2019-10-22 (Tu) PirateBoxQi COMPLETED

I covered a WiFi server called PegLeg based on some hardware my friends made as an implant. The device was based on a platform called PirateBox, and while I do not plan to make my build implantable, I loved the idea of a WiFi server I could carry in my backpack.

Enough background

PirateBox.cc provided a link to compatible routers, and they were inexpensive enough that I was happy to build my own PirateBox. The installation went well, but their instructions were not always clear. Everything worked as promised. A Qi charging pad was stuck to the bottom with double-sided tape. This way, the unit could be powered just by setting it on a charging pad and powered down by picking it up. This level of convenience should make it a simple task to keep a PirateBox powered near me most of the time. Qi power banks are easy to find.
A PirateBox with a Qi charger stuck to the bottom

The exposed wire looked shabby, but the functionality was worth the breech of fashion. Unfortunately, the untethered ribbon was also fragile, and it stopped working after carrying it to work.
Bottom view

The circuitry inside the Qi pad was a coil of lacquered magnet wire and the interposing charging circuit. This charging circuit received the raw voltage from the coil and rectified it to a usable and consistent voltage suitable to powering and charging portable devices. The black surface behind the coil was a ferrite pad necessary for harvesting power. The cause of the failure was not apparent so the hardware was a loss. This was an inexpensive impulse buy from a long time ago. Nothing of significance was lost, aside from time.
Inside a faulty Qi charger

Anyone who wants to copy this project should read to the end before attempting anything since I attached power in the wrong place on the first try. Nothing smoked, but you will save time by reading to the end.

I had another Qi charging pad, so this time I decided to try to fit the charger inside the case and make it look cleaner and less prone to damage. The first step was to find where 5V was available so I could send it voltage from the charger. The most readily apparent place was the USB receptacle where my flash drive usually went. The component used a through-hole footprint, so accessing it from the bottom was easy. Sure enough, I found five volts on the USB pins.
Finding 5V on the USB port

The second Qi charger was opened. These inexpensive modules were raw components stuck between two mated pieces of printed tape. On one of them, the ferrite pad was black, and on the other, it was silver. The silver-colored one was a flaky metal that felt awful when I cut it with scissors, but it worked. Do not remove these. The PCBs were oriented differently, as well.
Different ferrite shields and PCB orientations

The ribbon running to a micro USB plug was removed, and thin insulated wire was soldered in place. The ground wire was blackened with a marker to keep it distinct. This ribbon may be useful in the future, so it will be kept handy.
New wires on the Qi output

A portable Qi-enabled charging bank provided power to the coil, but the device would not power on. To verify that power was working, a USB diagnostic stick was plugged into the PirateBox and showed that some voltage was present.
Voltage only on the USB port

There was circuitry keeping the USB plug from back powering the rest of the device while providing power. It would function to plug a USB cable into the socket and use that to run the everything, but that would mean I could not use the USB port, plus it would look awful.
Hackiest way to power a PirateBox?

Getting voltage right to the incoming power terminals would be ideal, and I even had a micro USB breakout board with labels, so finding the correct pin was arbitrary. It was the top one in the picture. Unfortunately, the pin was impossible to reach with a bulky soldering iron tip and so tiny that any wire would break away with a light twist.
Pinout on micro USB

I consulted a teardown of the AR150 to find raw power, and it helped, but I still needed a good deal of hunting finally revealed an accessible point where I could solder incoming power. The sides of C23 were the positive and negative incoming power, so it was a power filtering device. Its size made it easy to add a couple of small wires securely. The back of the ferrite layer was covered in tape to prevent shorts, and the charging board was similarly coated.
Power wires around C23 on board GL-AR150-V4.4

A small plastic tab on the bottom panel had to be removed so everything could be closed back up. Flush cutters removed the stud immediately.
Remove the plastic tab

The best place for the coil and charging PCB was the corner opposite the air vent, which is also where the onboard antenna traces were.
The best location for a coil

After everything was sealed up, my phone and computer connected and were chatting with each other in no time.
Everybody talks

Arguably the most imparative step, I decorated the box with stickers. The green wireless symbol was salvaged from the Qi charger as well as the “Wireless Charger” sticker. Of course, a Hackaday sticker made its home there, but three holes had to be punched in it so the lights would be visible during operation.
The stars increase the top speed, that's just science

A second charging base was tested. I thought this base was defunct, but it may just have a malfunctioning light. It got warm, which may have been a problem with how the coils were misaligned.
Light show

First time here?

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Completed projects from year 6

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