The Situation
I had actually bought a flexible keyboard from the market and i had no idea that it had a USB socket to the output. I was using this USB keyboard for a couple of days and after using it for some time it was giving me trouble. Sometimes the keys did not function properly and sometimes it would automatically eject i.e disconnect from the computer port and again connect. I was having such problem and decided to find a solution for it.
The conception
After doing a bit of research i found out that most of the modern keyboards can be easily adapted to a PS/2 connector with ease. The only thing you need is just the USB socket and a PS/2 Jack (i got mine from an old mouse of mine). I also found out that when you buy a keyboard and if it is for the long run like in a Personal Computer, then it is better to have a PS/2 connector bought. Since the flaws for buying a USB keyboard are (i) It is gonna occupy one of the USB slots in your computer and hence there will be no space for USB when you are connecting multiple com ports. (ii)It is gonna use some kind of processor time since it has plugged into a USB. Very nice to have one more empty USB connector
Therefore my suggestion for you all if you are buying for a Personal Computer is to buy a PS/2 keyboard in place of USB. But again if you have already bought it then this instructables is gonna teach you how to accomplish the feat.
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Signing UpStep 1The Project
1. USB SOCKET 1 PCS
2. PS2 JACK 1 PCS
3. CABLE HAVING 4 WIRES. (ANY)
Then the only thing you have to do is see the circuit diagram that i have submitted here and solder the wires according to the pins. You are then done.
Your USB keyboard will be hooked to a PS/2 converter and will work just fine.
It should also be noted that some old keyboards will not work as the parts used inside the old keyboards will not generate the required cock timings required for the motherboard to comply with it.
But most of the Keyboard will definitely work.
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thank you!
marC:)
Then simply follow the circuit diagram that i have given in the instructable. Many manufactures use different color of wires but you can check it with a simple multimeter and find out the pin outs where these wire lead to.
If you look at the diagram that i have posted you can easily connect the keyboard.
thank you!
marC:)
And there are only 4 wires so it will definitely be an easy one.
It is when you try to go from a PS2 connection to a USB port. That requires a much more complicated converter in order to process the signal.
I don't know if I have anymore of the PS2 to USB converters, but if I can find one I will post pics so you can see the difference.
The PS/2 keyboard is like I2C serial device. It has clock and data lines.
The hardware inside a PS/2 keyboard doesn't have capabilities to emulate a USB HID device as a USB keyboard.
Hence USB will give message device not recognized.
I think you have not read my instructables properly. I have already mentioned in my instructable that only some recent usb keyboard can be adapted for this method. And for your information i have already tested in my PC and it is working 100%. you can see the pictures in the instructables given.
And thanks for you comment
Otherwise, theoretically it seems impossible because of different topologies in these two types of keyboards, which prevent them from interchanging interfaces (USB to PS2, or vice versa).
Anyway, thanks for writing a detailed instructable.