KeyPad 1 wire

Other Hardware Sensors
1

Good morning to everyone,
I tried to connect a keypad 4x3 at arduino through 1 single pin. I found the details at page: Arduino Playground - OneWireKeypad Library

I realize the connections and all the code with the sample in the library attached. Problem is that key are not working. I'm using resistors and pin as per the image.

Is there anyone else tried it?

Anyone can help me? If you need any additional detials, please let me know

Best regards

2

First, test the wiring. You will need a multimeter to verify the connections, and that different voltages appear on the keypad output lead, when you press the buttons.

If that all works, it may be a software problem. Read and follow the instructions in the "How to use the forum" post for how to proceed.

3

Thanks for you advice. Where can I found the correct voltage? Problem at the end is that I don't have any value to campare with. As of now I can see that software is reading a value but it is always the wrong one.

I tried in the library but I was not able to get. Can you please help me?

Which portion of the how too I need to read?

4

The important point is that the keypad output must present a voltage value that is unique for each key on the keypad.

The exact voltage value does not matter, as long as your program can read that voltage and use it to determine which key was pressed.

5

Not really a one wire keypad. Takes 3 wires. 5V, ground and the output to an analog input.

6

My biggest problem is that value are not stable. I tried also to couple a condensator to stabilize the values, but I was not able to solve. I would need mostly to stabilize the A0 read. because it change also sometime of 10/15%. Any Idea?

thanks

7

I tried also to couple a condensator to stabilize the values,

Where did you put the capacitors? A 0.1uF cap from ground to A0 might help.

8

Hi, thanks for the answer. This was also my understanding. I'm trying to attach some pictures but I can't. By the way yellow is connected to A0 and black is GND and condensator is connecting both of the wires. Please let me know if you see anything wrong. Also after adding the capacitor I could not see any advantage. Strange is that I took code, esample and schema from arduino site Arduino Playground - OneWireKeypad Library

Can you please suggest? Please let me know if you need more details