DRIVER PWM

PWM driver reusable in different platforms.

Supported Hardware

• STM32L552

Functions Guide

• pwm_initialize : used for initialize the peripheral.
• pwm_deinitialize : used for de-initialize the peripheral.
• pwm_start : used for start the peripheral.
• pwm_stop : used for stop the peripheral.
• pwm_set_period : used for set the period (sets the prescaler at 50-1 and the period at 100-1).
• pwm_set_duty_cycle : used for set the duty cycle.
• pwm_set_frequency : used for set the duty cycle.

How to use

• Include the header file drv_pwm.h
• Configure the timer (TIMx) peripheral to operate in PWM mode with CHx output.
• Create the pwm_t instance. The following members of the structure must be defined:
  • instance.handler : handler of choice (ex. &tim1).
  • instance.channel : enabled PWM channel (ex. TIM_CHANNEL_3).
  • instance.mx_init : PWM initializing function generated by the configuration tool (ex. MX_TIM1_Init).

pwm_t hpwm =
{
		.handler =&htim1,
		.channel= TIM_CHANNEL_1,
		.init = MX_TIM1_Init,
		.clock_freq_mhz = 40
};

• Use the function pwm_initialize to initialize the peripheral and pwm_set_duty_cycle to set the desired duty cycle.

Example

Let's consider a NUCLEO - L552ZE-Q. The TIM1 timer peripheral has been configured to operate in PWM mode on channel 3 (TIM_CHANNEL_3).

pwm_initialize(&hpwm); //structure defined above
pwm_start(&hpwm);
pwm_set_period(&hpwm , 100) //the function currently sets the period at 100-1 independetly from the inseryed value
pwm_set_duty_cycle(&hpwm ,20);
pwm_set_frequency(&hpm,15000);
pwm_set_duty_cycle(&hpwm ,75);