Summary of Simple manual control of stepper motors without a PIC or PC
This instructable explains how to manually control unipolar or bipolar stepper motors using a single rotary encoder and one IC, with no PIC or PC required. The knob’s position directly sets the motor shaft position, which holds until the knob is turned again. Separate simple circuits are provided for unipolar (using ULN2003) and bipolar (using L293D and transistors) motors, along with PCB Eagle files.
Parts used in the Unipolar board:
- Rotary encoder (1)
- 1K 1/4W resistor (4)
- ULN2003 I.C. (1)
Parts used in the Bipolar board:
- Rotary encoder (1)
- 1K 1/4W resistor (2)
- 10K 1/4W resistor (2)
- 2N3904 transistor (2)
- L293D I.C. or equivalent such as SN754410NE (1)
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:
2wireUnipolarFORmicros2wEnc2.sch
2wireUnipolarFORmicros2wEnc2.brd
For more detail: Simple manual control of stepper motors without a PIC or PC
- How does the knob control the motor position?
The rotary encoder position directly determines the motor shaft position, and the shaft stays in that position until the knob is turned again. - Can this be done without a PIC or PC?
Yes, the project is designed to control stepper motors manually without using a PIC or PC. - What IC is used for the unipolar board?
The unipolar board uses a ULN2003 I.C. - What IC or equivalent is used for the bipolar board?
The bipolar board uses an L293D I.C. or an equivalent such as SN754410NE. - How many 1K resistors are needed for the unipolar board?
The unipolar board requires four 1K 1/4W resistors. - What additional components are required for the bipolar board besides the L293D?
The bipolar board requires a rotary encoder, two 1K 1/4W resistors, two 10K 1/4W resistors, and two 2N3904 transistors in addition to the L293D. - Are PCB files provided?
Yes, Eagle schematic and board files for the unipolar board are provided.
