Interfacing tatio active high spinner using a Pi Pico

[bonesai26]

Hi

I've been making control panels using Pi Pico as they are dirt cheep and programming through Circuit Python is easy.

I've had an original Tatio spinner lying around for years, and I've never got it to work - as I've discovered reading here, its an active high device and therefore I can't use it with the U-Hid that cam with my trackball, nor the trackball pins on my iPac2.

My thoughts have turned to the Pi Pico - and can I use it to interface the spinner without buying an Opti-pac? My gut says yes, but my head isn't there yet

[baritonomarchetto]

You can, sure. Just remember to place a pulldown resistor (i.e. 10K ohm) to each data line (a total of two then).
The 3.3V logic should be not a problem as long as you drive the spinner @3V. Eventually a voltage divider (or other stepdown technique) will do the trick. If you don't want to mess with 3.3V logic, Arduino pro micro or Leonardo is the way

[bonesai26]

Thanks - will give it a go and report back.

[RandyT]

The 3.3V logic should be not a problem as long as you drive the spinner @3V.

Not so sure that would be possible.  Opto-sensors use IR LEDs, which have resistors in-line to regulate the current (voltage) to that which allow them to work.  At minimum, it's very likely that a spinner would need to have some board level modifications to work decently at 3.3v, or even work at all.

[baritonomarchetto]

Sure, what you said is correct, but using 3.3V at the spinner is worth a try

[RandyT]

Sure, what you said is correct, but using 3.3V at the spinner is worth a try

Probably not.  The typical IR LED operates at 1.7v (with many operating below this value).  The voltage differential between 5v and 3.3v (1.7v), with the resistor intended for 5v operation, is the same as the forward voltage of the LED, essentially nullifying everything which would allow it to function if given only 3.3v.