Can a STM32 timer generate multiple PWM signals?

Can a STM32 timer generate multiple PWM signals?

A single STM32 timer usually has multiple channels (4, 6, or whatever found in the datasheet). Therefore, using a single timer you can independently generate multiple PWM signals with different duty cycles of course, but they’ll share the same timing (same frequency), and all of them will be in sync.

Which is the most important property of a PWM signal?

One of the most important properties for a PWM signal is the resolution. It’s the number of discrete duty cycle levels that you can set it to. This number determines how many steps the duty cycle can take until it reaches the maximum value.

How to generate PWM in edge-aligned mode STM32?

In PWM mode (1 or 2), TIMx_CNT and TIMx_CCRx are always compared to determine whether TIMx_CCRx≤TIMx_CNT or TIMx_CNT≤TIMx_CCRx (depending on the direction of the counter). The timer is able to generate PWM in edge-aligned mode or center-aligned mode depending on the CMS bits in the TIMx_CR1 register.

What are the capture and compare channels in STM32?

Each Capture/Compare channel is built around a capture/compare register (including a shadow register), an input stage for capture (with a digital filter, multiplexing, and Prescaler) and an output stage (with comparator and output control). The output stage generates an intermediate waveform which is then used for reference: OCxRef (active high).

Where does the default clock come from on the STM32?

The default clock comes from the reset and clock controller, linked to one of APB clock domains. The various timers are shared on the 2 APB domains to implement low-power schemes (typically one high-speed APB and one low-speed APB to limit the current drawn by the peripherals, including the timers).

What does a prescaler do in a STM32 timer?

It can have a Prescaler to divide the input clock frequency by a selectable value. It can also have circuitry for input capture, PWM signal generation, and much more as we’ll see in this tutorial.

What are the duty cycles in STM32 clock generator?

For the PWM setting, on the other hand, the setting is the actual effective value (not +1). The duty cycles are 45.1%, 64.7%, 13.7%, and 5.9%, respectively. (I have a similar setup for a different STM32 processor, but also set up with STM32CubeMX and compiled/run under OpenSTM32.

How to generate a fixed duty cycle signal?

To generate a fixed duty cycle PWM signal I added HAL_TIM_Base_Start (&htim1); //Starts the TIM Base generation and HAL_TIM_PWM_Start (&htim1, TIM_CHANNEL_1)//Starts the PWM signal generation to the Timer initialization function as shown below.

How is the duty cycle of a PWM determined?

Whose frequency is determined by the internal clock, the Prescaler, and the ARRx register. And its duty cycle is defined by the channel CCRx register value. The PWM doesn’t always have to be following this exact same procedure for PWM generation, however, it’s the very basic one and the easier to understand the concept.

Why does the Hal timer interrupt the PWM signal?

I tried that and obtained weird waveforms on the oscilloscope, but that might be because The ADC pins where floating, causing floating measurements to interfere with the duty cycle by the algorithm. Also recalling the initialization of the timer continuously would interrupt the PWM signal.

Which is the maximum pulse length in STM32F4?

Based on the equation, pulse length is maximum at 100% duty cycle <==> which gives us pulse length = TIM_period. I have a situation where I am unable to get the desired pulse length.

Is the Hal source available for STM32F4?

The entire point of the HAL is to not have to worry so much about the details, but you’ve got to have a good handle on what the HAL is doing and what it’s expecting. The full source is available and is fairly well documented.

How does the ADC work on the STM32?

The ADCs can be triggered with most of the STM32 timers, with three options. This can be done using compare events: the ADC conversion will start on a given compare match. The list of supported compare events varies from one timer to the other, as shown on the table. The TRGO event can also be used on certain timers.

What can variable PWM signal be used for?

Variable PWM signal is used for controlling the speed of DC motors/Fans. It is also used in AC Light Dimmer. PWM solar chargers also work on variable PWM signal. Servo Motors angle and direction is also controlled with the PWM signal. In this tutorial, we will learn about PWM (Pulse Width Modulation) in STM32 using Servo Motor.

What is the maximum PWM resolution of STM32?

It has 16-bit PWM resolution, i.e 2^16. Because of this its counters and variables can be as large as 65535. As it has 72MHz clock rate, its PWM output can have a maximum period of about one millisecond. 1. The value of 65535 gives Full Servo Rotation (100% Duty Cycle)

How does PWM work in a microcontroller?

We know that all microcontrollers work on digital domain and accessing or producing analog signal is not directly possible. PWM, which is short for Pulse Width Modulation, is a technique to produce analog signal using digital means. This is done by making a digital Output pin HIGH and LOW at a certain frequency to produce a square wave.