ESP32 with DS18B20 Multiple Temperature Sensors Web Server

Uses multiple DS18B20 digital temperature sensors on a single wire (one-wire protocol) with ESP32. Each DS18B20 has a unique 64-bit serial number so you can identify them individually. Up to 127 sensors on a single GPIO pin. The web server displays all sensor readings with their addresses and lets you assign friendly names (stored in SPIFFS). All sensors read simultaneously. Use case: multi-zone HVAC monitoring, freezer/fridge temperature logging, outdoor/indoor temperature comparison. Circuit: all DS18B20 DATA pins to GPIO4, single 4.7k Ohm pull-up to 3.3V. Resolution: 9-bit (0.5C, 94ms) to 12-bit (0.0625C, 750ms) configurable. Libraries: OneWire, DallasTemperature, WiFi, ESPAsyncWebServer, SPIFFS, ArduinoJson.

Detailed Project Description

ESP32 with DS18B20 Multiple Temperature Sensors Web Server connects an embedded device to the network so its data can be viewed and its outputs controlled from a browser, app or cloud service.

How It Works
1. The device joins the network and registers with the server/cloud (or hosts its own web page).
2. Sensor values are published and outputs are controlled through HTTP, MQTT, BLE or a cloud SDK.
3. A web/app front-end shows live values in gauges and charts and offers control buttons.
4. Data is stored for history and the firmware can be updated over the air where supported.

Key Components and Their Role
- ESP32: dual-core Wi-Fi + Bluetooth microcontroller that runs the firmware, reads the sensors and hosts the network connection.
- DS18B20: 1-Wire digital temperature probe (waterproof versions available).

Implementation Steps
1. Collect the components and study each module's datasheet (pin-out, voltage, interface).
2. Wire the circuit on a breadboard following the pin mapping; power sensors from the correct rail (3.3 V / 5 V).
3. Install Arduino IDE, OneWire Library, DallasTemperature Library and the required libraries; flash a minimal test sketch for each module separately.
4. Write the main firmware: read sensors → process → drive outputs / send data.
5. Configure network or cloud credentials and test communication end-to-end.
6. Calibrate thresholds, add error handling (reconnect, sensor time-out) and run a long-duration test.
7. Finalise on a PCB / enclosure and document wiring, code and results.

Key Features
- Live data in the browser/app
- Remote control
- History storage
- Secure access

Expected Output
On completion the student will have a responsive web/app dashboard reflecting the device state in real time.

Deliverables
- Complete source code with comments
- Circuit diagram and pin mapping
- Project report with screenshots and results
- Demonstration-ready build