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Sometimes, looking around the electronics trash at my local electronics dealer could feel like a walk in the candy store (where candy is free). Todays find is the Logitech M-M28 serial computer mouse, and boy was I happy when I got back home to google this thing. They go for over $50 on some webshops!
So little information, only logitech them self is the only source of info, though they only provide the line “First Mouse™ M-M28 SerialM” Where SerialM is the “DeviceModel =string” (?). This is the detection string the driver uses to draw the correct picture of the device in the Mouse Properties. This information is stored in the Windows Registry.
But where is the driver? Doesn’t really matter, does it? As you have already thought, I will not replace my USB optical mouse with this, I wan’t to use this in a project somehow. I’d appreciate a comment if you have a good idea of implementing this thing in some way.
The thing is in mint condition, glad I found it before the snow came falling down.
I connected it to the stationary computer at my home laboratory, and sure enough it outputs some specific bytes on each 1/20 turn or so on the rotary encoders and on mouse clicks. But when I got to my apartment using my Win 7 laptop with a USB-serial converter and Putty instead of HyperTerminal I don’t get any output. Hopefully I can capture some screenshots at one of the stationary computers at school tomorrow.
Here is a look inside
I have not found any information on the chip manufactured by Motorola(?) for Logitech. In case you don’t want to read it all from the picture, here is what is says
Pretty simple construction, with the chip doing all the work on both decoding the rotary encoders and RS232 signal transmitting.