Which Micro for this project?

Gary10

I would appreciate some help in picking the appropriate Parallax product. My application consists of keeping track of a screw jack's position by counting the teeth on the input shaft gear. The shaft rotates at 450 rpm and the gear has 20 teeth. This means I will have a pulse rate of 150 per sec. As the shaft rotates 244 revolutions for full jack travel I will accumulate 4,880 counts during one jack cycle from down to up.

I need to be able to start the motor in forward or reverse, control the motor speed via a 0-10v signal, detect for a jam and provide a soft start and finish via the variable motor speed and I'm sure there will be other requirements the arise. The motor control signals will go to a variable frequency drive. I plan on a one button control similar to what would be found on most garage door openers.

If someone could tell me which BASIC micro would be appropriate for this application I would be most appreciative. If I haven't provided the necessary input to make a decision, please let me know.

Franklin

I would think with the specs you have provided so far you should look at the sx chips or the propeller.

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- Stephen

bulkhead

Sounds like all you need are:
1) Pulse counting ability up to 150 hertz; you may be able to use a simple phototransistor/LED combo to generate the pulses
2) Vary an output voltage from 0-5V; to my knowledge most stamp's outputs only go up to +5V, you'll need some other circuit to go up to 10V
-ability to program a soft start and variable speeds is pretty much possible on any microcontroller, otherwise it wouldn't be a microcontroller

Seems to me that any stamp (even BS1?) could do this, just counting pulses up to 150 hertz and outputing a varied voltage (through PWM or otherwise).

Gary10

Thanks to both Stephen & Bulkhead. I will give an sx a try.

Gary