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PS/2 to USB converter for BOTH keyboard and Mouse

Former Member

We are looking to design a PS/2 to USB converter for both a Keyboard and Mouse interface. We have experience with the USB via FTDI chips but no experience with the PS/2 interface. We are looking for a single chip solution that will be able to handle both the mouse and keyboard interface. What are the options available ? We really need a chip that will handle the USB side of things seamlessly - else wise we will need to to a FTDI solution and possibly an additional chip.

 

The mouse and keyboard are PS/2 and the USB output is into a PC with OS Windows or Linux.

  • There are many adapters out there that cost just a few $.

    If you need to roll your own, you could check what chips they use......

    image

  • in reply to dougw

    More than likely it is a low power micocontroller (PIC, AVR, etc.) with a built in USB interface.

  • in reply to dougw

    Douglus,

     

    We have looked into these but we need an adapter that can work at extended temperatures e.g. -40 deg C to +85 Deg C - which we were not able to find.....

  • in reply to gdstew

    Gary,

     

    Do you or anyone else know of any specific designs e.g. using these types of chips for this functionality ?

     

    Shmuel

  • in reply to shmueld

    Shmuel,

     

    I don't know of any chips specifically designed for this and I doubt there are any because it is relatively easy to do with a microcontroller.

    I did a quick internet search for PIC PS2 keyboard, PIC PS2 mouse, AVR PS2 keyboard, and AVR PS2 mouse and came up with several

    examples for each. Licensing the code found on the internet for your use may (or may not) be a problem but you should make sure

    before you use it. For non-commercial use it would probably not be hard to find code you could use. From what I'm understanding from

    your posts you intend to use it for commercial purposes and this means you should always check first.

     

    I checked and both microcontrollers are available in the industrial temperature range that you need.

  • in reply to gdstew

    Dear Gary,

     

    Thanks for getting back to me.

     

    We have no experience with PIC nor AVR microcontrollers. In all our USB projects we have used FTDI based chips to do the USB interface.

     

    How is the USB interfaced to and from the PIC \ AVR ICs ? Is there any firmware development involved or is it a standard feature of this ICs and then I will only need code for the PS/2 Keyboard \ mouse interface ?

     

    Best regards

     

    Shmuel

  • in reply to shmueld

    Shemuel,

     

    I believe both of these manufacturers have USB libraries available, some free to use and keyboard and mouse interfaces are a fairly common

    application for demonstrations of their chip interfaces. Again a web search will probably find some useful examples/information.

     

    If you have any experience with other micrcontrollers neither one of these is too difficult to migrate to with the AVR probably being the easiest.

    PICs have a more complicated register/memory architecture and lots of internal configuration options and so a bigger learning curve. My guess

    is that PICs are favored for applications like this mainly due to low cost/power and good bit-bang interface capabilities. To make things a little

    strange, a few years ago Microchip which makes the PICs bought Atmel which made the AVR so both of these now come from the same company.

     

    You might want to look into the Arduino family of boards to see if any of them could be used as a prototype platform for your application. They

    have a good IDE tool set for writing C(++) code and a large number of libraries available for all kinds of interfacing. The tool set and libraries

    are free. I don't know of any PIC equivalent platform (I wish there was one) but I am sure they have evaluation boards and development software

    available. There are also free C and assembly tools available for the PIC.

     

    Gary

  • in reply to Former Member

    Thermal performance of electronics is a big subject and there also is a lot of misinformation to be wary of.

    It may be feasible to "up-rate" a part if you test it adequately for your application. Many companies do this successfully.

    Intel and AMD might not make military versions of their chips and yet their chips often end up in military systems (after rigorous testing)

    It may also be feasible to "up-rate" a part by adding a conformal coating, but such measures take more in depth knowledge and testing to ensure adequate performance.

    https://www.electronics-cooling.com/2004/02/the-temperature-ratings-of-electronic-parts/

  • in reply to dougw

    Or you could just buy parts with the standard industrial temperature range that Shmuel is looking for. A lot of parts come that way, no extra charge.

    The ones that cost more usually don't cost a lot more and are already tested so you don't need to spend money for upgrade testing or coating them.

    The only thing that needs to be done is to make sure the design really needs the extended temperature range.

  • in reply to gdstew

    Dear Gary,

     

    Thank you so much for your response - you clarified a lot for me ! We are in the process of deciding on which track to take.....

     

    Bests regards

     

    Shmuel