ESP32-asyncServer-data

This repository contains an implementation of an asynchronous HTTP webserver for an ESP32 microcontroller. The ESP32, connected to a WiFi network, is used to control a LED as well as read and process the values from a thermistor and a photoresistor.

The communication between the clients and the async webserver is done through websockets. JSON is used as data format and charts.js for data visualization.

Website appearance

Schematic

The following parts have been used in the electronic circuit. Nevertheless, they can be replaced by other similar ones with little change in the code.

• 1x LED.
• 1x MF52D NTC thermistor.
• 1x photoresistor.
• 2x 1 kΩ resistances.
• 1x 10 kΩ resistance.

ESP32 pins in the schematic are referred as 3.3V, GND and D*.

Note: ESP32 ADC2 pins cannot be used when Wi-Fi is used.

Requirements

ESP32 libraries:

• WiFi.h

External libraries:

• ArduinoJson. JSON library for embedded C++.
• AsyncTCP. Async TCP Library for ESP32.
• ESPAsyncWebServer. Async HTTP and WebSocket Server.

Usage

1. Build the circuit as shown in the schematic.
2. Install the standard ESP32 libraries either using the Arduino IDE or directly from Espressif.
3. Install the required external libraries.
4. Download the repository and rename the file constants.h.TEMPLATE to constants.h.
   • Change the SSID and PASSWORD correspoding to the WiFi network.
   • Change the IP address and gateway if necessary in constants.h, index.h and websocketclient.py.
5. Flash the ESP32:
   • For VSCode, modify the arduino.json and c_cpp_properties.json files to add the missing libraries.
   • For the Arduino IDE, change the src folder to match the name of the .ino file.

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change.

License

GPL-3.0