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Topic: Recommendation on a 13+ inputs digital multiplexer. (Read 919 times) previous topic - next topic

Thot

Thanks again for the replies.

Crossroads: The "Wireless route " was going to be my next step (if I can make the whole thing work with wires, that is). I was thinking bluetooth but I don't know if there is a module for this and even if there is, what would be the simplest solution, Bluetooth or RF?

fungus: I was not aware of that, thanks for pointing it out.

There are three kind of people in the world: Those who can count, and those who can't

DuaneB

Have you considered Repurposing an existing keyboard ? The keys are generally connected in a grid so rather than having to read 100 keys you can just read the columns, the key is then to switch the rows on one by one, each key connects a unique combination of row and column if you know which row is switched on, its easy to know which keys are pressed.

This is my example but there are many other similar approaches, you can even combine this with shift in to get the required pin count down to 5 -

http://rcarduino.blogspot.com/2012/10/five-dollar-synthesiser.html

Duane B

fungus


I was thinking bluetooth but I don't know if there is a module for this and even if there is, what would be the simplest solution, Bluetooth or RF?


It depends on the distance and what you want to connect to.
No, I don't answer questions sent in private messages (but I do accept thank-you notes...)

CrossRoads

RF is certainly less expensive - RX/Tx pairs for <$10, or nrfl2401+ transceivers for $5-6 each.
Wiring up 13 keyboard switches to a promini and 1 wire for a TX module won't take long, and then a simple loop to read the keys and create 2 bytes for virtual wire to send out.

Designing & building electrical circuits for over 25 years. Check out the ATMega1284P based Bobuino and other '328P & '1284P creations & offerings at  www.crossroadsfencing.com/BobuinoRev17.
Arduino for Teens available at Amazon.com.

Thot


Have you considered Repurposing an existing keyboard ?
http://rcarduino.blogspot.com/2012/10/five-dollar-synthesiser.html

Duane B



Hello DuaneB.
I was aware of your $5 Keyboard, it came up during my researches. It's amazing but it sounds a bit complicated. My project is simpler and I wanted to see if I can do it from the ground up.
fungus: The distance is not much (same room say) but cost is important (and when isn't? :)).
I think I'll just go with 1 wire per push switch (plus common ground) for the time being and later explore Crossroads' RF option for true portability (I'll have to do some more research on that, any good tutorial out there?).


Thanks again

There are three kind of people in the world: Those who can count, and those who can't

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