, integrating:
- Signal adaptation for the gas sensor.
- Connectors for simplified integration.
Here is a view of the assembled shield:
For more details, check the dedicated README on routing.
Node-RED is a block-based programming platform used to create web interfaces. We developed a dashboard to display real-time sensor data.
Here is our dashboard:
The datasheet of the gas sensor developed at AIME details its technical characteristics, manufacturing process, and usage specifications. It is available in the /datasheet directory.
Using AppInventor, we designed a mobile application capable of directly communicating with a Bluetooth receiver to turn an LED on or off. You can view the application and its source files in the /appinventor directory.
- Integrate more sensors to expand measurement capabilities.
- Optimize the power management of the microcontroller for better autonomy.
- Develop a mobile application to control and visualize the sensor's data.
For any questions or suggestions regarding this project, feel free to contact us:
- Name: Clément Gauché & Noël Jumin
- Email: clement.gauche@insa-toulouse.fr & noel.jumin@insa-toulouse.fr
- GitHub: @Raspeur & @NoNo47400