Stepper Motor Speed and Direction Control Without a Microcontroller

In one of my previous Instructables, I showed you how to control a stepper motor's speed using a 555 timer. This project is an upgrade of that one and you will get to know how to control the motor's direction using another 555 timer IC. So, without any further ado, let's get started!

Here is what you will need:

• An A4988 stepper motor driver
• 2 555 timer ICs
• A prototype breadboard
• A 12-volt power supply
• A 5-volt power supply(Conversely, you can also use a voltage regulator with 5-volt output such as an LC805CV)
• A 1kΩ resistor
• 2 10kΩ resistors
• 3 LEDs(Optional)
• 3 330Ω resistors(Optional, for the LEDs)
• A capacitor(0.3uF to 10uF, try experimenting with different capacitors in this range. Capacitors above this range will cause the stepper motor to move very slowly and ones below the range will not allow the motor to move at all. Make sure the capacitors are rated for voltages above 10 volts.)
• A 100kΩ potentiometer
• 2 push-buttons(normally open ones)
• A lot of male to male jumper wires

After plugging on the motor driver, connect the VDD(or VCC) pin to +5vols, GND to, obviously GND and, VMOT to 12 volts. Don't forget to connect the SLP and RST pins together! I used a small jumper for that.

Please note:- For the IC(1), the pin6 needs to be connected to pin 2 of the chip.

Please move to the next step before starting making the circuit.

Set up and wire only the speed controller. Connect the DIR pin of the motor driver to either GND or +5 volts while testing. Power up your circuit and check whether it is working properly. If there is any problem, the troubleshooting will be easier than it would be after wiring the direction controller.

I hope you enjoyed making this project. I would like to see your what you built. Suggestions are welcome!