CMUcam to StampSX

Archiver

I've been working on a robot for some time now and am using a
CMUcam to detect a tennis ball. So far so good, but I've run into a
problem with communications with the CMUcam. It seems to work fine
initially, but after I start the unit it runs nicely for a short
while and then the camera fails to respond and the unit runs amok
(because the Stamp is hung up and the last command it send to the
motors keeps running.) Anyone have any insights? I was wondering if
the outputs from the SX28 might need a pullup resistor. I've read that
there are internal resistors for Inputs, but since I'm having issues
with output, I wondered if outputs are floating on the SX28 as part of
the design.
Anyone have any insights that might be useful?

Thanks


Cat

Archiver

Hi Cat

Several possibilities come to mind -

1) Low batteries can cause erratic behavior of the CMUcam and Stamp - the
CMUcam sucks battery power in a major way - use an AC adaptor for initial
testing - something like a 6 volt 1 amp unit.

2) If you are using a high baud rate switch to 9600 baud temporarily for
testing and see if the problem goes away. The Stamp is an odd bird when it
comes to instruction execution time. Things like SERIN can take longer to
execute if they are run after a PULSOUT command.

Thank you
Ron A. Nucci
Seattle Robotics

Archiver

Great call Ron!

Yep the CMUcam is sucking my power supply to a minumum working
voltage and any operations cause it to hang.
You Seattle Robotics folks are good to the point of being scary!
Many thanks for the advice


CAT



--- In basicstamps@yahoogroups.com, "Ron A. Nucci" <r.nucci@w...> wrote:
> Hi Cat
>
> Several possibilities come to mind -
>
> 1) Low batteries can cause erratic behavior of the CMUcam and Stamp
- the
> CMUcam sucks battery power in a major way - use an AC adaptor for
initial
> testing - something like a 6 volt 1 amp unit.
>
> 2) If you are using a high baud rate switch to 9600 baud temporarily for
> testing and see if the problem goes away. The Stamp is an odd bird
when it
> comes to instruction execution time. Things like SERIN can take
longer to
> execute if they are run after a PULSOUT command.
>
> Thank you
> Ron A. Nucci
> Seattle Robotics