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Smart Cities Group Project

Segment Display

The segment display is used to show numerical data such as temperature and humidity readings from the sensors. It is a 8-digit 7-segment display that can display numbers from 00000000 to 99999999. The display is connected to the ESP32 microcontroller via I2C communication protocol. The display is controlled using the LedControl library, which provides functions to initialize the display, set the brightness, and display numbers.

Hardware Connections

  • Power Supply: Connect the VCC pin of the segment display to a 5V power supply.
  • Ground: Connect the GND pin of the segment display to the ground of the ESP32.
  • SPI Data In: Connect the DIN pin of the segment display to GPIO pin 11 on the ESP32.
  • SPI Clock: Connect the CLK pin of the segment display to GPIO pin 12 on the ESP32.
  • SPI Load/Chip Select: Connect the CS pin of the segment display to GPIO pin 10 on the ESP32.

Software Configuration

The project uses the LedControl library to control the segment display. Make sure to include the library in your platformio.ini file:

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lib_deps =
    LedControl

Custom Wrapper Class

A custom wrapper class SegmentDisplay is implemented to manage the segment display operations.

The following functions are available in the SegmentDisplay class:

  • start(): Initializes the segment display.
  • setIntensity(int intensity): Sets the brightness of the display (0-15).
  • clearDisplay(): Clears the entire display.
  • clearLeft(): Clears the left 4 digits of the display.
  • clearRight(): Clears the right 4 digits of the display.
  • setTemp(float temperature): Displays the temperature on the left 4 digits.
  • setHum(float humidity): Displays the humidity on the right 4 digits.