Buttons, Buzzers and Events

10 Lektionen in dieser Stufe

1. Reading a Push Button with Pull-Up and Pull-Down Resistors
   Explain a floating input and fix it with internal or external pulls. · Lab: Wire a button to GPIO and ground, read it with Button and observe what happens with pull_up=None and no resistor.
2. Polling Versus Events: when_pressed Callbacks
   Replace a busy loop with callbacks that run when something happens. · Lab: Write the same button-toggles-LED program as a polling loop and as callbacks, and compare CPU use.
3. Taming Switch Bounce
   Recognise contact bounce and remove it with bounce_time. · Lab: Count presses with and without debouncing and record how many false counts you get.
4. Long Presses, Double Presses and Hold Timers
   Give one button several functions using hold_time and timing logic. · Lab: Make a short press toggle an LED and a two-second hold switch everything off.
5. Making Sound with Active and Passive Buzzers
   Drive both buzzer types and play notes with TonalBuzzer. · Lab: Beep an active buzzer, then play a short scale on a passive one.
6. Detecting Movement with a PIR Sensor
   Wire a PIR module and tune its sensitivity and hold time. · Lab: Light an LED on motion using MotionSensor and adjust both trimmers until it behaves.
7. Door and Window Sensing with a Reed Switch
   Use a magnetic contact as a normally-closed alarm input. · Lab: Log open and close events of a box lid with timestamps.
8. Connecting Devices in Code with source and values
   Link inputs to outputs declaratively using gpiozero's source chain. · Lab: Make an LED follow a button, then invert and combine two inputs with source tools.
9. Keeping Scripts Alive and Exiting Cleanly
   Use pause, handle Ctrl+C and release pins on exit. · Lab: Add a clean shutdown path to an earlier script so no LED is left on.
10. Building a Reaction-Time Game
    Combine random delays, timing and input events into a complete program. · Lab: Build a two-player game that lights an LED after a random wait and names the faster player.

Abschlussprojekt

A desk alarm that is armed and disarmed with a long button press, watches a PIR sensor and a door contact, and sounds a buzzer with a status LED.

Teile für diese Stufe

• 1 × Raspberry Pi 5 or Pi 4 set from Level 1
• 1 × Breadboard and jumper wire set from Level 6
• 4 × Tactile push button 12 mm
• 1 × Active buzzer module 3.3 V
• 1 × Passive piezo buzzer
• 1 × PIR motion sensor module
• 1 × Magnetic reed switch with magnet
• 1 × LED and resistor assortment from Level 6

In jeder Lektion legst du die passenden Teile direkt in den Warenkorb. Raspberry Pi →