🛠 Wi-Fi 6 et Bluetooth 5.4 : se connecter, choisir l'antenne, connaître sa révision

Objectives

Leverage the ZERO 3W's key strength: a Wi-Fi 6 (802.11 ax, 2.4 + 5 GHz) and Bluetooth 5.4 module in a Pi Zero form factor — rare at this price point. However, the source datasheet is clear: early boards shipped with an AP6212 (2.4 GHz only, BT 4.0), while the current revision V1.12I features a dual-band module (BL-M8800DS2 / FCS960KAAMD). The first step is to identify what you have, then connect via CLI, and understand the dual antenna path (onboard + u.FL, software-switched).

Hardware

• 1 booting Radxa ZERO 3W (see the flashing tutorial)
• A 2.4 GHz access point and, if possible, a 5 GHz one
• Optional: external u.FL antenna for metal cases or difficult placements

1) Identify your radio module

# Puce Wi-Fi derrière sdmmc1 en SDIO (vue du device tree mainline)
ls /sys/bus/sdio/devices/
cat /sys/bus/sdio/devices/*/modalias 2>/dev/null
nmcli radio wifi                      # l'interface est-elle active ?
ip -br link                           # wlan0 (et p2p-dev / ap ?)
bluetoothctl show                     # côté Bluetooth : version LMP du contrôleur

If the module is an AP6212 (older boards), 5 GHz is physically absent — this is not a driver bug.

2) Connect (NetworkManager images: Radxa OS desktop, Armbian)

nmcli device wifi list                              # scan Wi-Fi 6
sudo nmcli device wifi connect "MonAP" password "s3cret" ipv4.method auto
ip -br addr show wlan0 && ping -c 3 1.1.1.1
nmcli -f SSID,BSSID,FREQ,IN-USE device wifi list    # vérifier la bande utilisée

3) Onboard antenna vs u.FL

The D8 module has both an onboard antenna and a u.FL connector; the antenna path is selected via software. In a plastic case, the onboard antenna is sufficient; in a metal case or far from the router, screw in a u.FL antenna and switch the selection (the option resides in the module's driver/firmware configuration — the exact method depends on the revision, check your board's module documentation). >

Expected verification

ping -c 3 1.1.1.1 reaches the Internet; iw dev wlan0 link displays the SSID, frequency, and signal strength. On a Wi-Fi 6 router, the session negotiates 802.11ax (visible on the router side). bluetoothctl lists the BT 5.4 controller (or 4.0 on older boards — a revision indicator!).

Common errors

• Looking for 5 GHz on an AP6212 board: 5 GHz channel availability depends on the module, the firmware, AND the regulatory domain — Radxa itself states that "this must be confirmed by real-world testing" (FAQ Q9).
• >
• Forgetting the software airplane mode: a forgotten nmcli radio wifi off results in an interface missing from ip link.
• Metal case without a u.FL antenna: catastrophic RSSI even though the board "gets good signal" outside the case.
• Regulatory domain not configured: 5 GHz channels unavailable; set the country (sudo iw reg set FR).
• Two boards without the correct power cable: Wi-Fi 6 transmission draws power spikes — a stingy 5 V supply causes the radio to drop under load.