Just finishing up with Basic Stamp Activity Kit.

khumfreville

So I'm just finishing up with the Basic Stamp Activity Kit, using the HomeWork board and the BS2, and I came up with an idea of a practical thing to make using it. I built my prototype using the HomeWork board, and now I'm getting ready to put the final draft together.

I have a few concerns though: because the design is so simple (just a sensor and an LED), I feel like using the BS2 for the job is a bit over-doing it. I'm only using the 2 of the 16 available I/O pins. Is there a better option for me than the BS2, which will be grossly put to waste in such a product?

Thanks in advance, for everything!

Martin_H

If you are concerned about cost you can use the BS2 OEM lite circuit (http://www.parallax.com/tabid/802/Default.aspx). Without knowing more details of the application it is hard to suggest anything else. But discreet components (comparator, logic gates, 555 timers) can do many things a microcontroller can do. For example, a 555 timer can pulse servos or emit 38 kHz IR.

khumfreville

The project is very simple. It is basically just a. Parallax distance sensor and an LED which turns on when the distance reports a minimum distance

Mike Green

It all depends on what you're really doing. If you're building a single concept demonstrator, then a Stamp is a perfect solution. It's easy to use, simple to program, and it does the job. If you're designing something to be manufactured, then you have to reconsider the whole thing. Remember that a PING (the distance sensor) is not cheap. It has its own microcontroller and LEDs plus other circuitry to provide the high voltage for the transmit transducer. I would spend the time to build up an ultrasonic distance from scratch based on ideas from some of the DIY designs (here's one) you can find on the Internet. The same microcontroller that handles the ultrasonic transmission and reception can easily do the additional decision making that you're doing with the Stamp.

Martin_H

OK, the Ping))) is best used from a microcontroller because you need to generate a pulse, time the response, and do some math. An AVR tiny or one of the PicAxe chips might be a possibility.

But here's an analog distance sensor:

http://www.parallax.com/Store/Sensors/ObjectDetection/tabid/176/CategoryID/51/List/0/SortField/0/Level/a/ProductID/776/Default.aspx

It outputs a voltage proportional to get distance. You could use that voltage coupled with a comparator IC to turn on the LED at the trigger point.

khumfreville

Thanks for all the great advice. I'm having a blast learning about the electronics stuff. My project is basically just something I can mount on my garage wall to tell me when to stop. Kind of like the hanging a tennis ball trick, but I wanted to be able to use these concepts to make it with the stuff I've learned.

Thanks again!