HariFun #143 - How to read a 4x4 keypad using just one Arduino pin!

Показать описание

Рекомендации по теме

Комментарии

Best approach is ALWAYS through practical example. Thx!

nosuchthing

I made myself a 3x3 keypad and it is working really fine just like professional 4x4 or

4x3 keypad! Thanks Hari Winguna!!!!

raagamparmar

I was scratching my head just now. took me two days wrestling around this keypad problem until i saw your tutorial.

salesrlcshoppe

Thats the smartest thing i've seen today! Big thanks and Hats down to you sir.

shinevisionsv

After days messing about trying to get this to work I had all but given up. The problem was the voltage out numbers I was getting were nothing like the progression you were demonstrating in your video, they were all over the place. On top of that they kept fluctuating over time so I couldn't program the threshold values with any certainty.

Then I had a spare keypad delivered so I thought I would try that as a last resort - SORTED!! The voltage numbers were spot-on and gave consistant results. Anyone else having trouble with this should try different keypads to see what results they get. The first keypad was brand new as well by the way.

Thanks for a very useful video Hari.

ashleyhouse

How is it possible to read out 16 keys WITH JUST ONE PIN? Concentrated MAGIC! Wow, thank you! THAT's how it needs to be done. :)

hstrinzel

Cool. It's a very old technique that was (and probably still is) widely used with small passive controllers for professional appliances such as the Alesis LRC which was a tiny controller for the Alesis Adat digital recorders; it has 13 buttons and terminates on a TS jack; I made a PIC18 project to read this controller and use it as a generic MIDI controller; the downside is that you have to apply a debouncing algorithm with a rather long debounce time in order to get a stable voltage before trying to recognize which button was depressed.

GenuineSoundware

The solution using an i2c is hand waving magic that I don't really understand. I like to understand what my circuits are doing and I do know Ohm and Kirchhoff so this is fully comprehensible - thank you for this ingenious solution.

tensor

You are a Genius ! Can you share a schematic with all resistors on the matrix ?
Do you think that this method can work for a 900 switchs ?

SamBatti

awesome video! the way you explained the keypad wow! inspired me to 3dprint a keypad of my own.

ranieldenicen.marpuri

I can't use the adjective that I want to use, so I will just say "Really" brilliant man! Nicely done and thanks for this!

jcduplessis

Thank you, this is so complicated, if you don't know how, but as soon as someone pushes your nose on that or you realise it yourself, it is so amazingly simple and logic, I mean the analog pin reads voltage, so what is more logic than adress each button with a different voltage? And as soo you got it, you just think "why I didn't had the idea myself or why didn't it came earlier to me, grrrr, D'oh?", I'm using this already simply with the oneWireKeypad.h library, because it makes it all very simple and most important it isn't using any delays, but still interesting to watch, the way you explain it, the exited voice shows me that you are still amazed about how simple it actually is.

WilsonKS