🛠 Premier démarrage headless de la Zero W (Wi-Fi + SSH)

Objectives

Flash Raspberry Pi OS, preconfigure Wi-Fi and SSH with Raspberry Pi Imager, then boot without a screen or keyboard (headless).

Hardware

• 1 Raspberry Pi Zero W (BCM2835 1 GHz, 512 MB)
• 1 microSD card 8 GB min. + reader
• 1 power supply 5 V / 1.2 A (official recommendation) + micro-USB cable

Steps

1. In Raspberry Pi Imager, choose Raspberry Pi OS Lite (32-bit): the Zero W's ARMv6 core only runs in 32-bit (armhf).
2. Custom settings: hostname zerow, SSH enabled, credentials, Wi-Fi and WLAN country — the regulatory domain determines channels and power.
3. Write the card. Plan B: an empty ssh file at the root of the boot partition also reactivates SSH.
4. Power via the PWR port (the other port is the OTG data port). The ACT LED (GPIO47, active-low) blinks during boot then settles once Wi-Fi is connected.
5. From the PC: ssh pi@zerow.local, then nmcli -t -f IP4.ADDRESS dev show wlan0 (DHCP lease).

Verification

uname -m returns armv6l; vcgencmd measure_temp stays well below the throttling threshold (80–85 °C).

Common Errors

• Plugging the power supply into the OTG data port: nothing boots.
• Forgetting the WLAN country: forbidden 2.4 GHz channels or reduced power.
• No under-voltage detection on the Zero range: a weak power supply corrupts the SD card without kernel warning.