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Topic: 255 Analog Ins (Read 1 time) previous topic - next topic

greeneD

Hello,
Yes, you heard right, I need 255 Analog Ins with a rez of 8bit for each In.
That's a data rate of ~8MB/s that I need to process ASAP (less than 1/60s).
I couldn't find a board that's able to keep up with that data rate.

And it has to be "cheap" (less than 200€ for board and multiplexers)

Thanks a lot for your help.

Maris.

westfw

How do you get 8Mbps?
255*8*60 is about 125kbps...

(I still don't know of anything that can do that.  Just managing the "fanout" of the digital signals involved sounds awful.  Much less at the price - you're talking about < $1 per analog input!)

greeneD

Hmm... I thought about using multiplexers but I don't think I can read at the rate required for the MIDI protocol. I want to build a 150mm x 750mm pressure-sensitive matrix, kinda like a seaboard rise.
sadly tho, I can't afford a 1400€ 88key MIDI controller.
If you can help me get it total under 500€ it would be gladly appreciated.

-Maris

lcvieira_br

Just a suggestion: would it work in a mixed way, I mean, 32 groups of 8 keys? You'd use 32 A/D converters with 8 keys each, 3-bit scanner at a continuous rate. Chances are it would suffice both your budget and technical requirements.

Cheers.

westfw


Quote
a 150mm x 750mm pressure-sensitive matrix, kinda like a seaboard rise.
How about some hierarchical setup where you use, say, a touch controller  to figure out which group of sensors actually need to be read?  You're unlikely to have all 88 keys + extras activated at one time...



greeneD

hmm.. that might work, but its still 30keys to read at any given time (10 for each finger + buffer zone)
that's still a lot.

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