DIY International Space Station Tracker - Code and Circuit

The DIY International Space Station Tracker operates by utilizing an ESP8266-based NodeMCU microcontroller to fetch real-time positional data for the ISS over a Wi-Fi network. Once the NodeMCU processes the incoming orbital coordinates and calculates the relative distance to the observer's location, it drives an array of seven Red LEDs (LED1-LED7) and one Green LED (LED8) to visually represent the proximity and direction of the passing satellite. Each LED is paired with a dedicated 220-ohm current-limiting resistor (R1-R8) to protect the semiconductor junctions from overcurrent by safely dropping the excess voltage supplied by the digital output pins of the board. As the tracking calculations update, the microcontroller sequences the LED array to map out the spatial progression of the tracker. Additionally, a buzzer is integrated into the circuit layout to provide audible alerts, triggering sound cues when specific orbital milestones are reached, such as when the ISS enters a designated geographic radius or an optimal viewing window. Throughout operation, the NodeMCU manages both the network communication stack to pull satellite telemetry and the precise digital I/O switching required to drive the visual and auditory feedback peripherals simultaneously.