USB in python

[Muriel de Souza Godoi]

Some people got success in Arduindo using an older mobile cable which works
as USB/Serial converters.
So you can read and write data as a serial port using pyserial.

On Tue, Jan 27, 2009 at 8:31 AM, Lie Ryan <lie.1296 at gmail.com> wrote:

> On Mon, 26 Jan 2009 11:08:48 -0600, Unknown wrote:
>
> > On 2009-01-26, Lie Ryan <lie.1296 at gmail.com> wrote:
> >
> >> How about (a crazy idea) using the audio jack out? (DISCLAIMER: Little
> >> Hardware Experience). High pitched sound (or anything in sound-ology
> >> that means high voltage) means the device is on and low pitched sound
> >> off.
> >
> >  1) Pitch has nothing to do with voltage.  A high-pitch sound
> >     and a low pitch sound can have the exact same voltage.
> >
> >  2) The OP's device requires quite a bit of power.  There is
> >     almost no power available from the line-out jack, and the voltage is
> >     limited to about 1V.  If his sound card has a power-amp (none do
> >     these days), he might be able to get a usable amount of power.
> >
> >> The device will need an additional transistor to separate low voltage
> >> from the high voltage.
> >
> > He'll need more than a transistor.  He needs a power supply, some sort
> > of rectifier/detector, and a comparitor. It would be more interesting to
> > use notch filters to detect different frequencies so that you could have
> > multiple output "bits".
>
> >From the little I know on electronics, a simple, single transistor would
> (almost) immediately switch from on-to-off-to-on depending on the voltage
> of the control pin (I think it was the middle pin). I was suggesting this
> simplistic hack because as far as I comprehend the OP's need, he only
> need on-off switch instead of a complex multiple output bits.
>
> >> I don't know how much power can be pulled from jack out,
> >
> > Almost none, and what's there is very low voltage.
>
> That's why the power is taken from USB port.
>
> >> but for a home brewn device it is still feasible to draw power from USB
> >> and signal from jack out.
> >
> > It would probably be easier to buy a USB-parallel port chip. Then he's
> > got power from the USB bus and something like 14 parallel I/O pins he
> > can control.  Alternatively A USB-serial chip will provide 2 outputs and
> > 4 inputs.
>
> The idea was made on the basis that a USB microcontroller is not used.
> Getting power from USB should be much easier than getting data while the
> jack out can provide simple on-off signal.
>
> --
> http://mail.python.org/mailman/listinfo/python-list
>



-- 
Msc. Muriel de Souza Godoi
Computation Department
State University of Maringá
Brazil
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