4-20ma-wifi-bridge

IoT device to provide communication between 4-20mA sensors and cloud services. Powered by an ESP32, it allows a wireless connection via WIFI, the communication with the server is done through the MQTT protocol. The device has a user-friendly web configuration interface, which allows to manage the wifi connection, the connection with the MQTT broker as well as the calibration of the 4-20mA acquisition system.

Features

Hardware

• 5-24v Power supply.
• 1 Input 4-20 mA.
• 2 Relays to control loads up to 1A at 24DVC or 0.5A at 125VAC.
• WIFI 802.11 b/g/n (2.4 GHz), up to 150 Mbps.

Get the source code

Download repository and update submodules:

$ git clone https://github.com/AngelJMC/4-20ma-wifi-bridge.git

Directory Structure

.
├── docs          # Documentation files
├── firmware      # FW source code (Visual Studio Code)
├── hardware      # HW design files (Kicad)

Firmware

If you want to modify the source code or program your devices, it is highly recommended to use Visual Studio Code and the Platformio plugin. Just open the "firmware" directory with Visual Studio Code and the whole project will be ready for use.

Load firmware

1. Build and Upload Filesystem Image.
2. Build and Upload program code.

Configuration Process

1. Build and Upload Filesystem Image to your ESP32
2. Build and Upload program code.
3. Connect mobile or PC with hotspot: Logger_4-20mA_XXXX. Password: Kmf5cyJUWw
4. Go to web browser and hit 192.168.4.1. Use the credential supervisor/fEVcCQxig to enter.
5. Go to Network section and scan for your wifi network, write password and static network configuration if you want, hit apply.
6. Go to Service section give necessary server credential for MQTT and set the pub/sub topic names.
7. Go to Other section if you need calibrate the 4-20mA acquisition electronic.

Configuration Web

Library Used

• ESp32_arduino :- https://github.com/espressif/arduino-esp32
• ESPAsyncWebServer:- https://github.com/me-no-dev/ESPAsyncWebServer
• AsyncTCP:- https://github.com/me-no-dev/AsyncTCP
• esp32 SPIFF File system :- https://github.com/me-no-dev/arduino-esp32fs-plugin

The configuration web page is based on the work of @futechiot https://github.com/futechiot/Configuration-webpage-esp32