Raspberry Pi 3 Wifi Hackery

Robots, especially ROS ones, need Wifi connectivity. With the Raspberry Pi 3, a lot of the software/firmware level headaches are alleviated thanks to the hard work of the Raspberry Pi Foundation. However, in their efforts to keep the Pi 3 the same size, and make FCC compliance easier, they had to put a pretty wimpy ceramic “chip” antenna for Wifi and Bluetooth.

In order to get better wifi connectivity on the Pi 3, I decided to venture into finding a way get an external antenna hooked up.

If you look closely at this Pi 3, you will notice it is a bit different than the one you have. (This is my Pi, there are few like it, so this one is mine). alt text

Yup, It has an U.FL RF connector soldered onto it, (and a little charring on the mounting hole). The pi has landing pads for it, so all you have to do is get one (like I did from a dead laptop wifi card) and put it on there, and carefully move a 0201 0 Ohm resistor to a new position.

Once you spend a little too long at the reflow station trying to move the tiny resistor, you are ready to do this with your Pi. Won’t you just look at that. alt text

But what is that coax going to? Let’s zoom out a little. alt text

Oh man, another green PCB! Hanging off the side! It sticks out like a sore thumb, we need a better looking and performing antenna than this one I had lying around.

A better look at that antenna. It is mounted on a acrylic plate to lift it off the metal frame, and also allow the active element of the antenna to overhang the frame. alt text

Signal levels are about 5-10dB better at 25 feet from my AP, even with the lid on. We lose the Pi Warranty as well as the FCC and Wifi alliance certifications, but ¯\_(ツ)_/¯ for a one off…