With the release of the new Raspberry Pi Zero earlier this week we ordered one from The Pi Hut to use with our expansion boards (they all work without any problems) and one from Pimoroni to use with our barcode scanner project. There is a blog post for the Raspberry Pi Zero 2 W which was released in 2021
The new Raspberry Pi Zero W has built-in Wi-Fi and so we thought this would be better than the USB dongle which we are using with the barcode scanner.
Upon receiving the new board we noticed that the Raspberry Pi foundation has left a space and jumper pad for a U.FL RF connector to use with an external antenna.
We already had a suitable Wi-Fi antenna and so we ordered the U.FL connector and a short coaxial cable assembly from Farnell.
The parts ordered are:
On the Raspberry Pi PCB, there is a component which appears to be a zero ohm resistor (0201 size 0.6mm x 0.3mm) which links to the PCB antenna or can be turned 45 degrees to link to the U.FL connector bypassing the internal antenna.
Component to rotate
We carefully removed and rotated the resistor to the U.FL link pad and then soldered the new U.FL connector to the board.
The link rotated and the new U.FL connector was fitted.
The connector fitted to the Raspberry Pi Zero W
To test the new external antenna compared to the built-in PCB antenna we used the following command to scan for available Wi-Fi networks.
sudo iwlist wlan0 scan
The following table shows a list of networks found and their signal strength and quality readings. Most networks showed an improvement with the new external antenna and our home network had a much greater signal strength.
|Internal Antenna||External Antenna|
|Network||Channel||Encryption||Quality||Signal Level (dBm)||Quality||Signal Level (dBm)|
Testing the Raspberry Pi Zero W with the built-in antenna
Testing the Raspberry Pi Zero W with the external antenna
Please note this will invalidate the FCC certification.
The photo below shows the new modified Pi attached to the Barcode scanner project we are working on. The Raspberry Pi Zero W is mounted between the power supply/controller PCB and the touch screen so the onboard antenna would be shielded by both boards.