Troubleshooting • Configuring Fixed Frequency and Bandwidth on Raspberry Pi CM4 for 2.4GHz WiFi

Configuring Fixed Frequency and Bandwidth on Raspberry Pi CM4 for 2.4GHz WiFi
Hello everyone,

I recently encountered an interesting issue while working on setting up a fixed frequency for 2.4GHz WiFi on my Raspberry Pi CM4. Specifically, I found that while the fixed frequency signal works perfectly on a 20MHz bandwidth under the 'n' protocol, the same configuration does not work for a 40MHz bandwidth. In this blog, I will share my setup process, the issues I faced, and the troubleshooting steps I undertook.

Hardware and Software Setup

Hardware:

Raspberry Pi CM4
WiFi module compatible with Raspberry Pi CM4

Software:

Raspberry Pi OS 2024 2023-02-21-raspios-bullseye-armhf & wl.iw


the following script can work normaly:
the following script will return an error 20 in chanspec :
wl -i wlan0 out
wl -i wlan0 down
wl -i wlan0 frameburst 1
wl -i wlan0 ampdu 1
wl -i wlan0 country CN
wl -i wlan0 bi 65000
wl -i wlan0 phy_watchdog 0
wl -i wlan0 mpc 0
wl -i wlan0 txchain 1
wl -i wlan0 mimo_bw_cap 1
wl -i wlan0 band b
wl -i wlan0 chanspec -c 3 -b 2 -w 40 -s 1
wl -i wlan0 2g_rate -h 0 -b 40
wl -i wlan0 up
wl -i wlan0 disassoc
wl -i wlan0 phy_forcecal 1
wl -i wlan0 scansuppress 1
wl -i wlan0 txpwr1 -o -q 70
wl -i wlan0 pkteng_start 00:11:22:33:44:55 tx 20 1500 0

Statistics: Posted by qqdyta — Wed Jul 03, 2024 8:37 am

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