Linux robots (mouse cables have lead?)

[markw at mohawksoft.com (markw at mohawksoft.com)]

I went to Microcenter Today, I could not find a single serial mouse.
Plenty of PS/2 mice, plenty of USB mice. Not a single serial port mouse.

I figured I could use a USB mouse for the system mouse and use the PS/2
port to run the encoder stuff. I'm going to take apart the mouse and use
the LED and dual detectors right at my encoders and use the CTC/serial
mouse works to do the rest. I'll split the X/Y mouse channels to
differential drive channels on the robot.

The mouse I bought was a Memorex Raton PS/2 3 button mouse. really cheap.
Well, on the end that plugs into the computer, there is a tag that reads:

Warning:
Handling the cord on this product will expose you to lead, a chemical known
to the state of California to cause [cancer, and] birth defects or other
reproductive harm.
Wash hands after handling.


Scary.


>
> markw at mohawksoft.com wrote:
>>>Yes.  Rip open a $5 serial mouse and use its encoder.  I've seen this
>>>outlined in an old Circuit Cellar article, though I doubt I still have
>>> it.
>>>You should get pulses at the mouse's 300DPI.  You might even be able to
>>>just mount the mouse pushing up against your wheel without
>>> modifications.
>>
>> Hmm, that has some interesting prospects I hadn't considered. The one
>> problem I have is that I need two: I have a diametrically opposed wheel
>> setup.
>
> OK, $10  ;)
>
>
>> I very much like the idea of an interrupt driven and kernel buffered
>> system that I don't have to write or debug. If I rip apart the mouse, I
>> could use an axis for each wheel and the buttons for contact sensors. I
>> could use select to wait on the serial port. Since the encoders are read
>> at the same time, maybe the relational movement will also be more
>> accurate.
>>
>> I need to think about this, it is a very good concept. Very good inded.
>> Thanks.
>
> OK, here's another one, making even less work for you:  gpm has a -D debug
> option that will spew mouse events out to stderr.  Call that and read its
> output and you don't even have to write the serial mouse interface code.
> And, depending on what mechanism you use, the events will be buffered so
> you
> don't miss any.
>