Would this work in theory? Basic keyboard using analog input

Using Arduino Project Guidance
#1

I am still new to the Arduino, very tired but I want to make a very simple alarm just for fun with stuff I already have in. I thought I would make a very basic keyboard but rather than use an input pin for each key I thought I could do it with the analogue pins by varying the resistance and this the voltage the pin receives according to the switch that was pressed?

Would this work in theory?

IGNORE THE CAPACITOR VALUES, I have not worked out what sizes I need yet, on the board each capacitor will be a different value to vary the voltage

Thanks.

#2

Sorry I forgot to upload the breadboard diagram.

keyboard_bb.jpg
keyboard_bb.jpg1809×1284 316 KB

#3

All the voltages will be the same - if you want different voltages, use voltage dividers
(There aren't any capacitors to ignore)

#4

That was what I was getting when I put my multimeter on it, (without connecting anything to the Arduino but running on seperate PSU).

Why would the voltage be the same even if the resistors are different values? I think my basic high school and old knowledge of electronics is failing me!

#5

I'm posting from a phone, so no drawing, but imagine a 1Mohm resistor with one end connected to 5 V.
What is the voltage between the other end (which is unconnected) and ground?

Now connect another identical resistor in series.
What's the voltage now?

#6

It the same voltage no matter how many resistors I put in series.

#7

Correct.

#8

So I need to connect another resistor from the analogue pin to ground?

#9

Also correct.

#10

Thanks, I will read up on the calculations tomorrow, I need sleep now :).

#11