2.2 Push Button LED Controller

This tutorial demonstrates how to control LED illumination using a tactile switch input.

Required Components

  • Raspberry Pi Pico W x1

  • MicroUSB cable x1

  • 830 Tie-Points Breadboard x1

  • LED x1

  • 6*6 Button x1

  • Resistor 220Ω x1

  • Resistor 10kΩ x1

  • Jumper Wire Several

Circuit Connections

../_images/ButtonLED_Wiring.png

  • Connect one button terminal to 3.3V power supply, while linking the opposite terminal to GP14, ensuring GP14 receives high voltage when the switch is activated.

  • Without button activation, GP14 remains in an undefined floating state, potentially reading either high or low. To ensure reliable low-level detection during button release, connect GP14 to ground through a 10kΩ pull-down resistor.

Programming Implementation

Note

  • Follow the visual programming guide below using drag-and-drop methodology.

  • Load 2.2_Button_Control_LED.png from the directory Ultimate-Starter-Kit-for-Pico-W\Piper_Make. For complete instructions, reference Loading Existing Projects.

../_images/ButtonLED_Code.png

Upon Pico W connection, press the Start button to initiate code execution. LED activation occurs when the button is pressed, while LED deactivation happens upon button release.

Functional Analysis

Button activation drives pin14 to high state. The program logic reads pin14 status: if high, pin15 activates (LED illuminates); otherwise, pin15 deactivates (LED extinguishes).

  • [if () do () else ()]: Conditional logic block that evaluates the [if] condition to determine execution path - either [do] block contents or [else] block contents.

  • [is pin () HIGH]: Pin state detection function that compares actual pin voltage level against specified HIGH/LOW threshold, executing [do] block for matches or [else] block for mismatches.