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RedskullDC

USB HID -> PS/2 PMOD board ?

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Hi Digilent staff, and fellow forum members,

Just wondering if you guys had considered making a USB HID -> PS/2 PMOD board? 
 
I was thinking of something like the circuit on the Nexys 3,4 boards which 
uses a PIC to convert a USB keyboard to PS/2 compatible signals.

Would be handy for using newer USB keyboards/mice on PMOD socket equipped FPGA boards.

PS/2 devices are becoming harder to find brand new.
 
I (for one) would be interested in a few. 
 
Kind regards, 
Leslie 

 

Edited by Josh
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Hi Leslie,

That's an interesting idea! I have been considering a Pmod that took a USB input and turned it into a compatible Pmod header format. 

The USB to PS/2 would be different though since you would still need the header pins (the 6 or 12 pins) so that way it could plug into a Pmod port, effectively making it have three different header types on one board which you don't see too often.

Are you wanting to use the older PS/2 communication style rather than trying to work with USB (since USB is significantly trickier to work with)?

Thanks,
JColvin

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Hi JC,

Thanks for your response.

Sorry, should have been more specific.

I was thinking of a PMOD board which basically incorporates the USB HID circuitry as implemented on the NEXYS 3 and 4 boards with a PIC24FJ192 .

>Are you wanting to use the older PS/2 communication style rather than trying to work with USB

Exactly. There is a great deal of code projects out there written to take PS/2 Mouse/Keyboard signals.

Such a PMOD board would allow those projects to be used "as-is" without having to implement USB in the FPGA.

Kind regards,

Leslie

 

 

 

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Leslie,

If I understand correctly, you want to use the Nexys 4 or 3 USB port with PS2 signals. 

You can do this as is. If you go to the section of the reference manual for the Nexys 4 to the USB HID section you can see that the microcontroller emulates old style PS2 signals.

The Auxiliary Function microcontroller hides the USB HID protocol from the FPGA and emulates an old-style PS/2 bus. The microcontroller behaves just like a PS/2 keyboard or mouse would. This means new designs can re-use existing PS/2 IP cores. 

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 Hi Kaitlyn,

If I understand correctly, you want to use the Nexys 4 or 3 USB port with PS2 signals. 

No, my request has nothing to do with the Nexys3 or 4, I don't have either.

I would like to see a PMOD board which takes a USB Keyboard/mouse input, and converts that to PS/2 compatible signals on the normal 6/12 PMOD style header pins.

Basically, the same USB HID circuitry which already appears on the NEXYS3/4 boards, but on a PMOD board. Shouldn't be too difficult.

I would like to be able to use a USB Mouse/Keyboard on other PMOD equipped FPGA boards which *don't* have the USB HID circuitry. Nexys2 for example.

Hope that's a bit clearer :)

 

Cheers,

Leslie

 

 

 

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Hi Leslie,

I think I know what you're going for. Although we don't have the direct USB to PS/2 Pmod, we do have a Pmod similar to that, the PmodUSBUART. It doesn't send strict PS/2 signals, but rather in the UART convention. I personally don't know how well it would handle commands from a keyboard/mouse and it doesn't have the USB type A connector that most keyboards and mice use, but I imagine there are conversion cables that exist out there.

Although I do agree that the direct USB to PS/2 in the 6 or 12 pin configuration Pmod would be pretty cool to have.

Let me know if you have any questions.

Thanks,
JColvin

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On 19/08/2015 at 8:27 AM, JColvin said:

Although I do agree that the direct USB to PS/2 in the 6 or 12 pin configuration Pmod would be pretty cool to have.

Thanks,
JColvin

Hi JC,

Ever given any more thought to this idea?

PS/2 keyboards are becoming ever-increasingly difficult to find new.

It would be great to be able to plug a new USB keyboard in to a PMOD and just treat it as a PS/2 model from my code.

Alternatively, would you consider releasing the PIC24 code you used on the NEXYS 3/4 boards to do the USB>PS/2 conversion so that users could build their own without having to re-invent the wheel?

Best Wishes,

Leslie

 

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Hi @RedskullDC,

Unfortunately, we have not yet developed such a product at this point in time. We do have a have a product manager specifically for Pmods now (which was not the case when this thread was created), so I will get this request to them. I'll give an update later if I can, but it may be some time (i.e. months) before I am aware of any development status for such a product.

Thanks,
JColvin

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I would love to see a PMOD USB to HID that could work as either a controller (takes input from HID devices) or as a slave (meaning, it acts like a keyboard or mouse)

The pro micro arduino does this and I have one.  It's pretty great, but not in a PMOD format.

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