Any ideas?

Matt H.

Hey guys! I've been doing a robot with the BS2 for a couple years now and I'm wondering if it can handle a boebot cam? I'm thinking about using the robot as a facial recognition system or something along those lines. Thanks!

Matt

Mike Green

A Stamp has neither the memory nor the speed to do any kind of video processing. There is a version of the CMUcam designed for use with a BoeBot, but the Stamp does none of the video processing. It's all done by an SX microprocessor on the CMUcam and the Stamp just tells the SX what to do. Facial recognition takes something on the order of a PC for doing the processing. One of the little embedded Linux boxes like the Gumstix would probably have enough computing power.

Matt H.

Thanks, Mike. If you don't mind me asking another question, what about the ColorPAL? I'd be willing to work something out with that. I'm on a tight budget, sadly, but I think I could do some pretty cool stuff with something visual or related to color or light sensing. I already have a PING)) ultrasonic sensor and a Hitachi compass on the robot. It's original purpose was to travel in multiple directions (eg. Northeast then South) while avoiding objects, and then getting back on the same route after avoiding said objects. Any ideas for some affordable sensors that could work with the two that I have while doing a totally different task? I don't mind the code writing at all, but I'm out of ideas for the purpose of the robot.
Thank you so much, again!

Matt

Mike Green

You first have to think about the purpose of the robot, then figure out what you need to do it.

The ColorPAL is for contact color sensing. It needs to be very close to the object it's sensing. You could use it for a line following robot where you're using different color tapes on the floor for different branches on a path. The ColorPAL sensor would have to be mounted just above the floor for this to work.

You really want to use something like the CMUcam. Parallax's version of the CMUcam1 is $140. A plain CMUcam1 is $100 and would need some simple modifications and mounting hardware to hook up to a Stamp-based bot. This is not a cheap sensor, but sounds like it's closer to what you need for what you want to do.

Another inexpensive sensor to consider is the Linescan Imaging Sensor (www.parallax.com/Store/Sensors/ColorLight/tabid/175/CategoryID/50/List/0/Level/a/ProductID/566/Default.aspx?SortField=ProductName%2cProductName). This can be used with a Stamp and you could mount it on a servo to do a scan of an area. The main issue is again lack of storage and speed on the part of the Stamp to process the successive scans.

Remember that, by the time you get a Linescan Imaging Sensor and a servo, you're getting near to the cost of a CMUcam1.

Post Edited (Mike Green) : 1/3/2010 6:14:26 PM GMT

Electron Jeff

Am a newbie to the Parallax BS2. I am working with the servo programming and wondering what tells the stamp to go clockwise or counter clockwise? Any help would be appreciated.

Thank you,

Parkview

Post Edited (Parkview) : 1/3/2010 9:55:35 PM GMT

Mike Green

First of all, you need to download and read the "Robotics with the BoeBot" tutorial which explains a lot about servo motors and other simple robotics. Search for that name on Parallax's website (it's under "Downloads")

Servo motors respond to pulses that vary from roughly 1ms to 2ms in width. With regular servos, this pulse specifies the desired servo position with 1ms representing one end of the mechanical range and 2ms representing the other end of the range. With continuous motion servos, 1ms represents full speed in one direction and 2ms represents full speed in the other direction. 1.5ms represents a full stop.

Matt H.

Thank you, again! I will definitely take this to heart and work through some ideas. I'll post something on how successful it is come February when I hope to have it done.

Matt