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1. New construction
Second, select the chip model
The development board I use is the Punctual Atomic STM32F103ZET6 core board
3. Configure the clock
The development board is soldered with an external crystal, so I selected Crystal/Ceramic Resonator (quartz/ceramic resonator) for the RCC (Reset and Cock Control) configuration. After the configuration is complete, the relevant pins in the Pinout view on the right will be marked green.
After the external high-speed clock configuration is completed, enter the Clock Configuration option, according to the actual situation, configure the system clock to 72 MHz, the configuration steps are as follows, and finally press Enter, the software will automatically adjust the frequency division and frequency multiplication parameters.
Fourth, configure the debug mode
ST-Link is Serial Wire debug mode, be sure to set it! ! !
Before using the M0 chip, there was no problem without configuring this mode, but now this model, if the Serial Wire mode is not configured, once the program is programmed into the chip through ST-Link, the chip can no longer be recognized by ST-Link. (Later I returned to normal after burning the program/erasing through the STMISP tool)
Five, timer (PWM) parameter configuration
We choose channel 1 of the general-purpose timer TIM3 to output PWM. The specific parameters of PWM are configured as follows (turn on the PWM output of channel 1, pre-assign 72, PWM mode 1, and the duty cycle is temporarily 0)
The frequency division factor is 72-1, which means 72 frequency division (0 means 1 frequency division, 1 means 2 frequency division, and so on), the clock frequency of TIM3 is 72 MHz (see the following two figures). After dividing it by 72, the frequency becomes 1MHz, which is 1,000,000 counts per second. The period is set to 1000-1 (decrement by one here, it should be because the minimum count value is 0), which means that a complete PWM period is 1000 counts. Combined with the timer counting frequency, the PWM period is 1ms.
The default pin of TIM3_CH1 is PA6, you can also use PB4 or PC6,
I chose to replace the PWM output with PB4:
6. Generate Keil project
Set IDE and project directory and name:
Store the code of each peripheral in a different .c /.h file for easy management (otherwise it will be placed in main.c).
The following is the function code for TIM3 initialization and related GPIO configuration in the Keil project:
void MX_TIM3_Init(void)
{
/* USER CODE BEGIN TIM3_Init 0 */
/* USER CODE END TIM3_Init 0 */
TIM_ClockConfigTypeDef sClockSourceConfig = {
0};
TIM_MasterConfigTypeDef sMasterConfig = {
0};
TIM_OC_InitTypeDef sConfigOC = {
0};
/* USER CODE BEGIN TIM3_Init 1 */
/* USER CODE END TIM3_Init 1 */
htim3.Instance = TIM3;
htim3.Init.Prescaler = 72-1;
htim3.Init.CounterMode = TIM_COUNTERMODE_UP;
htim3.Init.Period = 1000-1;
htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim3.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
if (HAL_TIM_Base_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
if (HAL_TIM_PWM_Init(&htim3) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
sConfigOC.OCMode = TIM_OCMODE_PWM1;
sConfigOC.Pulse = 0;
sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
sConfigOC.OCFastMode = TIM_OCFAST_DISABLE;
if (HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
__HAL_TIM_DISABLE_OCxPRELOAD(&htim3, TIM_CHANNEL_1);
/* USER CODE BEGIN TIM3_Init 2 */
/* USER CODE END TIM3_Init 2 */
HAL_TIM_MspPostInit(&htim3);
}
void HAL_TIM_MspPostInit(TIM_HandleTypeDef* timHandle)
{
GPIO_InitTypeDef GPIO_InitStruct = {
0};
if(timHandle->Instance==TIM3)
{
/* USER CODE BEGIN TIM3_MspPostInit 0 */
/* USER CODE END TIM3_MspPostInit 0 */
__HAL_RCC_GPIOB_CLK_ENABLE();
/**TIM3 GPIO Configuration
PB4 ------> TIM3_CH1
*/
GPIO_InitStruct.Pin = GPIO_PIN_4;
GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
__HAL_AFIO_REMAP_TIM3_PARTIAL();
/* USER CODE BEGIN TIM3_MspPostInit 1 */
/* USER CODE END TIM3_MspPostInit 1 */
}
}
Seven, test example
The following is my test code (main.c), where the main function code is:
// 设置TIM3通道1的PWM的占空比
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_1, 500);
// 开启TIM3的通道1的PWM输出
HAL_TIM_PWM_Start(&htim3,TIM_CHANNEL_1);
main.c :
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2022 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "tim.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
extern TIM_HandleTypeDef htim3;
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */
/* USER CODE END PM */
/* Private variables ---------------------------------------------------------*/
/* USER CODE BEGIN PV */
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* USER CODE END 0 */
/**
* @brief The application entry point.
* @retval int
*/
int main(void)
{
/* USER CODE BEGIN 1 */
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
/* Reset of all peripherals, Initializes the Flash interface and the Systick. */
HAL_Init();
/* USER CODE BEGIN Init */
/* USER CODE END Init */
/* Configure the system clock */
SystemClock_Config();
/* USER CODE BEGIN SysInit */
/* USER CODE END SysInit */
/* Initialize all configured peripherals */
MX_GPIO_Init();
MX_TIM3_Init();
/* USER CODE BEGIN 2 */
// 设置TIM3通道1的PWM的占空比
__HAL_TIM_SET_COMPARE(&htim3, TIM_CHANNEL_1, 500);
// 开启TIM3的通道1的PWM输出
HAL_TIM_PWM_Start(&htim3,TIM_CHANNEL_1);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {
0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {
0};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
{
Error_Handler();
}
}
/* USER CODE BEGIN 4 */
/* USER CODE END 4 */
/**
* @brief This function is executed in case of error occurrence.
* @retval None
*/
void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
/* User can add his own implementation to report the HAL error return state */
__disable_irq();
while (1)
{
}
/* USER CODE END Error_Handler_Debug */
}
#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 CODE BEGIN 6 */
/* 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) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
Experimental effect:
PB4 outputs a PWM square wave with a period of 1ms and a duty cycle of 50%:
