How to calculate counter period for PWM in STM32?

How to calculate counter period for PWM in STM32?

However, I need to create PWM with 200 KHz frequency and the clock of the timer is 72 MHz.In order to achieve a value of 100 in counter period I need to have a 3.6 prescaler. Am I following a wrong way or did I get this PWM duty cycle thing wrong in stm32?

How to generate variable duty cycle PWM with DMA?

I use the Blue pill STM32F103C8T6 to generate variable duty cycle PWM with DMA and using HAL library. And stuck with undesired results. First, I generated code with STM32CubeMX v5.0.1, HAL v1.7.0, with TIM1 configured to generate PWM on channel 1 with DMA (internal clock, prescaler 71, period 999), and with LED at pin C13 for debugging.

How is the output waveform controlled in STM32?

And in this case, the output waveform’s frequency is controlled by changing the delay period (x). Another way is to use Timer interrupts to periodically fire an interrupt signal so that the CPU can transfer the data points to the CCRx in a periodic manner. However, it’s a more efficient way than the previous one.

How are timer interrupts used in STM32?

Another way is to use Timer interrupts to periodically fire an interrupt signal so that the CPU can transfer the data points to the CCRx in a periodic manner. However, it’s a more efficient way than the previous one. But it still requires a lot of CPU intervention, especially when a high sampling rate is required.

What is the timing resolution of a PWM clock?

I can use a prescaler setting of divide by 8 and a period counter modulus of 60,000 for a PWM period of 20 milliseconds. Now we know the timing resolution for the output pulse. The timing resolution is the period of the 3 MHz clock or 0.333 microseconds.

How does a PWM timer in a microcontroller work?

A PWM timer block diagram A clock is divided down by a prescaler and applied to a period counter. The duration of the period counter is set with a modulus or period register. The output of the period counter goes to multiple “channels” of pulse width logic.

How are all four PWM channels the same?

Thus, all four channels will share the same period (PWM frequency), but can have individual duty-cycle and polarity. The polarity is set by the value read from RAM (see Figure 4 ), while the MODE register controls if the counter counts up, or up and down.

Which is STM32 LED dimmer operates in PWM mode?

STM32 PWM Example LED Dimmer Set up timer 2 to operate in PWM mode with the internal clock. And enable CH1 to be the PWM output channel. Set the ARR value to the maximum 65535 for example, so the frequency should be 1098Hz

What is maximum fpwm frequency for STM32 PWM mode?

The auto-reload register will be set to a maximum value which is 65535, for no particular reason. But you should know that the output FPWM frequency is expected to be 1098.6Hz from the equation we’ve seen earlier. And the PWM resolution is estimated to be 16-Bit which is the maximum possible value for this module.

How to use PWM in stm32f103c8t6?

PWM in STM32F103C8T6 If you remember the “Getting Started with STM32F103C8T6” tutorial, I have pointed out that the STM32 Blue Pill board has 15 Pins capable of generating PWM Signals. The resolution of the PWM in STM32F103C8T6 is of 16-bit i.e. the maximum counter value is 216, which is equal to 65535.