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Oct 5, 2014 · Depending on the clock, prescaler and auto reload, repetition counter (if present) parameters, the 16-bit timer can generate an update event from a nanosecond to a few minutes. For example, to generate an event two times per second, choose Clock frequency(TIM_CLK) = 168 Mhz, Prescalar(PSC) = 16799, Period(ARR) = 4999, repetition counter(RCR) = 0,
Aug 28, 2022 · The prescaler is used to set the frequency in which counter is changed. Example: If your timer clock is 100MHz and you want the timer to overflow every 2ms you need to do some math. For 2ms your counter will have to count to 100MHZ * 2ms = 200000. Most STM32 timers counters are 16 bits and this value will not fit. The maximum value is 65535.
If you want 10Hz, please try to set prescaler = 59999, period = 27; then the timer will work as. f = 168 MHz (59999 + 1) ⋅ (27 + 1) = 100 Hz f = 168 M H z (59999 + 1) ⋅ (27 + 1) = 100 H z. It's a rule from STM specification. Your Answer. Thanks for contributing an answer to Electrical Engineering Stack Exchange!
Dec 1, 2015 · I need to set the timer so that it ticks every 1µs and has a period of 40ms (so counts 40, 000 ticks before overflowing). TIM4 has a source clock speed of 84MHz. The datasheet says: "16-bit programmable prescaler used to divide the counter clock frequency by any factor between 1 and 65536". However in most tutorials divide by 84 - 1 to obtain ...
Sep 12, 2021 · See if you like this version better. A set of two integer factor (X & Y), that produce closest integer to a real number (N).
Jul 9, 2015 · setting the frequency of a PWM on a STM32. I'm trying to write a function that takes a desired frequency of PWM and sets the timer based on this value: RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE); TIM_TimeBaseInitTypeDef timerInitStructure; timerInitStructure.TIM_Prescaler = 1000; timerInitStructure.TIM_CounterMode = TIM_CounterMode_Up;
May 10, 2017 · 2. I am trying to achieve 32-bit resolution using 16-bit timer on STM32F103. I found that ST provides an application note AN2592, however, I have two concerns regarding it: 1) I don't understand why are they multiplying MSB by 65535 (see 3.1). Shouldn't it be 65536 instead (assuming I use period of 65535)?
May 23, 2018 · Your sample frequency is let's say 50 Hz. Calculatel the difference of the encoder values. Than divide by 2000 (ppr).
Feb 17, 2021 · The problem. the STM32 has 2 different registers for this purpose. while the AVRs had a single OCR register, the STM32 has the TOP value set by ARR (auto-reload register) and the output control with CCR (capture/compare register). so when we want to variate the frequency, we have to set both registers; ARR for the frequency and the CCR for just ...
Mar 16, 2020 · So for the STM32, the actual calculation depends on which clock source is feeding your timers, either APB1 (max 60MHz) or APB2 (max 30MHz). In your case, this is APB1. So the counter clock frequency is 60,000,000 / 30,000 = 2,000Hz. This gives you a .5ms on the clock for each "count".
