STM32 Discovery, RC Receiver, PWM Input

[benjamin-chia]

Posted on February 11, 2014 at 08:10

Hi Clive,

Thank you so much for the code. I added parts of it to the PWM input code and it works great! I am however only able to get a reading from one channel at the moment. I was hoping to use all 4 channels from TIM 4. Could you please advise me on this. Do you work for STM? You seem to reply to every message in this forum! Thanks for your help!!

/*
* futaba.c
*
* Created on: 3 Feb 2014
* Author: Benjamin
*/
#include ''stm32f4xx.h''
#include ''stm32f4xx_rcc.h''
#include ''stm32f4xx_gpio.h''
#include ''stm32f4xx_tim.h''
#include ''stm32f4xx_syscfg.h''
#include ''stm32f4xx_exti.h''
#include ''misc.h''
/**
******************************************************************************
* @file TIM/TIM_PWMInput/main.c
* @author MCD Application Team
* @version V1.2.0
* @date 19-September-2013
* @brief Main program body
******************************************************************************
* @attention
*
* <
h2
><
center
>© COPYRIGHT 2013 STMicroelectronics</
center
></
h2
>
*
* Licensed under MCD-ST Liberty SW License Agreement V2, (the ''License'');
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at:
*
* http://www.st.com/software_license_agreement_liberty_v2
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an ''AS IS'' BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
******************************************************************************
*/
/* Includes ------------------------------------------------------------------*/
#include ''stm32f4xx.h''
#include ''stm32f4xx_gpio.h''
#include ''stm32f4xx_rcc.h''
#include ''stm32f4xx_tim.h''
#include ''stm32f4xx_syscfg.h''
#include ''stm32f4xx_exti.h''
#include ''misc.h''
/** @addtogroup STM32F4xx_StdPeriph_Examples
* @{
*/
/** @addtogroup TIM_PWMInput
* @{
*/
/* Private typedef -----------------------------------------------------------*/
/* Private define ------------------------------------------------------------*/
/* Private macro -------------------------------------------------------------*/
/* Private variables ---------------------------------------------------------*/
TIM_ICInitTypeDef TIM_ICInitStructure;
/* Private function prototypes -----------------------------------------------*/
void TIM_Config(void);
int ch1, ch2, ch3, ch4;
/* Private functions ---------------------------------------------------------*/
/**
* @brief Main program
* @param None
* @retval None
*/
int initfutaba(void)
{
TIM_Config();
/*!< 
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();
/* ---------------------------------------------------------------------------
TIM4 configuration: PWM Input mode
In this example TIM4 input clock (TIM4CLK) is set to 2 * APB1 clock (PCLK1),
since APB1 prescaler is different from 1.
TIM4CLK
= 
2
* PCLK1
PCLK1
= 
HCLK
/ 4
=> TIM4CLK = HCLK / 2 = SystemCoreClock /2
External Signal Frequency = TIM4 counter clock / TIM4_CCR2 in Hz.
External Signal DutyCycle = (TIM4_CCR1*100)/(TIM4_CCR2) in %.
--------------------------------------------------------------------------- */
TIM_ICInitStructure.TIM_ICPolarity = TIM_ICPolarity_Rising;
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
TIM_ICInitStructure.TIM_ICPrescaler = TIM_ICPSC_DIV1;
TIM_ICInitStructure.TIM_ICFilter = 0x0;
TIM_ICInitStructure.TIM_Channel = TIM_Channel_1;
TIM_PWMIConfig(TIM4, &TIM_ICInitStructure);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_2;
TIM_PWMIConfig(TIM4, &TIM_ICInitStructure);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_3;
TIM_PWMIConfig(TIM4, &TIM_ICInitStructure);
TIM_ICInitStructure.TIM_Channel = TIM_Channel_4;
TIM_PWMIConfig(TIM4, &TIM_ICInitStructure);
/* Select the TIM4 Input Trigger: TI2FP2 */
TIM_SelectInputTrigger(TIM4, TIM_TS_TI2FP2);
/* Select the slave Mode: Reset Mode */
TIM_SelectSlaveMode(TIM4, TIM_SlaveMode_Reset);
TIM_SelectMasterSlaveMode(TIM4,TIM_MasterSlaveMode_Enable);
/* TIM enable counter */
TIM_Cmd(TIM4, ENABLE);
/* Enable the CC2 Interrupt Request */
TIM_ITConfig(TIM4, TIM_IT_CC1, ENABLE);
TIM_ITConfig(TIM4, TIM_IT_CC2, ENABLE);
TIM_ITConfig(TIM4, TIM_IT_CC3, ENABLE);
TIM_ITConfig(TIM4, TIM_IT_CC4, ENABLE);
// ch1 = TIM_GetCapture1(TIM4);
// while (1);
return 0;
}
int futaba(void)
{
return 0;
}
/**
* @brief Configure the TIM4 Pins.
* @param None
* @retval None
*/
void TIM_Config(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
NVIC_InitTypeDef NVIC_InitStructure;
TIM_TimeBaseInitTypeDef TIM_TimeBaseStructure;
/* TIM4 clock enable */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_TIM4, ENABLE);
/* GPIOB clock enable */
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);
/* TIM4 chennel2 configuration : PB.07 */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8| GPIO_Pin_9 ;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;
GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP ;
GPIO_Init(GPIOB, &GPIO_InitStructure);
/* Connect TIM pin to AF2 */
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_TIM4);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource7, GPIO_AF_TIM4);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource8, GPIO_AF_TIM4);
GPIO_PinAFConfig(GPIOB, GPIO_PinSource9, GPIO_AF_TIM4);
/* Enable the TIM4 global Interrupt */
NVIC_InitStructure.NVIC_IRQChannel = TIM4_IRQn;
NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
NVIC_InitStructure.NVIC_IRQChannelSubPriority = 1;
NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
NVIC_Init(&NVIC_InitStructure);
/* Time base configuration - SystemCoreClock = 168000000 for 168 MHz board ABP1 @ 42 MHz (DIV4) */
TIM_TimeBaseStructure.TIM_Prescaler = (uint16_t) (((SystemCoreClock / 1000000) / 2) - 1); // Shooting for 1 MHz, (1us)
TIM_TimeBaseStructure.TIM_Period = 0xFFFF; // Maximal
TIM_TimeBaseStructure.TIM_ClockDivision = 0;
TIM_TimeBaseStructure.TIM_CounterMode = TIM_CounterMode_Up;
TIM_TimeBaseInit(TIM4, &TIM_TimeBaseStructure);
}
void TIM4_IRQHandler(void)
{
if (TIM_GetITStatus(TIM4, TIM_IT_CC1) != RESET)
{
TIM_ClearITPendingBit(TIM4, TIM_IT_CC1);
ch1 = TIM_GetCapture1(TIM4);
}
if (TIM_GetITStatus(TIM4, TIM_IT_CC2) != RESET)
{
TIM_ClearITPendingBit(TIM4, TIM_IT_CC2);
ch2 = TIM_GetCapture2(TIM4);
}
if (TIM_GetITStatus(TIM4, TIM_IT_CC3) != RESET)
{
TIM_ClearITPendingBit(TIM4, TIM_IT_CC3);
ch3 = TIM_GetCapture3(TIM4); // Period (us) ~20000
}
if (TIM_GetITStatus(TIM4, TIM_IT_CC4) != RESET)
{
TIM_ClearITPendingBit(TIM4, TIM_IT_CC4);
ch4 = TIM_GetCapture4(TIM4); // Period (us) ~20000
}
}
#ifdef USE_FULL_ASSERT
/**
* @brief Reports the name of the source file and the source line number
* where the assert_param error has occurred.
* @param file: pointer to the source file name
* @param line: assert_param error line source number
* @retval None
*/
void assert_failed(uint8_t* file, uint32_t line)
{
/* User can add his own implementation to report the file name and line number,
ex: printf(''Wrong parameters value: file %s on line %d\r\n'', file, line) */
while (1)
{}
}
#endif
/**
* @}
*/
/**
* @}
*/
/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/