A cousin of mine dropped over to my house an out of economical repair inkjet printer. HP Photosmart Plus All-in-One B209a to be exact. I dismantled it and kept the main board and the motors. While trashing the left overs I noticed the WiFi logo on one of the plastic covers. Immediately picked up the main board and there was a daughter board. I took the board out (standard 0.079″ [2 mm] pitch connector) and saw an Atheros chip. AR2524-AQ1C. I knew by heart it was an Atheros USB WiFi chip. A free WiFi USB dongle maybe? Lets find out.
The first thing I had to do was to have a look at the connector. 8 pins in total. Locating Vcc was piece of cake! Pins 1 & 2. Ground was also trivial. Pins 3,4 and 8. Pins 5 & 6 were connected to a tiny ferrite transformer, so one must be D+ and the other D- of the USB differential data bus. The only one remaining to identify was pin 7. I thought it should be something like module enable/disable pin. Pull it low/high to Enable/Disable the module or something similar. I decided to leave it unconnected.
I had also to convert the USB’s +5 volts to +3.3 volts for the module. So I bodged together a 3.3 volts voltage regulator.
The next thing to do was to find an old USB cable and bodge everything together.
Time to connect it… I immediately run lsusb. Success!
0ace:1215 ZyDAS ZD1211B 802.11g
After that I installed the z1211-firmware (Firmware for the in-kernel26 zd1211rw wireless driver). There you go. A free WiFi USB dongle. Actually I am writing this post while connected to the Internet using the salvaged WiFi card.