Question about "active low"

Using Arduino General Electronics
#1

You probably know by the title what my question is. If a little Bluetooth module has a reset pin that is active low, do I connect it (via a momentary SW) to ground or to Vcc to be able to push the momentary switch to reset it?

#2

Ground. - Scotty

#3

You pull it up to Vcc with a resistor (typically 10K), so when "idle" it is "high".

Then a pushbutton connects it to ground, so when you "activate" the pin you send it "low".

#4

could you just use the internal resistor by turning the pin HIGH with a digitalWrite? instead of connecting it to a V+ via resistor?

#5

You could but if you read what was said:-

If a little Bluetooth module has a reset pin that is active low, do I connect it (via a momentary SW) to ground

The OP is not using an arduino pin to do the resetting.

#6

ah...got it.

I mis-read it as making the pin LOW via Arduino was resetting it.

thanks!

#7

majenko: You pull it up to Vcc with a resistor (typically 10K), so when "idle" it is "high".

Then a pushbutton connects it to ground, so when you "activate" the pin you send it "low".

This is what I thought. But it pays to ask questions while working in eagle design, rather than holding the soldering iron in hand... Thanks!

#8