On Tue, Feb 7, 2012 at 2:44 PM, John Honniball <coredump at gifford.co.uk> wrote:
Philip Pemberton wrote:
And nobody seems to sell 3-button ball mice any more (well, not now
optical mice are down to the ?5ea price band), so you can't exactly buy
one of those, remove the PS/2 controller and add a 74LS14 to make a
quadrature mouse.
I found a data sheet for one of the early HP mouse chips that
said you can! ?The optical mouse sensor chip had quadtrature
outputs in addition to (I think) a PS/2 interface. I may have
been old enough that it required an additional chip to add
sipport for a scroll wheel. Anyway, I have a couple of mice
with that chip in, and one day I'll get around to making
a quadrature "tail" to connect to (say) the Atari ST.
Looking at some of the data sheets for current Avago Technologies
LED/Laser optical sensors it looks like the sensor output is serial
(SCLK/SDIO or SCLK/MISO/MOSI) and then there would be microcontroller
to connect that to PS/2 or USB or whatever.
http://www.avagotech.com/pages/en/navigation_interface_devices/avago_mouse_…
So with optical mice based on those sensors you would have to replace
the microcontroller with your own microcontroller to turn the serial
data from the sensor into quadrature output.