cmucam1

Archiver

Hi,

I'm trying to use CMUcam with BS2p40 for a line tracking mobile
robot. Any answer, recommendation, sample application, code etc. is
very wellcomed.

1) To understand what the camera sees, I connected it directly to my
PC at 9600 baud rate. CMUcamGUI Java program gives a shrinked version
of the image. I tried to play around the java code but couldnt get
anything better.

2) Straight line tracking seems to be easy but I still struggling to
figure out how to distinguish crossings. Only having left, right and
middle mass coordinates seems far from being enough to develop a
robust controller.

3) The voltage regulator 7805 gets too hot. I think 200 mA of current
shouldnt heat it up that much. I checked input (12VDC) and output
(5.00VDC) voltages and everything seemed to be working fine. But, the
heatsink becomes so hot that it is impossible to touch. I have
changed almost every component but no luck so far.

4) I actually bought two cameras but one of them didnt work at all
(except its power led) and I have sent it back to the company I
bought it from. At my first experiments, the other one was freezing
after working for a couple of frames. This isnt happening lately but
I dont know neither why it was freezing nor what corrected it.

Thanks very muc for any response

Murat

Archiver

200 mA at 7 volts (12 - 5 == 7) is
1.4 WATTS. It could use either a bigger
heat-sink, or some heat transfer grease,
or a heat-transfer insulator. I think
with a heat sink it can dissapate 5 watts
before anything bad happens. And the
bad thing that happens is thermal-shutdown,
so it protects itself, and there isn't any
damage. Still, could be a current drain
somewhere...

I'm not surprised it gets warm. Some
people use a 7.5 volt power supply for
these purposes (7.5 - 5 == 2.5 volts,
* 200 mA is .5 watts. Much easier to
dissapate.)

As I understand it, the CMUCam has a
line-tracking mode -- it was built for
this purpose at Carnegie-Mellon University,
where it won an undergraduate competition
for Robot navigation.

Don't know if this helps you at all, though.

--- In basicstamps@yahoogroups.com, "m_a_y_y_i_l_d_i_z"
<mayyildiz@m...> wrote:
> Hi,
>
> I'm trying to use CMUcam with BS2p40 for a line tracking mobile
> robot. Any answer, recommendation, sample application, code etc. is
> very wellcomed.
>
> 1) To understand what the camera sees, I connected it directly to
my
> PC at 9600 baud rate. CMUcamGUI Java program gives a shrinked
version
> of the image. I tried to play around the java code but couldnt get
> anything better.
>
> 2) Straight line tracking seems to be easy but I still struggling
to
> figure out how to distinguish crossings. Only having left, right
and
> middle mass coordinates seems far from being enough to develop a
> robust controller.
>
> 3) The voltage regulator 7805 gets too hot. I think 200 mA of
current
> shouldnt heat it up that much. I checked input (12VDC) and output
> (5.00VDC) voltages and everything seemed to be working fine. But,
the
> heatsink becomes so hot that it is impossible to touch. I have
> changed almost every component but no luck so far.
>
> 4) I actually bought two cameras but one of them didnt work at all
> (except its power led) and I have sent it back to the company I
> bought it from. At my first experiments, the other one was freezing
> after working for a couple of frames. This isnt happening lately
but
> I dont know neither why it was freezing nor what corrected it.
>
> Thanks very muc for any response
>
> Murat

Archiver

I've been using a BSIISX with the CMUcam. The regulator does heat up
but this is normal. Mine gets too hot to touch but doesn't shutdown
and in my experience, it's not unusual for a regulator to dissapate a
lot of heat.
I did experience some odd freezes and asked for advice in this
discussion group. A member of Seattle Robotics suggested I check that
the unit was not draining the battery power supply I was using. I
found out it was indeed draining the battery much faster than I
thought it would and the lower voltage was causing halts. (Those
Seattle Robotics people are good!)
Not sure about the line program... I suggest you try the Seattle
robotics site or the CMU site on the CMUcam. There may be some
discussion there.
One last thing. In my indoor application, it dramatically improved
the preformace when I added an IR filter to the CMUcam.
Hope this helps


CAT



--- In basicstamps@yahoogroups.com, "m_a_y_y_i_l_d_i_z"
<mayyildiz@m...> wrote:
> Hi,
>
> I'm trying to use CMUcam with BS2p40 for a line tracking mobile
> robot. Any answer, recommendation, sample application, code etc. is
> very wellcomed.
>
> 1) To understand what the camera sees, I connected it directly to my
> PC at 9600 baud rate. CMUcamGUI Java program gives a shrinked version
> of the image. I tried to play around the java code but couldnt get
> anything better.
>
> 2) Straight line tracking seems to be easy but I still struggling to
> figure out how to distinguish crossings. Only having left, right and
> middle mass coordinates seems far from being enough to develop a
> robust controller.
>
> 3) The voltage regulator 7805 gets too hot. I think 200 mA of current
> shouldnt heat it up that much. I checked input (12VDC) and output
> (5.00VDC) voltages and everything seemed to be working fine. But, the
> heatsink becomes so hot that it is impossible to touch. I have
> changed almost every component but no luck so far.
>
> 4) I actually bought two cameras but one of them didnt work at all
> (except its power led) and I have sent it back to the company I
> bought it from. At my first experiments, the other one was freezing
> after working for a couple of frames. This isnt happening lately but
> I dont know neither why it was freezing nor what corrected it.
>
> Thanks very muc for any response
>
> Murat