Pulling Multiple Pins High/Low

[hurricane478]

Hello all,

I am short on pins for my Arduino project but some of my components have pins that will always be pulled high/low for my project. These components are the A4988 stepper controller and the TB6612FNG motor controller.

I was planning to keep these pins low:
A4988 reset pin
TB6612FNG AIN1, BIN2

I was planning to keep these pins high:
TB6612FNG AIN2, BIN1

I was initially planning on using a pull-up/down resistor on each connection and connect them 5V/ground respectively, but I wondered could I use a single resistor connected to positive of my 5V power supply and then connect all the pins that I want to pull high to that resistor? And then the same for the negative to pull pins low?

Essentially do this:

Instead of this:

Of course I would need to change the value of the resistor, but otherwise would this be fine?

Edit: adding circuit diagrams.

[DVDdoug]

The resistor can be shared. It's done "everyday."

Or, in most cases you can connect directly to Vcc or ground. For some reason it's not commonly done but I've got some switches with pull-ups and the switch can be on (switching the input solidly to ground) essentially "forever" and that's OK.

I would need to change the value of the resistor,

Not necessarily. There is virtually no current flowing so in most cases the resistor has to be low-enough to minimize noise pickup.

And if there is a switch or connected output-line, the resistance has to be high-enough that excess current doesn't flow when switched to "overpower" the pull-up or pull-down resistor.

...A wide range of resistor values will work.

[hurricane478]

Fantastic, this makes my life easy. Thanks for being so quick.

[camsysca]

@DVDdoug

Or, in most cases you can connect directly to Vcc or ground.

One consideration. If there's a chance that you might want to use one of those pins "down the road", you should consider either giving them a separate pullup, or alternatively at least providing a jumper pad on the board(presuming you're doing a circuit board). Oh, and at a bare minimum, make sure you don't 'bury' the wires for those pins on an internal layer, or under the device itself, so it's easier to make those mods in future. You just never know...

[hurricane478]

I have a 5V step down converter as I need more current capacity than Vcc can do, so I will most likely take the 5V + and - terminals with a resistor to make a pull up/down station.