Building Touchscreen Weather Monitoring System Using Arduino

The Touchscreen Weather Monitoring System operates through the integration of digital sensors, a microcontroller, user interface elements, and electromechanical power control components. At the core of the system is the Arduino Uno, which executes the `weather_light_control.ino` program to coordinate data acquisition, display rendering, and system output. Environmental data is gathered by the DHT22 sensor, a digital relative humidity and temperature sensor that communicates precise atmospheric readings to the Arduino. The Arduino processes these incoming digital signals and updates the TFT Touchscreen Display, providing a graphical user interface where users can view real-time temperature and humidity metrics, as well as interact with touch controls. To bridge the low-voltage control logic of the Arduino with external hardware, a BC548 transistor is configured as an electronic switch. When the Arduino supplies a small base current to the BC548 (regulated by appropriate resistors R1 and R2), it allows a larger current to flow through the coil of the Relay Module. This relay acts as an electrically isolated switch to manage external devices or loads. Additionally, an LED (LED1) serves as a visual indicator for system status. The entire circuit is energized by an external 9V-12V DC Power Supply, which provides the necessary voltage for the Arduino Uno, the relay, and the power-demanding TFT display.