Sharing Memory Between Processors? 2

[eromlignod]

Hi guys:

I'm an ME and I have an application where I'd like to use two Basic Stamp microcontrollers working together. One is the main processor that runs the show and does calculations; the other is a dedicated slave that constantly distributes a series of 16-bit numbers to
various devices in a continuous, timed loop. The first processor calculates what these numbers are based on feedback sources.

The reason I use a dedicated second processor is that its stream of numbers can't be interrupted...it has to provide a continuous series of values on a clock. The problem is that I can't even interrupt it long enough to pass numbers to it from the other processor without messing up the sequence.

What I'd like to try (if possible) is to share the same memory between the two MCU's. So the first Basic Stamp is calculating values and storing them to memory and the second Basic Stamp is using them as if they were in its own memory bank simply by referring to a value by variable name (or address??...I don't know).

Is this possible and, if so, what would be a good way of going about it? I'm also open to alternate suggestions to solve the problem including using a different processor (I would like to avoid investing in another development kit or chip burner if possible though).

Thanks for any help you can provide.

Don

 

[VEBill]

Does one exciter/pick-up coil cover all 2 or 3 strings in one set of strings (for one key)? You'd mentioned having only 88 coils but 256 heater circuits. Do you use FFT to ferret out each of the three strings at once? Or use the different frequecies to sort them out?

Two cycles per second for the heating control loop should be dead easy, even with the required very fine (1 or 10 uS ? *) resolution of the exact duty cycle. You should not run into any problems with lack of processing speed.

* Have you confirmed the exact resolution requirement for the duty cycle value? You need to confirm if 1/256 (or 1/1k or 1/1M) is fine enough control of the duty cycle. 1/256 seems a bit course. If you're a shade too high or low, then the string will slowly drift unless you close the loop (recommended).

With suitable SW, you could interpolate the duty cycle in between what the hardware is capable of (keeping in mind the thermal time constant). I'd just make it as fine as possible and close the loop.

I'd add a USB port too for uploading and downloading settings and saving personalized tuning scales.

With respect to Patents and IP, it seems to be not uncommon practice to have a flow of refinement patents going through the office (slowly) so that you effectively drag out your monopoly decade after decade after decade.

 

[MacGyverS2000]

...and the patent office has been getting wise to such schemes and is cracking down on it. Judges are starting to toss cases and patents because the "refinements" were obviously meant to do exactly what you describe.

Dan - Owner

http://www.Hi-TecDesigns.com

 

[nbucska]

Don:
Do you update the tuning while the piano is being played,
too? What do you do about the coupling betveen the keys?

Knowing so much more, I would use a custom designed processor board with a 186 - the question is how to interface it to the sensor coils and the power switches.

The circuits are simple but to reduce the production cost
it may be worth to develop special custom IC-s.

Wouldn't be cheaper to use one tuning unit which would
slide across the strings, measure each in turn and
tune it mechanically ?




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