Laptop modding: install usb on mini PCI-e

Hey guys,

some time passed, but still some hot stuff for you. If you have a laptop, you've experience the "damn, no free USB... it s*cks". I'm sure that of course all the small sticks that hang out from your laptop case are in terrible danger or feel uncomfortable... I have the solution... obviously not for everybody... be sure you have an idea of what you're doing...

We are talking about installing a usb device inside your laptop, without loosing free usb outside. Things you must know:

• If you do the wrong thing you may f*ck your box
• You need some space enough to make the device fit in the case
• you need to solder... really tiny stuff...

But let's reveal the most interesting news: you have a free usb under your wifi card. Yeah, that's it... pcie ports contain one usb port each.
Let's introduce the usb standard:

Pin	Name	Cable color	Description
1	VCC	Red	+5 VDC
2	D-	White	Data -
3	D+	Green	Data +
4	GND	Black	Ground

If you want to know more (look at pin disposition) here. While VCC is the alim line and GND is the ground, there are two channels for data, used to communicate serially. Looking at the mini PCIe:

Top side		Bottom side
1		2	3.3V
3	Reserved****	4	GND
5	Reserved****	6	1.5V
7	CLKREQ#	8	Reserved**
9	GND	10	Reserved**
11	REFCLK-	12	Reserved**
13	REFCLK+	14	Reserved**
15		16	Reserved**
Mechanical key
17	Reserved	18	GND
19	Reserved	20	Reserved***
21	GND	22	PERST#
23	PERn0	24	+3.3Vaux
25	PERp0	26	GND
27	GND	28	+1.5V
29	GND	30	SMB_CLK
31	PETn0	32	SMB_DATA
33	PETp0	34	GND
35	GND	36	USB_D-
37	Reserved*	38	USB_D+
39	Reserved*	40	GND
41	Reserved*	42	LED_WWAN#
43	Reserved*	44	LED_WLAN#
45	Reserved*	46	LED_WPAN#
47	Reserved*	48	+1.5V
49	Reserved*	50	GND
51	Reserved*	52	+3.3V

Looking at the 36 and 38 pins... whoa! here it is. The most interesting thing is that usually no wifi card uses this port, thus it stands here unused. The missing stuff is just the alim: I suggest to connect two USB port 5V contact together (of course from the inside) and solder there the source of your VCC: this will share the load on the ports preventing the overcurrent drain.

You can connect there whatever you want, but follow these few advices:

• work on power off, and double check everything before giving power
• use always a multimeter
• open the device box and unsolder the USB tip pad by pad: if you break it you'll feel damned stupid
• double check if the device fits before apply any mod to the case
• use a VERY SMALL TIP SOLDER and do not solder miniPCIe on the pads: they will shortcut immediately, use the climbing wires of the connector, as in the bottom picture
• use the shortest wire you can and the smallest amount of tin you can, if needed use a smaller couple of wires to take out the connection
• twist the data wires if they run for more than 3-4 cm

your result should look like this:

WARNING: some USB drives needs fast connection! long cables with poor shielding will cause unstable link!

In my case the installed stuff is not only the USB receiver of my wireless desktop set, but also a switch to activate and deactivate it when needed. I'll post about it in the feature.

If you have a question leave a comment please, I'll answer surely!

Cheers