Turning a ps2 keyboard from 2002 into a usb keyboard with built in storage. Possible?

[SimplySteak]

Hello there,

So, as the title says I have the idea of turning the old ps2 keyboard I got from my uncle into a keyboard that has the ability to also store data for me.

I guess that I'll probably have to strip the PS2 cable into a shorter version of it. Then either plug that ps2 into a small processor/hub which combines (I know, the wrong word, but I don't know every single term... I am a semi-hobbyist) the signals from the keyboard with the in and output of the storage drive (I'll probably be going for an SSD due to the size of it, or a flash USB drive?

I know that all of what I just said is probably just dumb-man talk. But that's why I'm here.

Now I know a bit of soldering, the same uncle as before will teach me more of it this summer. I have some DIY skills and happy to learn so that won't be a problem.

I live in Europe, and wouldn't even know where to get the needed parts, except the storage drive maybe.

 

Hopefully, somebody can help me. Any help appreciated
Greetings,

Steak

 

PS: A picture of the type of keyboard plus (inside behind the metal backplate and seethrough electronics)

[mariushm]

2$ : USB to PS/2 keyboard+mouse: https://www.ebay.com/itm/Converter-Adapter-Cable-USB-Male-to-2-PS2-Female-Keyboard-Mouse-Y-Splitter/163195591687?hash=item25ff371c07:g:k~kAAOSwn6dbbXcY

 

You need this to actively convert the PS/2 signal to USB data packets. There are cheaper adapters like this one, but these may or may not work with hubs, they may only work when plugged directly into the motherboard IO shield.

 

 

You can use a very sharp blade to cut the plastic from that piece in the middle, to remove the case and make it thinner, and also to solder the wires from the keyboard directly to the keyboard ps/2 input (where the wires from the mauve connector are soldered to the tiny circuit board) and you can then also solder the 4 wires of the usb directly to one of the usb ports the usb hub below creates.

 

Step 2 : usb hub as a circuit board: takes in one USB and creates multiple USB ports... you need one port for the keyboard, one for the USB stick or USB drive you hide inside the keyboard and optionally you can add extra usb connectors for example to plug mouse usb cable into the keyboard.

 

Here's an example: https://www.ebay.com/itm/Motherboard-USB-9-Pin-Header-Splitter-1-to-4-Extension-Cable-Port-Multiplier-HUB/142899073533?epid=14022395056&hash=item214572d1fd:g:NnMAAOSwT-FcpgUb

 

 

There's two boards (they can be separated in the middle), each with a hub IC that creates 4 usb ports (the two black headers) from a single usb port

You can desolder the headers to get the height very low and solder wires directly - the pinout is standardized : http://www.hobbytronics.co.uk/usb-connector-pinout

You can also desolder the capacitors and replace them with through hole ones to lay them horizontally for lower height, if that's critical. Surface mounted ceramic or tantalum capacitors would also work

 

 

You can connect a usb stick inside to one of the other usb headers, or a usb to sata/msata adapter board (to plug a ssd in it if there's room)

You'll be left with two other usb ports (a header with 2 sets of pins) that's unused ... you could drill a couple of holes in the back of the keyboard for a couple of usb ports ... here's an example.

 

All that's left is a usb cable .. that's easy... literally any usb extension cable ... cut one end and solder wires directly to the usb hub.

example

1: https://www.ebay.com/itm/3m-10ft-USB-2-0-Type-A-Male-to-A-Female-Super-Speed-Extension-Cable-Adapter-Blue/153326510858?hash=item23b2f8e30a%3Am%3AmwvsIuZb0H74H6epflhTMWw&LH_BIN=1

2: https://www.ebay.com/itm/0-3-1-5-3m-USB-2-0-Extension-Cable-A-Male-to-A-Female-Data-Cord-5Gbps/362524276950?hash=item54682178d6%3Am%3AmHAfG-i4q3C74Q6w3EKTBrw&LH_BIN=1

 

or actual usb cables (but you pay shipping as well) : https://www.digikey.com/short/pb79fc

 

ps. and if needed you can add a switch somewhere to turn off power to the internal usb stick, so it won't be visible in Windows ... a simple slide switch to connect the 5v wire or not (and optionally ground if double side double pole slide switch is used) would be enough

 

[SimplySteak]

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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 Advanced issues found

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1 hour ago, mariushm said:

2$ : USB to PS/2 keyboard+mouse: https://www.ebay.com/itm/Converter-Adapter-Cable-USB-Male-to-2-PS2-Female-Keyboard-Mouse-Y-Splitter/163195591687?hash=item25ff371c07:g:k~kAAOSwn6dbbXcY

 

You need this to actively convert the PS/2 signal to USB data packets. There are cheaper adapters like this one, but these may or may not work with hubs, they may only work when plugged directly into the motherboard IO shield.

 

 

You can use a very sharp blade to cut the plastic from that piece in the middle, to remove the case and make it thinner, and also to solder the wires from the keyboard directly to the keyboard ps/2 input (where the wires from the mauve connector are soldered to the tiny circuit board) and you can then also solder the 4 wires of the usb directly to one of the usb ports the usb hub below creates.

 

Step 2 : usb hub as a circuit board: takes in one USB and creates multiple USB ports... you need one port for the keyboard, one for the USB stick or USB drive you hide inside the keyboard and optionally you can add extra usb connectors for example to plug mouse usb cable into the keyboard.

 

Here's an example: https://www.ebay.com/itm/Motherboard-USB-9-Pin-Header-Splitter-1-to-4-Extension-Cable-Port-Multiplier-HUB/142899073533?epid=14022395056&hash=item214572d1fd:g:NnMAAOSwT-FcpgUb

 

 

There's two boards (they can be separated in the middle), each with a hub IC that creates 4 usb ports (the two black headers) from a single usb port

You can desolder the headers to get the height very low and solder wires directly - the pinout is standardized : http://www.hobbytronics.co.uk/usb-connector-pinout

You can also desolder the capacitors and replace them with through hole ones to lay them horizontally for lower height, if that's critical. Surface mounted ceramic or tantalum capacitors would also work

 

 

You can connect a usb stick inside to one of the other usb headers, or a usb to sata/msata adapter board (to plug a ssd in it if there's room)

You'll be left with two other usb ports (a header with 2 sets of pins) that's unused ... you could drill a couple of holes in the back of the keyboard for a couple of usb ports ... here's an example.

 

All that's left is a usb cable .. that's easy... literally any usb extension cable ... cut one end and solder wires directly to the usb hub.

example

1: https://www.ebay.com/itm/3m-10ft-USB-2-0-Type-A-Male-to-A-Female-Super-Speed-Extension-Cable-Adapter-Blue/153326510858?hash=item23b2f8e30a%3Am%3AmwvsIuZb0H74H6epflhTMWw&LH_BIN=1

2: https://www.ebay.com/itm/0-3-1-5-3m-USB-2-0-Extension-Cable-A-Male-to-A-Female-Data-Cord-5Gbps/362524276950?hash=item54682178d6%3Am%3AmHAfG-i4q3C74Q6w3EKTBrw&LH_BIN=1

 

or actual usb cables (but you pay shipping as well) : https://www.digikey.com/short/pb79fc

 

ps. and if needed you can add a switch somewhere to turn off power to the internal usb stick, so it won't be visible in Windows ... a simple slide switch to connect the 5v wire or not (and optionally ground if double side double pole slide switch is used) would be enough

 

Wow, thanks yeah most of these items should work in the tight space (I checked). I'm probably going to check eBay some more for like-wise items as one of the items is sold by someone who doesn't sell to Europe. I'll probably post further updates to this little project of mine (I know it ain't much, but we all have to start somewhere.)

 

1 hour ago, James Evens said:

Looks like you are space constraint. 

You could try a tiny usb hub (for example from crowd supply), microSD reader and µC or prebuild PS2 adapter. Could be that you are limited due to the hub to usb 2.0

I have around 1,5 millimetres of space in height, which goes down to 0,5 millimetres around 7 centimetres further in length. I can also use a Dremel to take out some plastic struts which will give me more room in width, without compromising too much integrity of the bottom part of the keyboard. I'll keep in mind your solution when I've Dremeled out the plastic and reviewed the possible dimensions.

[SimplySteak]

13 minutes ago, James Evens said:

Those aren't ideal as they will need rework:

- large pcb size

- large connector height + cable make it impossible to place inside a keyboard

 

In the past i used such designs: https://www.tindie.com/products/mux/nanohub-tiny-usb-hub-for-hacking-projects/

 

did you mean 1,5 cm not mm? If we are talking about mm you need to pull off a complete DIY solution: thinnest PCB you can get (maybe 0.6mm could work), sanding down the IC/package, maybe placing capacitors in cutouts and using micro SD or usb flash drives won't work as they are thicker then 1.5mm.

... yeah, I'm dumb, I meant 1,5 cm...I thought I wrote it correctly, but I missed that...

Mhm okay, well if I can solder the cables onto the PCB board, then the height issue might be fixed? Especially if I could take out the plastic shielding of the female ports, or grind them down.

[mariushm]

21 minutes ago, James Evens said:

Those aren't ideal as they will need rework:

- large pcb size

- large connector height + cable make it impossible to place inside a keyboard

 

In the past i used such designs: https://www.tindie.com/products/mux/nanohub-tiny-usb-hub-for-hacking-projects/

 

The big board can be cut in the middle with a guillotine or even some big scissors (the kind used for gardening) IF they don't already have v-scoring in the middle.

If there's v-scoring, you can just break them apart by bending the board in the middle.

 

You can desolder the headers and plastic shroud falls out and you can then solder wires directly in the through holes to reduce the height. Already said this.

Then if you only need 2 usb ports, you can further cut it, as the orange lines show (the traces going to the header can be simply left floating, as long as they don't touch each other it would be fine.

To reduce width even further, you could go as far as removing the ground wire and soldering the ground directly to ground fill or ground of the input capacitor which can also be changed to a ceramic capacitor or electrolytic layed flat to reduce height and to give you ability to cut pcb right below the pads of that capacitor.

The two tiny ceramic resistors can be an issue, but you can look on the bottom side to see where those traces go and in theory a bit of magnet wire could be used to solder those resistors directly to pins of the IC.

So the board is already 2.5cm by 5cm and you can shrink it more. Height pretty much as big as that oscillator ... plenty of room in the keyboard to fit.

 

So yeah... it's ~5$ for 2 x 4 port usb hub, or 10$ for a nano-hub with 2 ports ... if you really need the nano size then it may be worth it.

 

 

Alternatively, you could actually just buy the usb hub chip, it's 0.5$ : https://lcsc.com/product-detail/USB_GENESYS_GL850G_GL850G_C14869.html

Datasheet is here: https://www.kean.com.au/oshw/WR703N/GL850G USB Hub 1.07.pdf

You can buy one of the boards below and just use a multimeter to measure the resistors and capacitors and make your own circuit boards afterwards in whatever layout you want.