WLAN
Here you can either connect a WLAN rod antenna directly or an external antenna via an appropriate antenna cable. When selecting the antenna, note that the antenna connection is implemented as an RP-SMA socket (“reverse polarity”).
The WLAN interface operates at 2.4 and 5 GHz and complies with the IEEE802.11a/b/g/n/ac specification. It is included on the Compute Module 4. A Cypress CYW43455 (formerly Broadcom BCM43455) WLAN/BT chip is used.
Under Linux you can address the interface as “wlan0” (by default, without other WLAN devices).
Enabling WLAN
To use WLAN and BT, you have to enable it once in the basic configuration of your RevPi:
- Enable WLAN via Cockpit.
- Enable WLAN via RevPi Status.
Configuring WLAN
You can configure the WLAN interface via the command line as follows.
- Enter the following command to search for networks in the vicinity:
sudo iw wlan0 scan
- Use the following command to connect to an unencrypted network:
sudo iw dev wlan0 connect <YOUR ESSID>
- Enter the following command if you want to display the link status:
sudo iw dev wlan0 link
Setting up WLAN via the Command Line
The “wpa_supplicant” tool can configure network interfaces and establish a connection to wireless networks. You can read how to set up WLAN on the RevPi Connect 4 via the following link in the section “Adding the network details to the Raspberry Pi”.
Setting up WLAN via the Command Line Tool nmtui
Starting with the image version Bullseye you can also use the command line tool nmtui. This manages the network connections via the NetworkManager.
BT
A BT interface is also available via the same SMA socket as for the WLAN interface. It complies with the BT standard 5.0 and is connected to the Compute Module 4.
Configuring BT
- Enter the following commands to connect a serial UART to the BT stack as an HCI transport interface::
sudo systemctl enable hciuart
sudo systemctl start hciuart
- Start the BT Daemon with:
sudo systemctl start bluetooth
BlueZ is the BT system for Linux that allows a RevPi Connect 4 (Raspberry Pi) to communicate with classic and low-energy BT devices.
„bluetoothctl“ is the command line interface to BlueZ.
- Enter
bluetoothctl -v.
If you want to configure BT devices with “bluetoothctl”, you can find more information on Linux Magazine.