Go Down

Topic: Potentiometer instead of restitors for LDR (Read 614 times) previous topic - next topic

Krisztian Hofstadter

I've posted this in a wrong subgroup before [audio], but I think it belongs here instead:

Hello,
I wonder whether it is possible to use a pot instead of 6 resisors that are helping with LDRs.
Basically, I wouldn't like to change a software mapping every time the installation is in another room with differenent brightness (or light coming from a projector) and thought that if it is possible to swap the 6 resistors to 1 pot I then could adjust the resistance and have an easier life. Is this possible?

thanks and all the best, K

WizenedEE

I think you might be able to do it with 3 if you hooked 5V to the middle, one LDR to one side, and another to the other side. You'd have to "invert" (subtract from 1024) three of them in code, though.

Krisztian Hofstadter

thanks, hmm... sounds interesting, but more difficult than I thought I would be...

Grumpy_Mike

No just replace the resistors with a pot, wiper and one end to plus, other end to the LDR.
If it were me however I would put a fixed resistor in seriese with it as well to make sure you never got too much current down the LDR.

Krisztian Hofstadter

hello Mike,
I will give this a go, thanks. k

Go Up