Instructables

2 uln2003 stepper drivers linked

Lots of build yer own stepper motor driver boards here. CNC also but, I  have these little ULN2003 driver boards that come with the small BLJ steppers...you do too.  I've seen linking 2 SF easy steppers together but, those cost. anyone know how to tie these cheapy driver boards together-to drive 2 stepper motors with few  /fewer pins from the microcontroller to drive 'em? would some sort of shift register arrangement be in play here?

Picture of 2 uln2003 stepper drivers linked
schel (author) 4 months ago

AHHH-HAAAaa! Check this!! So, Yes there are more than 4 outs on a 'duino..but, theres only 1 each of MOSI,MISO,SCK ..oui? steppers need these in their hookup in normal situations...so using multiples becomes an issue. The image shows how to do 2 wires to the MC! theres more on this site for using LM293Ds to run multiple steppers and regular motors with minimal pins used!!! Thanks ya'll for lookin'!!

http://www.tigoe.net/pcomp/code/circuits/motors/stepper-motors/

unipolar_stepper.png

I opeted for the 2013 simce it support 8 lines which means two stepper ,otors at 4 lines cach.

mpilchfamily4 months ago

Do a quick search. I googled uln2003 driver board arduino and found many articles and images showing you how to connect them and use them on an arduino.

Here is a good place to start.The drivers only need 4 pins going to the arduino and of course the power and ground.

http://www.geeetech.com/wiki/index.php/Stepper_Mot...

schel (author)  mpilchfamily4 months ago
Thanks for your efforts MP! but, I know how to hook 'em up silly!
I wanna know how to hook up multiples! As is 1 of these takes up all the available / necessary arduino pins so, to hook up 2-4 is a different issue. From what I've seen Googlin' the ulns' need to be linked together - this is the question- and then linked to the 4 + arduino pins.

I dont want to have to use 2 arduinos to have two steppers work and the shift register breakouts cant supply enough V to multiple motors smoothly.
I really want to use these little boards instead of building a new driver board ie: cnc type deal.
Thanks for lookin' though! thats why I love Instructables soooo MUCH...Someone will step up with answers for others projects!

Your arduino has more than 4 pins on it. Just a matter of adapting the code to include the pins used for the second driver. Only other change i would recommend is using an outside power source for the motors. As you know the of 2 of them will pull more amperage than the arduino can provide. So use a separate power source to run the divers. Just be sure to link the ground of that source with the ground of the arduino.