Code is written by utilizing stm32 HAL libraries. Keil arm mdk 5 is used for writing and compiling the project code. Stm32cubemx is used for stm32f103c8t6 microcontrollers gpio, timers configuration. St32f103c8t6 micorcontroller pre assembled board is used in the project. Pwm technique is utilized in the project to control the motor speed and direction. In this project our purpose is to control the speed of motor with stm32 microcontroller.

In pulse width modulation input constant voltage to motor is divided in to sub cycles to reduce the amount of input voltage. To achieve the upper logic pwm(pulse width modulation) technique is best suited. But if we want to insert some control logic(e.g changing motor rotation direction) or accurately control the motors rpm (resolutions per minute) then variable resistor technique can not full fill our requirement. Variable resistor is a good choice to control motor speed. The resistor varies the power when we rotate its knob in either directions. Like our roof fans(work on Ac voltage) rotating speed is controlled by varying the potentiometer(variable resistor) connected in the buttons socket. By variable voltage i mean to supply less amount of voltage(power) than maximum rating of a particular dc motor. One such technique and the most popular is to supply a variable voltage to it. DC motors rotate at a constant speed but their speed can be varied and controlled by utilizing few techniques. Dc motors are common motors you see in your houses(DC water pumps, DC fans), toys etc.

In this tutorial i am going to teach you how to control speed of dc motor using stm32 microcontroller and l293d half h bridge control ic.

Speed controller for motor