Servo control using STM32VLDiscovery

[choky_ndhie27]

Posted on October 13, 2011 at 14:18

Hi all,

I 

want to run

 

a

 

servo

 

using the

 

STM32

 

Discovery

, 

if

 

you

 

have a

 

suggestion

 

program to

run

 

the

 

servo

?

or

 

you have a

 

simple

 

code to

 

run the

 

servo

 

on the

 

STM32

 

Discovery

Thank you

Regards,Endy

[choky_ndhie27]

Posted on October 14, 2011 at 13:38

Thanks clive1

,

 

this

 

program

 

can

 

run

 

according to

 

what I want

[Tesla DeLorean]

Posted on December 15, 2011 at 22:47

Ok, based on some email I got on this, here is a 4 channel framework

// STM32 4-channel Servo Demo for 24 MHz VL Discovery - sourcer32@gmail.com
#include ''stm32F10x.h''
#include ''STM32vldiscovery.h''
/**************************************************************************************/
void RCC_Configuration(void);
void GPIO_Configuration(void);
void NVIC_Configuration(void);
void TIM3_Configuration(void);
/**************************************************************************************/
volatile int servo_angle[4] = { 0, 0, 0, 0 }; // +/- 90 degrees, use floats for fractional
void TIM3_IRQHandler(void)
{
if (TIM_GetITStatus(TIM3, TIM_IT_Update) != RESET)
{
TIM_ClearITPendingBit(TIM3, TIM_IT_Update);
// minimum high of 600 us for -90 degrees, with +90 degrees at 2400 us, 10 us per degree
// timer timebase set to us units to simplify the configuration/math
TIM3->CCR1 = 600 + ((servo_angle[0] + 90) * 10); // where angle is an int -90 to +90 degrees, PC.6
TIM3->CCR2 = 600 + ((servo_angle[1] + 90) * 10); // where angle is an int -90 to +90 degrees, PC.7
TIM3->CCR3 = 600 + ((servo_angle[2] + 90) * 10); // where angle is an int -90 to +90 degrees, PC.8
TIM3->CCR4 = 600 + ((servo_angle[3] + 90) * 10); // where angle is an int -90 to +90 degrees, PC.9
}
}
/**************************************************************************************/
int main(void)
{
RCC_Configuration();
GPIO_Configuration();
NVIC_Configuration();
TIM3_Configuration();
while(1)
{
// Insert code here to stroke your servos
}
}
/**************************************************************************************/
void RCC_Configuration(void)
{
// clock for GPIO and AFIO (Remap)
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOC | RCC_APB2Periph_AFIO, ENABLE);
// clock for TIM3
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM3, ENABLE);
}
/**************************************************************************************/
void NVIC_Configuration(void)
{
NVIC_InitTypeDef NVIC_InitStructure;
/* Configure the NVIC Preemption Priority Bits */
NVIC_PriorityGroupConfig(NVIC_PriorityGroup_0);
/* Enable the TIM3 Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM3_IRQn;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 2;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
}
/**************************************************************************************/
void GPIO_Configuration(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
// PC.06 TIM3_CH1
// PC.07 TIM3_CH2
// PC.08 TIM3_CH3
// PC.09 TIM3_CH4
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP;
GPIO_Init(GPIOC, &GPIO_InitStructure);
GPIO_PinRemapConfig(GPIO_FullRemap_TIM3, ENABLE); // Remap to get signal on PC.06-09
}
/**************************************************************************************/
void TIM3_Configuration(void)
{
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
TIM_OCInitTypeDef TIM_OCInitStructure;
// Simplify the math here so TIM_Pulse has 1 us units
// Use (24-1) for VL @ 24 MHz
// Use (72-1) for STM32 @ 72 MHz
TIM_TimeBaseStructure.TIM_Prescaler = 24 - 1; // 24 MHz / 24 = 1 MHz
TIM_TimeBaseStructure.TIM_Period = 20000 - 1; // 1 MHz / 20000 = 50 Hz (20 ms)
TIM_TimeBaseStructure.TIM_ClockDivision = TIM_CKD_DIV1;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM3, &TIM_TimeBaseStructure);
// Set up 4 channel servo
TIM_OCInitStructure.TIM_OCMode = TIM_OCMode_PWM1;
TIM_OCInitStructure.TIM_OutputState = TIM_OutputState_Enable;
TIM_OCInitStructure.TIM_Pulse = 600 + 900; // 1500 us - Servo Top Centre
TIM_OCInitStructure.TIM_OCPolarity = TIM_OCPolarity_High;
TIM_OC1Init(TIM3, &TIM_OCInitStructure); // Channel 1 configuration = PC.06 TIM3_CH1
TIM_OC2Init(TIM3, &TIM_OCInitStructure); // Channel 2 configuration = PC.07 TIM3_CH2
TIM_OC3Init(TIM3, &TIM_OCInitStructure); // Channel 3 configuration = PC.08 TIM3_CH3
TIM_OC4Init(TIM3, &TIM_OCInitStructure); // Channel 4 configuration = PC.09 TIM3_CH4
// turning on TIM3 and PWM outputs
TIM_Cmd(TIM3, ENABLE);
TIM_CtrlPWMOutputs(TIM3, ENABLE);
// TIM IT enable
TIM_ITConfig(TIM3, TIM_IT_Update, ENABLE);
}