Education

Methods To Control Servo Motors

Photo by Igor Karimov on Unsplash

Photo by Igor Karimov on Unsplash

Your new servo motor for your project is an excellent piece of equipment. However, you want to learn about other hardware options to equip it with. In this article, different methods to control your servo motor will be discussed. It includes an overview of which of these methods will suit best for your project. How do servo motors follow instructions? Before you intend to command your servo motor, you must learn how to communicate with it. The best asset of a working control system is mutual understanding, including the input and output qualities. In this instance, you will understand the signals used by your servo motor.

What signals does your servo motor understand?

Usually, servo motors have three input wires: two power lines and one signal line. The two power lines are generally for a continuous power supply, like what a conventional electric motor needs. The signal line, however, needs electrical pulses called PWM (pulse width modulation). These pulses are a couple of milliseconds long and are continuously supplied to the signal. These pulses are sent to your servo motor at frequencies around 50Hz (a pulse every 20ms).

How can you use this signal to position your servo motor?

The duration of these pulses called “duty cycle” corresponds to servo motor shaft angular positions. Let’s say that the range of the pulses is 1~2ms, and your servo motor has extreme positions of -90 and +90 degrees. 1ms will move the shaft to -90 degrees, and 2ms will tell it to go to the +90 degrees. After learning the servo motor language, you can learn about the electronics used to supply these pulses to your servo motor.

  1. Servo Microcontroller

Unit If your project involves using a microcontroller unit, using it for your servo motor is the easiest method. You can easily program it and connect it to several servo motors and other devices. Also, there are several suppliers available online, given that one of the leaders provides servo motors together with microcontrollers. It is one of the best methods up to date, allowing your project for future upgrades.

  1. Astable Vibrator Circuit

If you have spare time and a low budget, making an astable vibrator using a 555-timer is enough. It is merely a hardwired circuit that produces PWM signals, controlled by a potentiometer. However, it is not cost-effective when you need to upgrade, or you need to manage several motors. Due to the research and assembly stages, it is the best way to learn servo motor control.

  1. Dedicated Controller IC

The last method is to use a dedicated controller IC, enabling simultaneous control of several servo motors. It is best suitable for projects involving complicated motion control. There is a considerable number of choices in the market, considering the maximum number of servos and various ways of operations. However, a controller IC alone cannot be programmed, requiring a microcontroller unit to make your project run.

Summary

You probably already figured that out, but it would be best to review it as a summary. If your project is simple, use an astable vibrator. Use a microcontroller if your project needs flexibility, requiring a dedicated controller IC for projects with several servo motors. Hopefully, this helps you choose the proper items for your project.

Leave a Comment