This repository is developed in Kuituhamppu käyttöön -project

https://lapinamk.fi/hanke/kuituhamppu-kayttoon/

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tequ-iot-soil-moisture-esp32

Soil moisture measurement system. Collects data from DFRobot soil moisture sensors. In this project system is used to measure biomass temperature and moisture from three different locations (bottom, middle and top). Biomass is located in compost unit.

System can send data using BLE or Wi-Fi connection.

Javascript module to receive and forward BLE advertisement data is programmed for Shelly devices. Data is forwarded to local MQTT broker. Javascript module is ble-soilmoisture.js in repository files.

System is designed to 6-12 months without need to change batteries.

System can be expanded to collect data from Ruuvitags and use LoRaWAN to send data. This functionality is programmed, but not fully tested and connections for LoRaWAN is not directly available on current PCB.

Hardware

Hardware components are built on PCB designed for the project and PCB is placed in industrial IP68 rated enclosure. PCB is developed using LibrePCB.

Enclosure model is Hammond 1555EF17GY.

https://www.mouser.fi/datasheet/2/177/1555f-1389823.pdf

Hardware	Model	Placement	Link
Main board	Seeed XIAO ESP32S3	Enclosure	Link
RS485 Module	Grove - RS485	Enclosure	Link
DC/DC module	Adafruit 4654	Enclosure	Link
Battery pack	3.7 LiPo 2000 mAh	Enclosure	Link
Soil moisture sensor	DFRobot	Composter	Link

Schematics

Wiring and connections.

Development

1. Install Thonny (https://thonny.org/)

2. Connect and verify ESP32

3. Build connections between devices and configure soil moisture sensors (Modbus addresses 11,12,13)

4. Update ESP32 Micropython using Thonny

5. Clone this repository

git clone https://github.com/Lapland-UAS-Tequ/tequ-iot-soil-moisture-esp32

7. Create settings.json

In the repository you'll find template files.

8. Open folder in Thonny and upload files into device

9. Run project and verify operation