🛠 GPIO en Python : LED et bouton avec gpiozero

Goal

Drive the Zero's 40-pin GPIO from Python: an LED and a button with gpiozero. The Zero's header is electrically identical to the Model A+/B+/2B — 3.3 V logic, Broadcom numbering — but it ships unsoldered, so grab a soldering iron first.

Wiring

• Solder a 40-pin header (or use a pHAT / clamp connector)
• LED + 330 Ohm resistor: physical pin 11 (GPIO17) -> resistor -> LED anode, cathode to GND (e.g. pin 6)
• Push button: physical pin 13 (GPIO27) to GND, using the internal pull-up
• Current budget: 16 mA per pin, 50 mA TOTAL across all pins

Code

#!/usr/bin/env python3
# sudo apt install python3-gpiozero
from gpiozero import LED, Button
import signal

led = LED(17)          # BCM numbering: GPIO17 = physical pin 11
btn = Button(27)       # GPIO27 = physical pin 13, button wired to GND

btn.when_pressed = led.on      # event-driven, no polling loop
btn.when_released = led.off

def bye(s, f):
    led.off
    raise SystemExit

signal.signal(signal.SIGINT, bye)
signal.pause         # block forever; the Zero idles at ~0.1 A while waiting

Run with python3 bouton.py, stop with Ctrl-C.

Check

The LED lights while the button is held and goes off on release; after Ctrl-C the LED is cleanly off.

Pitfalls

• Physical pin 17 is a 3.3 V supply pin, not GPIO17 — BCM numbers are not pin numbers.
• Feeding 5 V sensor outputs into the header: the logic is 3.3 V and NOT 5 V tolerant.
• No ADC/DAC on this board: analog sensors need an external chip (e.g. MCP3008 over SPI).
• Exceeding 16 mA per pin or 50 mA total damages the SoC — drive relays/motors via a transistor.