/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
files (startup_stm32f40_41xxx.s/startup_stm32f427_437xx.s/startup_stm32f429_439xx.s)
before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f4xx.c file
*/
/* TIM Configuration */
TIM_Config();
/* -----------------------------------------------------------------------
TIM3 Configuration: generate 4 PWM signals with 4 different duty cycles.
In this example TIM3 input clock (TIM3CLK) is set to 2 * APB1 clock (PCLK1),
since APB1 prescaler is different from 1.
TIM3CLK = 2 * PCLK1
PCLK1 = HCLK / 4
=> TIM3CLK = HCLK / 2 = SystemCoreClock /2
To get TIM3 counter clock at 21 MHz, the prescaler is computed as follows:
Prescaler = (TIM3CLK / TIM3 counter clock) - 1
Prescaler = ((SystemCoreClock /2) /21 MHz) - 1
To get TIM3 output clock at 30 KHz, the period (ARR)) is computed as follows:
ARR = (TIM3 counter clock / TIM3 output clock) - 1
= 665
TIM3 Channel1 duty cycle = (TIM3_CCR1/ TIM3_ARR)* 100 = 50%
TIM3 Channel2 duty cycle = (TIM3_CCR2/ TIM3_ARR)* 100 = 37.5%
TIM3 Channel3 duty cycle = (TIM3_CCR3/ TIM3_ARR)* 100 = 25%
TIM3 Channel4 duty cycle = (TIM3_CCR4/ TIM3_ARR)* 100 = 12.5%
Note:
SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f4xx.c file.
Each time the core clock (HCLK) changes, user had to call SystemCoreClockUpdate()
function to update SystemCoreClock variable value. Otherwise, any configuration
based on this variable will be incorrect.
----------------------------------------------------------------------- */
/* Compute the prescaler value */
PrescalerValue = (uint16_t) ((SystemCoreClock /2) / 21000000) - 1;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 665;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* PWM1 Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Enable);
/* PWM1 Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;
TIM_OC4Init(TIM3, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(TIM3, ENABLE);
/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);
while (1)
{}
}
/********
功能：配置PWM_TIMER 为PWM模式输出
计数频率为TIM_FREQ,PWM周期为PWM_PERIOD,初始占空比为0
********/
void Servo_TIM_PWM_Init(void)
{
uint16_t CCR_Val = 1500;
int PrescalerValue=1;
GPIO_InitTypeDef GPIO_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
//TIM clock enable
//根据TIM选择使能不同的时钟
if((PWM_TIMER == TIM2) || (PWM_TIMER == TIM3)||(PWM_TIMER == TIM4) ||
(PWM_TIMER == TIM5)||(PWM_TIMER == TIM6) || (PWM_TIMER == TIM7))
{
RCC_APB1PeriphClockCmd(PWM_TIMER_CLK, ENABLE);
}
if((PWM_TIMER != TIM1) && (PWM_TIMER != TIM8))
{
RCC_APB2PeriphClockCmd(PWM_TIMER_CLK, ENABLE);
}
//enable GPIO clocks
RCC_APB2PeriphClockCmd(
PWM_OUT_PORT_CLK |
RCC_APB2Periph_AFIO,ENABLE);
//配置相应的GPIO输出
GPIO_InitStructure.GPIO_Pin=PWM_OUT_PIN1|PWM_OUT_PIN2|PWM_OUT_PIN3|PWM_OUT_PIN4;
GPIO_InitStructure.GPIO_Mode=GPIO_Mode_AF_PP;
GPIO_InitStructure.GPIO_Speed=GPIO_Speed_50MHz;
GPIO_Init(PWM_OUT_PORT,&GPIO_InitStructure);
//配置TIMER 分频系数 计数周期 工作模式
PrescalerValue= (uint16_t)(SystemCoreClock/TIM_FREQ-1);
TIM_TimeBaseStructure.TIM_Period = PWM_PERIOD-1;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(PWM_TIMER , &TIM_TimeBaseStructure);
//PWM模式配置 通道1
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(PWM_TIMER , &TIM_OCInitStructure);
TIM_OC1PreloadConfig(PWM_TIMER , TIM_OCPreload_Enable);
//通道2
TIM_OCInitStructure.TIM_Pulse = CCR_Val;
TIM_OC2Init(PWM_TIMER , &TIM_OCInitStructure);
TIM_OC2PreloadConfig(PWM_TIMER , TIM_OCPreload_Enable);
//通道3
TIM_OCInitStructure.TIM_Pulse = CCR_Val;
TIM_OC3Init(PWM_TIMER , &TIM_OCInitStructure);
TIM_OC3PreloadConfig(PWM_TIMER , TIM_OCPreload_Enable);
//通道4
TIM_OCInitStructure.TIM_Pulse = CCR_Val;
TIM_OC4Init(PWM_TIMER , &TIM_OCInitStructure);
TIM_OC4PreloadConfig(PWM_TIMER , TIM_OCPreload_Enable);
TIM_ARRPreloadConfig(PWM_TIMER , ENABLE);
/* TIM enable counter */
TIM_Cmd(PWM_TIMER , ENABLE);
}
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f2xx.s) before to branch to application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f2xx.c file
*/
/* TIM Configuration */
TIM_Config();
TIM_TimeBaseStructInit(&TIM_TimeBaseStructure);
TIM_OCStructInit(&TIM_OCInitStructure);
/* ---------------------------------------------------------------------------
TIM3 Configuration: Output Compare Active Mode:
In this example TIM3 input clock (TIM3CLK) is set to 2 * APB1 clock (PCLK1),
since APB1 prescaler is different from 1.
TIM3CLK = 2 * PCLK1
PCLK1 = HCLK / 4
=> TIM3CLK = HCLK / 2 = SystemCoreClock /2
To get TIM3 counter clock at 1 KHz, the prescaler is computed as follows:
Prescaler = (TIM3CLK / TIM3 counter clock) - 1
Prescaler = ((SystemCoreClock /2) /1 KHz) - 1
Generate 4 signals with 4 different delays:
TIM3_CH1 delay = CCR1_Val/TIM3 counter clock = 1000 ms
TIM3_CH2 delay = CCR2_Val/TIM3 counter clock = 500 ms
TIM3_CH3 delay = CCR3_Val/TIM3 counter clock = 250 ms
TIM3_CH4 delay = CCR4_Val/TIM3 counter clock = 125 ms
Note:
SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f2xx.c file.
Each time the core clock (HCLK) changes, user had to call SystemCoreClockUpdate()
function to update SystemCoreClock variable value. Otherwise, any configuration
based on this variable will be incorrect.
--------------------------------------------------------------------------- */
/*Compute the prescaler value */
PrescalerValue = (uint16_t) ((SystemCoreClock / 2) / 1000) - 1;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = PrescalerValue;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* Output Compare Active Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Active;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable);
TIM_ARRPreloadConfig(TIM3, DISABLE);
/* Output Compare Active Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Active Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Active Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;
TIM_OC4Init(TIM3, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);
TIM_GenerateEvent(TIM3, TIM_EventSource_Update);
/* Turn on LED1 */
STM_EVAL_LEDOn(LED1);
while (1)
{}
}
/**
* @brief Main program
* @param None
* @retval None
*/
int main(void)
{
/*!< At this stage the microcontroller clock setting is already configured,
this is done through SystemInit() function which is called from startup
file (startup_stm32f40xx.s/startup_stm32f427x.s) before to branch to
application main.
To reconfigure the default setting of SystemInit() function, refer to
system_stm32f4xx.c file
*/
/* TIM Configuration */
TIM_Config();
/* -----------------------------------------------------------------------
TIM3 Configuration: Output Compare Timing Mode:
In this example TIM3 input clock (TIM3CLK) is set to 2 * APB1 clock (PCLK1),
since APB1 prescaler is different from 1.
TIM3CLK = 2 * PCLK1
PCLK1 = HCLK / 4
=> TIM3CLK = HCLK / 2 = SystemCoreClock /2
To get TIM3 counter clock at 6 MHz, the prescaler is computed as follows:
Prescaler = (TIM3CLK / TIM3 counter clock) - 1
Prescaler = ((SystemCoreClock /2) /6 MHz) - 1
CC1 update rate = TIM3 counter clock / CCR1_Val = 146.48 Hz
==> Toggling frequency = 73.24 Hz
C2 update rate = TIM3 counter clock / CCR2_Val = 219.7 Hz
==> Toggling frequency = 109.8 Hz
CC3 update rate = TIM3 counter clock / CCR3_Val = 439.4 Hz
==> Toggling frequency = 219.7 Hz
CC4 update rate = TIM3 counter clock / CCR4_Val = 878.9 Hz
==> Toggling frequency = 439.4 Hz
Note:
SystemCoreClock variable holds HCLK frequency and is defined in system_stm32f4xx.c file.
Each time the core clock (HCLK) changes, user had to call SystemCoreClockUpdate()
function to update SystemCoreClock variable value. Otherwise, any configuration
based on this variable will be incorrect.
----------------------------------------------------------------------- */
/* Compute the prescaler value */
PrescalerValue = (uint16_t) ((SystemCoreClock / 2) / 6000000) - 1;
/* Time base configuration */
TIM_TimeBaseStructure.TIM_Period = 65535;
TIM_TimeBaseStructure.TIM_Prescaler = 0;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
/* Prescaler configuration */
TIM_PrescalerConfig(TIM3, PrescalerValue, TIM_PSCReloadMode_Immediate);
/* Output Compare Timing Mode configuration: Channel1 */
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_Timing;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR1_Val;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Timing Mode configuration: Channel2 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR2_Val;
TIM_OC2Init(TIM3, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Timing Mode configuration: Channel3 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR3_Val;
TIM_OC3Init(TIM3, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* Output Compare Timing Mode configuration: Channel4 */
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = CCR4_Val;
TIM_OC4Init(TIM3, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(TIM3, TIM_OCPreload_Disable);
/* TIM Interrupts enable */
TIM_ITConfig(TIM3, TIM_IT_CC1 | TIM_IT_CC2 | TIM_IT_CC3 | TIM_IT_CC4, ENABLE);
/* TIM3 enable counter */
TIM_Cmd(TIM3, ENABLE);
while (1);
}
/*
* @brief Should take an integer 0-255 and create a PWM signal with a duty cycle from 0-100%.
* TIM_PWM_FREQ is set at 500 Hz
*/
void analogWrite(uint16_t pin, uint8_t value)
{
if (pin >= TOTAL_PINS || PIN_MAP[pin].timer_peripheral == NULL)
{
return;
}
// SPI safety check
if (SPI.isEnabled() == true && (pin == SCK || pin == MOSI || pin == MISO))
{
return;
}
// I2C safety check
if (Wire.isEnabled() == true && (pin == SCL || pin == SDA))
{
return;
}
// Serial1 safety check
if (Serial1.isEnabled() == true && (pin == RX || pin == TX))
{
return;
}
if(PIN_MAP[pin].pin_mode != OUTPUT && PIN_MAP[pin].pin_mode != AF_OUTPUT_PUSHPULL)
{
return;
}
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
//PWM Frequency : 500 Hz
uint16_t TIM_Prescaler = (uint16_t)(SystemCoreClock / 24000000) - 1;//TIM Counter clock = 24MHz
uint16_t TIM_ARR = (uint16_t)(24000000 / TIM_PWM_FREQ) - 1;
// TIM Channel Duty Cycle(%) = (TIM_CCR / TIM_ARR + 1) * 100
uint16_t TIM_CCR = (uint16_t)(value * (TIM_ARR + 1) / 255);
// AFIO clock enable
RCC_APB2PeriphClockCmd(RCC_APB2Periph_AFIO, ENABLE);
pinMode(pin, AF_OUTPUT_PUSHPULL);
// TIM clock enable
if(PIN_MAP[pin].timer_peripheral == TIM2)
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM2, ENABLE);
else if(PIN_MAP[pin].timer_peripheral == TIM3)
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
else if(PIN_MAP[pin].timer_peripheral == TIM4)
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
// Time base configuration
TIM_TimeBaseStructure.TIM_Period = TIM_ARR;
TIM_TimeBaseStructure.TIM_Prescaler = TIM_Prescaler;
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(PIN_MAP[pin].timer_peripheral, &TIM_TimeBaseStructure);
// PWM1 Mode configuration
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OCInitStructure.TIM_Pulse = TIM_CCR;
if(PIN_MAP[pin].timer_ch == TIM_Channel_1)
{
// PWM1 Mode configuration: Channel1
TIM_OC1Init(PIN_MAP[pin].timer_peripheral, &TIM_OCInitStructure);
TIM_OC1PreloadConfig(PIN_MAP[pin].timer_peripheral, TIM_OCPreload_Enable);
}
else if(PIN_MAP[pin].timer_ch == TIM_Channel_2)
{
// PWM1 Mode configuration: Channel2
TIM_OC2Init(PIN_MAP[pin].timer_peripheral, &TIM_OCInitStructure);
TIM_OC2PreloadConfig(PIN_MAP[pin].timer_peripheral, TIM_OCPreload_Enable);
}
else if(PIN_MAP[pin].timer_ch == TIM_Channel_3)
{
// PWM1 Mode configuration: Channel3
TIM_OC3Init(PIN_MAP[pin].timer_peripheral, &TIM_OCInitStructure);
TIM_OC3PreloadConfig(PIN_MAP[pin].timer_peripheral, TIM_OCPreload_Enable);
}
else if(PIN_MAP[pin].timer_ch == TIM_Channel_4)
{
// PWM1 Mode configuration: Channel4
TIM_OC4Init(PIN_MAP[pin].timer_peripheral, &TIM_OCInitStructure);
TIM_OC4PreloadConfig(PIN_MAP[pin].timer_peripheral, TIM_OCPreload_Enable);
}
TIM_ARRPreloadConfig(PIN_MAP[pin].timer_peripheral, ENABLE);
// TIM enable counter
TIM_Cmd(PIN_MAP[pin].timer_peripheral, ENABLE);
}