This should be doable with an inexpensive AVR fob.

Should work fine, but using a raspberry pi for this is kind of overkill, but hey, it is up to you.

gdjacobs wrote:

This should be doable with an inexpensive AVR fob.

Such as? I am unfamiliar with AVR fobs.

The Teensy is a very small Atmel AVR board. In combination with the firmware payload Matze made for his converter and a MAX232 style level converter, you'd have a cheap and easy way to prototype your own interface.

Looks like the cheapest I can get a Teensy is $19.50 (+ shipping?) And that is for the v3.2 Or am I not seeing a much cheaper option?

I can get a Raspberry Pi Zero for $9.55 shipped.

In any case, somebody is going to be giving me an old Raspberry Pi to play with.

There is also code and schematics to make a PS/2 to serial adapter using an arduino board.
https://youtu.be/R_H84iGJeDo
https://github.com/Lameguy64/ps2serial

I think USB would be much more useful in the long run.

Would one of these be viable to use?
https://www.ebay.com/itm/STM32F030F4P6-CORTEX … B-/142756611303

cyclone3d wrote:

So while mulling over the fact that the only serial pointing devices I have are trackballs, I came across this program for Raspberry Pi that acts as an active converter to let you use a USB mouse on a serial port.

I'd considered doing exactly this a year or so ago but realized I'd need to wire up the Pi's UART along with a GPIO pin to act as RTS (used to reset the 'mouse') through an RS232 transceiver so nothing ever came of it.
Only now does it occur to me that I could have just used one of the USB<->RS232 adapters that I already have 😵

It's nice to see that someone already wrote the software, though; I've got a couple of original Pis gathering dust that would be appropriate for such a purpose. I suppose they could be considered overkill but they can always do other things at the same time like act as a file server using EtherDFS or something. Plus it amuses me that they could probably emulate most of the systems I'd want to attach a serial mouse to but I'd be using them for such a menial purpose instead 😀

cyclone3d wrote:

Looks like the cheapest I can get a Teensy is $19.50 (+ shipping?) And that is for the v3.2 Or am I not seeing a much cheaper option?

I can get a Raspberry Pi Zero for $9.55 shipped.

In any case, somebody is going to be giving me an old Raspberry Pi to play with.

Don't get me wrong, Raspberry Pi boards are fun. It just seems wasteful to run a bunch of OS to emulate a serial mouse. 😒

Looks like Arduino Nanos are the most inexpensive option for AVR micro dev boards. It should be fairly straightforward to move from Matze' work to that, and the uC itself will run < 5 USD.

Just remembering that you don't need to buy the original Arduino board, since it is all open source you can get cheap clones from china and they will work well.

cyclone3d wrote:

There is also code and schematics to make a PS/2 to serial adapter using an arduino board. https://youtu.be/R_H84iGJeDo https:// […]
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There is also code and schematics to make a PS/2 to serial adapter using an arduino board.
https://youtu.be/R_H84iGJeDo
https://github.com/Lameguy64/ps2serial

I think USB would be much more useful in the long run.

The Schematic in this repository will not work with every computer, you should use proper max232

gdjacobs wrote:

cyclone3d wrote:

Looks like the cheapest I can get a Teensy is $19.50 (+ shipping?) And that is for the v3.2 Or am I not seeing a much cheaper option?

I can get a Raspberry Pi Zero for $9.55 shipped.

In any case, somebody is going to be giving me an old Raspberry Pi to play with.

Don't get me wrong, Raspberry Pi boards are fun. It just seems wasteful to run a bunch of OS to emulate a serial mouse. 😒

Looks like Arduino Nanos are the most inexpensive option for AVR micro dev boards. It should be fairly straightforward to move from Matze' work to that, and the uC itself will run < 5 USD.

It also seems like even the current firmware for Matze's PS2 converter, which is in assembler btw, has issues with a lot of KVMs.

I'm not good with assembler, but I might be able to muddle my way through it, but the USB protocol is going to be a lot different then the PS/2 protocol.

Also not sure if 16Mhz is going to be fast enough to do the conversion without lag.

Here is another thought. Would it be possible to use a modified version of CuteMouse to support higher baud rates and thus better tracking with a converter? I'm guessing that it would be a pretty trivial driver change to do so.

Edit: Looked at the CuteMouse source. Looks like it only supports 1200 baud even with Logitech mice which support 2400 baud.

Would be a sweet change to have the converter run at say... 19,200 baud or higher for way better resolution with a USB mouse. For that matter, going even higher couldn't hurt anything could it?

cyclone3d wrote:

There is also code and schematics to make a PS/2 to serial adapter using an arduino board.
https://youtu.be/R_H84iGJeDo
https://github.com/Lameguy64/ps2serial

Thanks a lot for sharing that link! The schematic is interesting.. 😀
Is it really using a LM7805 as a level converter ? - I've never seen this before.
Weird, but interesting, still. Since the PC side is receiving data packets most of the time,
it could actually work without interruption.

Also, it looks like a good opportunity to test my self-made Arduino:

Edit: Seems there are also ATtiny versions of such a converter.
Tiny85 https://github.com/urjaman/ps2-to-rs232
Tiny2313 http://www.tempect.de/senil/ps2to232.html ,
https://hackaday.com/2017/10/09/a-converter-y … o-serial-mouse/

This is some awesome and promising work! I wish I had more talent for such things. It'd be nice to see someone do a limited run of these, pre-assembled and ready to go. I keep wanting to poke at Arduino, Raspberry Pi, etc. but I'm running out of workspace already and even more-so running out of free time. 😀

CODOR wrote:

I'd considered doing exactly this a year or so ago but realized I'd need to wire up the Pi's UART along with a GPIO pin to act a […]
Show full quote

cyclone3d wrote:

So while mulling over the fact that the only serial pointing devices I have are trackballs, I came across this program for Raspberry Pi that acts as an active converter to let you use a USB mouse on a serial port.

I'd considered doing exactly this a year or so ago but realized I'd need to wire up the Pi's UART along with a GPIO pin to act as RTS (used to reset the 'mouse') through an RS232 transceiver so nothing ever came of it.
Only now does it occur to me that I could have just used one of the USB<->RS232 adapters that I already have 😵

It's nice to see that someone already wrote the software, though; I've got a couple of original Pis gathering dust that would be appropriate for such a purpose. I suppose they could be considered overkill but they can always do other things at the same time like act as a file server using EtherDFS or something. Plus it amuses me that they could probably emulate most of the systems I'd want to attach a serial mouse to but I'd be using them for such a menial purpose instead 😀

Funny... somewhere around here I've got USB->PS/2 adapters... and PS/2 -> serial adapters. You'd think I'd be able just to string them together 🤣

Sorry to disappoint. Those USB to PS/2 adapters are more like PS/2 to PS/2 (there's a PS/2 chipset in older mice that switches on when hooked up to a PS/2 port).

Same with serial to PS/2 adaptors. They only work with old mice that support the serial protocol.

I would do the pi thing just to say that my mouse had more processing power than the PC it was connected to 🤣

.legaCy wrote:

Should work fine, but using a raspberry pi for this is kind of overkill, but hey, it is up to you.

There's a high probability that an RPi would cause enough of a delay to get annoying after a while.
Might be OK for a proof of concept, but by the time you've mucked around with the RPi you might as well have prototyped it on an Arduino.