Hi my name is GerryK

Welcome Gerry! I claim to be a developer by day, and there are also numerous people here who can also help you out with your code.

@gpdkeogh

Welcome to the forum.

I've used BYJ motors with the basic ULN drivers, but never had  need to home them.

What questions do you have ?

question: Yes I am using the ULN2003 driver chip with the Arduino Uno R3 board.  I am trying to find a way to use magnetic hall effect switch to zero the position on start-up of the stepper motor. Once find zero immediately stop. A toggle switch moves the stepper forward 1/4 motor revolution (2048 steps / 4).  What is the best software approach to use?  While loop??

@gpdkeogh 

I would just rotate the BYJ stepper (fairly slowly) until the Hall sensor goes HIGH and then set your location to zero.

I don't know your layout so I can't comment on how to position the sensor. I presume that your stepper shaft drives a magnet through some kind of path and that, on startup, you need the position to be set to a known location. If you position the magnet at a point where it just triggers the sensor when it's properly situated, then you're finished.

Using a toggle switch will be frustrating and inaccurate.

So, if your Hall sensor is on pin hallPin ...

while (!digitalRead(hallPin)) {

    ... // advance one or more steps depending on the accuracy required

}

position = 0;    // At starting location

This will rotate the shaft until the Hall sensor goes high which is, I think, what you wanted.

Note that this can also be used at any time during operation if you need to reset the device.

hope this helps.