Simple Manual Control of Stepper Motors Without a PIC or PC


Introduction: Simple Manual Control of Stepper Motors Without a PIC or PC

This instructable will show you how to control stepper motors (Unipolar OR Bipolar) manually with a knob, without the use of a PIC or PC, so no programming is needed.  The position of the knob determines the position of the motor shaft, which will stay in that position until the knob is turned again.  The unipolar and bipolar circuits are different, but each requires only 1 chip.


Step 1: Here's What You'll Need.

For the Unipolar board -     (1) rotary encoder

                                                (4) 1K 1/4W resistors

                                                (1) ULN2003 I.C.


For the Bipolar board -        (1) rotary encoder

                                                (2) 1K 1/4W resistors

                                                (2) 10k 1/4w resistors

                                                (2) 2N3904 transistors

                                                (1) L293D I.C. (or equivalent such as SN754410NE)

Step 2: Use Eagle Files (below) or Program of Your Choice to Make the PCB's for Each Board.

Eagle files for Unipolar Board:




Eagle files for Bipolar Board:



Step 3: Populate the Boards. Here Are Pictures of the Completed Boards:

Step 4: Hook Up Your Motor Voltage, +5v Supply, and the Appropriate Motor to the Appropriate Board and Enjoy.

Here is a video of the bipolar board in action:

Step 5: How It Works

The rotary encoder provides 2 square wave type outputs, each 90 degrees out of phase.  Each board converts those to 2 pairs of complementary outputs, which provide the proper sequence for full-step, high torque driving of unipolar or bipolar motors.   (I used the EVQ-WTEF2515B from Electronic Goldmine), but you could use any quadrature type rotary encoder, including those found in computer mice (the scroll wheel).   The sequence is reversed when the rotary encoder is turned the opposite direction.



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40 Discussions

I found Rotary Encoder V Keyes (KY-040 I think), whose image is added. Can you tell me what is the correspondet pins in your bipolar circuit? I'm lost!


Hi. I made bipolar controller and the motor and all the electronics are very hot. Is it ok? I'm using OKI stepper from Epson Stylus Photo 750 printer, as I found it's rated to +42 volts, I'm using only +12 DC and motor is hot. Also encoder from computer mice is not the best choice, control of the motor is not stable.

help me! step motor position control matlab gui pic 16f877a

Would like to build this to control a damper using a 12v stepper, can you suggest mods to your components so I don't have to use a second power supply in my existing 12v equipment

hi, i'm really interested in making this, but i noticed in the video that the motor is quite jerky and was wondering if that is because of the motor or the encoder or the chip. i want to end up with something like this

i dont really know much in this area so i really appreciate the help

1 reply

hi benjaminw , have you found how to made the controler in the video you post ? the opcion showed here is interesting , but i like to know if there is another way to do it. i like to attach a little lamp to the "servant" stepper , and control it remotely from a "master" station some meters away. i'm glad if you share with me and anyone the info you got from these

thanks for yout attention and regards from mexico

hey im just wondering would the bipolar circuit work with an L293e instead of L293d?

I built the unipolar board, works ok. I was wondering if there is any way to wire an absolute encoder instead of incremental? The "slipping" when actuation the encoder is causing me grief.... Also, how many amps at 12v can I put in without damaging the board?.

To do this all you need is another stepper motor. If you hook 2 stepper motors up coil to coil one will run in sympathy to any shaft movement of the other. With absolutely no other circuitry, parts, or even power required. It's like magic!


Can i use rotary encoder form computer mouse.

thanks & regards,

This is exactly what I need except for one thing... I have a stepper motor that is rated for 1.5 amps at 3.5 volts. The ULN2003 would not appear to be able to handle that. Can anyone suggest a different IC that would work for this, but that has the voltage and current range for my motor? Thanks!

Hi, I need to know if a rotary encoder is the same that a variable resistor? Like volume..?

This is an easy proyect and very usefull.
Thank so much! Regards

2 replies

It looks like a potentiometer but it definitely is not. When connected as in this project, is outputs 1's and 0's in the desired sequence.  See attached  documentation.


Thanks!! I'll tray to get it in some electronic home. I'll work with this proyect, soon comments... thanks

Is there a way to make the motor drive faster that the rotary encoder? Simiar to a gear ratio. Example: for one revolution of the rotary encoder i get 3 revolutions of the stepper motor.

This is something i`ve been wanting to do for some time. I have a usb Microscope that i have wanted to create 3 axis manual control (small) platform to attach it to. One question.... can you make it so that if you turn the nob the motor will continue microstepping until you let go? Hope i`m not pushing it to much LOL. Im currently building a 4' X 4' CNC router now.

3 replies

This setup is strictly for manual control. Sounds like you need automatic stepping triggered by a toggle type push button. You should have no trouble finding a circuit on-line to satisfy your needs.

Thanks for your reply and i will try looking for "automatic stepping control" of some kind.

One question...are the boards already mirrored for toner transfer?

a quick, really simple compared to others in net,and really nice for projects...

Thank you.

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