Analog keyboard-7buttons for only an analog input

Hi all I have designed the layout of an analog keyboard using a pre-drilled PCB and a handful of push buttons and resistors. It is mesh up of some ideas taken from the web (resistive network, lcd driving, etc); I consider its clean and easy layout very useful. It uses only one analog input ed is designed for 7 buttons. You could find the complete article with the sample code at:

there you could find details and the sample code.

I hope it could be useful bye alex

Nice little write up. I'm gonna have to try that one.

Good work.

Hmm - this does seem useful, and it is very well laid out. Something I noticed in the article under "How to":

2.solder resistor: don't cut rheophores, but use them to create the circuit;

"rheophores"? I assume something got lost in translation; I think you meant "the leads", as in "2.solder resistor: don't cut the leads, but use them to create the circuit;".

Other than than that minor bug (as well as maybe a "warning" letting users know not to press more than one button at a time, which could lead to unknown values), I think it is a pretty good writeup, and something that I could see being manufactured for Arduino and general uC usage (such as by Phidgets - maybe you should contact them?).


I toyed with the idea of doing this. I even went so far as to work up an Excel spreadsheet to calculate values and voltages so you could choose what size resistors you wanted. It's still a manual process, but you can see the expected voltages when you push a certain button. I was trying to maintain a fairly equal separation in voltage between each of them. If you'd like the spreadsheet, PM me and I'll e-mail it to you.

for cr0sh: Please read, where you could find the right term to use to give the proper noun to the connectors of passive and active components. IMO I think that it is not a bug .....only an unusual but correct term (I used the master in traslation - Google)!!!

for flyboy: Sorry but my english translation is extremely concise. I missed the part about the simulator in java, where you could compute the value for resistors. Look at the italian page: There you could find the url and the source of the resistor network. It's a beautiful applet that allows to design a circuit and to test it posing scope-points to watch the voltage and the current levels. You could interact changing potentiometers value, voltages, frequences of AC generators and closing and openeing switches. bye alex

Hmm - learn something new everyday; I didn't even know that was an actual word! Maybe I should work it into my technical vocabulary?

I am a pretty voracious reader (I personally own a 5000+ book library in my home), and I have never seen that term used before (honestly, not even in any of the electronics and mechanical books I have from the beginning of the 20th century).

It sounds antiquated, though; like some out-of-use term from the late 1800's or early 1900's. I suppose if I were into steampunk...

While it may be correct and proper english, I would definitely consider your audience and change it to "leads" or "legs"; it would help prevent confusion.


Also, interestingly, this definition:

Mentions that it was published in "Webster's Revised Unabridged Dictionary, published 1913 by C. & G. Merriam Co.", confirming my suspicions as to the word's age and such.

That doesn't mean it is out of use; I managed to find a patent that referenced the word, and a few other online dictionary entries of a much more recent vintage, but it still seems like a word that would cause more confusion than anything for modern readers - especially since, given its definition, the words "leg"/"lead"/"wire" suffice perfectly and everyone involved with current electronic design knows what they mean.

Sorry for the trigging of this flame!

I'll use the term you suggest the next time, to avoid these annoying debate: I thinked about this forum as a technical board not as the meeting of english-american language purists...

I agree with you that Rheophore could seem unusual and a bit antiquated, since I am not a master of language: I'm italian and it is very hard and difficult to be clear with a foreign language.

But I accept you suggestion and I'll change the term according to the needs of the audence, altough it seems that this threed is going OT.

I hope to receive techincal hints for the future and that people would apprecciate my exhibitions, instead of arguing about the language.

bye alex

There's also the Wiktionary version too.

Yes crOsh is a time waster/diverter. You find many on this site unfortunately

I have found the term commonly used along with rheostat

They refered more yo the big solid wire wound jobs and are still used in heavy industry

[u]Well done accorias [/u]

Oh, hi, April - I've heard about you; glad to see you back! Obviously, you haven't landed in a burn ward yet! I hope your project continues to work out, ok? Seriously - I only want the best for people; you included! ;)

acorrias, there is no flame or animosity going on; I understand that english is not your primary language - indeed, I know not a lick of italian, so you have that on me! :)

My only concern was that since you wrote the post in english for (presumably) english language speakers, you would want to use terminology that is most likely used by electronics enthusiasts. As I noted before, I have never seen anyone else use that term - and it was nice to learn a new word as well.

I think your board is well designed; it really shows what can be done with a simple bit of PCB, some minor-cost parts, and very careful layout - really, it is an example that could be used as a circuit layout and design example for an EE course.

Thanks for sharing it!