Using DTMF to drive solenoids

Hi, You certainly need to consider the questions of John Fields but may I ask, why do you want to take the DTMF approach? You may find the decoding time is too slow for your application. There are many digital schemes that can do what you want. Tom

Dear All,

I am new to DTMF as well as to this group so forgive me in case of "stupid" questions...

I am looking for hardware to control 16 solenoids using DTMF tones. In fact I am building an instrument consisting of 16 automated castagnettes.

My goal is to find a solution as simple as possible to drive the castagnettes.

My basic idea is:

1) Use a MP3 player to store a "song" consisting out of differtent DTMF tones
2) Use a simple DTMF receiver connected to the MP3 player to detect the DTMF tones (e.g. MT8870D / MT8870D-1 Integrated DTMF receiver)
3) Use simple electronics connected to the DTMF receiver to drive 16 solenoids. (Solenoids: 12VAC or 12VDC)

Does anyone of you know a simple approach to do this? I know just enough about electronics to build a simple schematic.

I really hope anyone of you can give me some help!

Best regards, Eibert Draisma.

--- It sounds fine to me, and here's how I'd do it:

+V | +----------+ |K | [1N4001] [SOLENOID 16] | | +----------+ Vcc | | +--------+ C +---------+ +---|LE Q15|--[R16]--B Q16 DTMF>---|Vin Q4|---------|A3 Q14| . E | Q3|---------|A2 Q13| . | | Q2|---------|A1 Q12| . GND | Q1|---------|A0 Q11| . | | |\\ |_ Q10| . | StD|--| >O--O|E Q09| . +V +---------+ |/ | Q08| . | MT8870 | Q07| . +----------+ | Q06| . |K | | Q05| . [1N4001] [SOLENOID1] | Q04| . | | | Q03| . +----------+ | Q02| . | | Q01| . C | Q0|--[R1]---B Q1 +--------+ E HC4514 | GND

If you know what solenoids you want to use (or their actuation current) I can recomment suitable MOSFET or bipolar driver transistors and base resistors. Also, if you don't need more than the one inverter on the ENABLE input of the 4514, it would be easy to sustitute a transistor and save a chip.

-- John Fields Professional Circuit Designer

Castagnettes being two small wooden paddle things tied together with a piece of string? - Like the flamenco dancers use?

You want to automate 16 small wooden percussion instruments?

....hmm...this isn't going to sound good, is it?

Dear John,

My idea was to drive one solenoid at a time; I can imagine driving more solenoids (each related to a specific DTMF tone) simultaneously would result in problems concerning the decoding? The solenoids should only be "on" when their DTMF tone pairs are hot; I simply would record a "DTMF-tones song" and store it on a MP3 player.

What do you think; would this work?

Eibert Draisma.

"John Fields" schreef in bericht news: snipped-for-privacy@4ax.com...

DTMF

I don't care about the delays as this concerns a stand alone instrument; performing only now and than when it feels like performing...

The only reason I wanted to use DTMF is I think the electronics can be cheap. (I don't need all kind of advanced midi possibilities) Besides this I would like to keep the circuitry as simple and compact as possible.

Do you think this is the right approach?

Eibert Draisma.

No, this is not going to work. The delay's for DTMF are to big to do ritmitical things like castagnettes. The delay's should not be bigger than 10 mSec.

What you should do is tell us what you want to do, then people can give sugestions instead of you giving solution while we don't understand the real problem.

Good luck,

Peter NB. (and you shouldn't crosspost to 6 groups comp.robotics.misc should be enough).

--Sill me; what is DTMF? --I'm using solenoids as well, via Stamp, but to control a (fairly primitive) tap-dancing robot.

-- "Steamboat Ed" Haas : Just another fart in Hacking the Trailing Edge! : the Elevator of Life...

---Decks a-wash in a sea of words---