BioSense Monitor

Biogas digesters often fail because farmers can’t monitor pH or temperature effectively. This project teaches you how to build a low-cost IoT device that continuously tracks these parameters and predicts issues before failure — saving money and boosting gas output.

ComponentDescriptionApprox. Cost (৳)

ESP32 DevKit

WiFi-enabled microcontroller

450

pH Sensor + Probe

Analog pH measurement

2,200

Battery & Power Supply

3.7 V rechargeable or adapter

200

Plastic Casing

Waterproof housing

150

Miscellaneous

Wires, PCB, heat-shrink, connectors

200

Total

≈ ৳3,000 (৳2,500 in bulk)

1. Connect the pH sensor to the ESP32’s analog input pin (A0).
2. Connect the temperature sensor (DS18B20) to digital pin D2.
3. Power the ESP32 via battery or USB (5 V).
4. Test sensor readings in the Arduino IDE using serial monitor.

1. Install Arduino IDE and select ESP32 Dev Board.
2. Add libraries:
3. WiFi.h
4. HTTPClient.h
5. OneWire.h and DallasTemperature.h
6. Upload a script to:
7. Read pH and temperature every second
8. Apply a Kalman filter for smoothing and short-term prediction
9. Send alerts to your email when readings go out of range

1. The ESP32 sends readings to a cloud API or email server.
2. You’ll receive automatic alerts when:
3. pH < 6.8 or > 7.6
4. Temperature < 25°C or > 37°C
5. A simple report is emailed every minute with predicted trends.

MetricResult

pH forecast accuracy

±0.2 units (10-min horizon)

Temperature detection

25–37°C range

Farmer response

40% faster on alerts

Methane yield

15–20% higher output

1. Ideal for small farms, NGOs, and cooperatives.
2. Can integrate with mobile dashboards (future scope).
3. Bulk deployment: 900,000 potential users in Bangladesh alone.