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Electronics => Projects, Designs, and Technical Stuff => Topic started by: binary_99 on April 30, 2018, 10:30:26 pm

Title: Wifi adapter (mini PCIE) to PCIE X1 schematic
Post by: binary_99 on April 30, 2018, 10:30:26 pm

Hi all,

Long time Dave watcher, first time poster.

As the title says, I'm looking for advice or a schematic to make my own mini PCIE to PCIE X1 adapter for a wireless card. I know they can be bought off Ebay for less than $10, but, for sh!ts and giggles I'd like to etch my own board to fit into the PCIE X1 slot on my computer (plus I'd like not to have to wait 8 weeks for it)

I made a board based on the schematic from this site https://boundarydevices.com/wp-content/uploads/2014/12/PM2-C.pdf (https://boundarydevices.com/wp-content/uploads/2014/12/PM2-C.pdf) and......it doesn't work. There are resistors and talk of capacitors for the Tx/Rx lines but do not give details of values.

If anyone is able to give any assistance I would much be appreciative. I don't need the USB port or LEDS, I just would like the bare bones to get the wireless card to work in my computer.

Thanks!

Title: Re: Wifi adapter (mini PCIE) to PCIE X1 schematic
Post by: ANTALIFE on April 30, 2018, 11:28:02 pm

Can you give us a picture of the board you made?

This project would be dealing with some "high-speed" signals so your board design would need to take things like impedance matching & trace lengths into account

Title: Re: Wifi adapter (mini PCIE) to PCIE X1 schematic
Post by: binary_99 on April 30, 2018, 11:55:34 pm

Thanks for the reply ANTALIFE,

Yeah, the length matching. I did it to the TXp and TXn lines, but neglected to do it on the RX lines so they were out by about 100mils or so. I don't think that was the issue with it not working at all though?

This was a project I was hoping I could just Google and find a layout someone else had done. Imagine my surprise.

I'll attach the PCB layout, but please forgive my barbaric crudeness. I only did one via and the others I needed to do I just went around the edge of the board.....don't laugh! lol I also have some jumpers on there to cross traces......don't laugh!

Title: Re: Wifi adapter (mini PCIE) to PCIE X1 schematic
Post by: binary_99 on May 01, 2018, 12:04:55 am

And just for further information. I installed a jumper wire on the motherboards pcie x1 slot from PRSNT1# to PRSNT2#.

Title: Re: Wifi adapter (mini PCIE) to PCIE X1 schematic
Post by: Bratster on May 01, 2018, 01:58:57 am

Are you sure your WiFi card is actually pcie?

I'm pretty sure the mini pcie port has usb as well, so the card may use that.

Sent from my Moto x4 using Tapatalk

Title: Re: Wifi adapter (mini PCIE) to PCIE X1 schematic
Post by: Monkeh on May 01, 2018, 02:29:05 am

That layout is just not going to work for PCIe.

It's really not practical to do this with a home etched board.

Quote from: Bratster on May 01, 2018, 01:58:57 am

Are you sure your WiFi card is actually pcie?

I'm pretty sure the mini pcie port has usb as well, so the card may use that.

Very unusual and unlikely.