Can't get switch closed signal due to length of wire - anyway to compensate?

[drock1985]

Hi,

I'm re-wiring my current doorbell/chime system and instead of the wiring running low voltage AC, I am going to use them as digital switches. I installed everything, but the doorbell does nothing. I then installed my breadboard again, using just the TACT switches as doorbell buttons, and it worked fine. So I think my problem is due to the signal not making it back to the arduino.

Is there anyway to increase signal in a length of wire?

[Dirk_H]

Hi,

I assume you use internal pullup from the Arduino and switch to GND with the switch?

In this case you can try to use an external pullup (with dedicated resistor). I'd start with 1k and then try 470Ohm.

If this does not fit your quetion, please try to make a small sketch / diagram about your actual circuit. So we can give more precise answers :)

Greetings
DirkH.

[drock1985]

Hi @Dirk_H

Here is the thread with my project.

http://forum.mysensors.org/topic/2293/how-to-2-door-chime-automation-hack-thanks-petewill

And you are correct, I am using my internal pin-up resistor currently in the sketch. Should I remove it and just add the external resistor, or add the external resistor on to it?

[Dirk_H]

Hi, I'd deactivate the internal pullup when using an external one. But it shouldn't really matter (the internal pullup would just be in parallel with the external one, reducing its value somewhat).

If the external pullup does not work, please check the resistance of the wiring when button is not pressed (shuld be infinite) and when button is pressed with a multimeter.

[drock1985]

Hi,

I'll try that when I get home later, thanks. Where would I put the resistors in the circuit? Closer to the switch, microcontroller, or does it matter?

[Dirk_H]

Hi,
pls do a quick (picture) search for "pullup resistor". It should become clear then. Yor are likely to put it at the microcontroller because you would need 3 cables to your door key when putting the resistor somewhere else :)

[drock1985]

@Dirk_H

Hi,

Thanks for all your help. I got it to work using an external pull-up resistor. I did a check on all my wiring just to make sure all was ok, and it was. The one thing I did get was a resistance on my front doorbell on what I thought was an open circuit; then I realized there was a lamp in the button.

This video helped explain why it works, in a way that I understand at least. https://youtu.be/wxjerCHCEMg

Thanks again @Dirk_H