You certainly know the problem when you lack USB ports on your laptop. A programmer in one, a logic analyzer in another, and if it is necessary to connect a serial converter, there is no place anymore, because in the last port there is a wireless receiver for a mouse. A worst situation happens when you accidentally drop your laptop and a receiver was inserted in the port and there is a problem.
Why not place a receiver inside the computer. In my laptop (Lenovo Thinkpad) I have a free Mini PCIe slot.
So I decided to build my own board. I often use a 3D mouse by 3D Connexion in addition to a normal mouse, I immediately decided on a USB hub so that I could hide two receivers in the laptop slot. The priority of the design was simplicity. There is very little space on the board, so you have to save with parts wherever you can. The decision fell on a 3-port USB hub from TI TUSB2036VF, on which I actually only used the fact that it is a HUB, I left the other features unused, there was no place for them on the PCB. In addition to the hub itself, the board also has a step-up power supply from 3,3V to 5V, since the mini PCIe only has a 3v3 power supply and some magic magic circuit. Comparator with RC circuit keeps the hub in reset after the power is turned on for a few seconds. During this time, the laptop HW check will take place and since no foreign HW is installed in laptop, the computer has no problem and everything goes well.
The device is designed on a double-sided printed circuit board, and it uses 2 middle mount USB ports. The third port from the hub is connected to a connector (maybe it will helpful in the future).
After all, photos are best to read.
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| Bottom side of PCB. |
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| Top side of PCB with receivers. |
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| USB hub installed in laptop. |
