Hello,
So I'm trying to read multiple buttons with a demultiplexer IC and arduino. Do I need a pull-up resistor for each of the buttons? Or is there a way that I can save the number of resistors that I need?
Thanks,
mrbook
hi
what kind of multiplexer are you using-- do you have a schematic to share? In general Internal pull-ups are only available on something like a processor... logic chips don't usually include that ability. Resistors are cheap though!
D
Hi Daniel,
I'm using a 4051 to read 8 buttons using 4 arduino pins. I know resistors are cheap, but I want to save myself some soldering time if possible 
Is it possible?
Cheers,
Hector
Hi
that is a CMOS chip, which means it runs on very little current. The typical input current for a read operation of an input pin is 1 microampere: .000001 Amps. I didn't see any pullup resistor option in the datasheet, which means you'll get false readings without pullup resistors.
D