STM32驱动全彩LED灯模块WS2812

WS2812全彩LED灯模块系列，可以进行级联实现灯带的效果，MCU端通过一个管脚可以控制所有级联的LED灯的不同发光颜色显示。
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级联电路

WS2811(未集成LED）的级联电路如下所示：
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WS2812（集成LED）的级联电路如下所示：

STM32是3.3V供电芯片，输出Push-Pull模式只有3.3V，WS2812采用5V供电，输入Vih为0.7*5=3.5V高于3.3V，所以STM32连接WS2812时要采用有FT耐5V电压的管脚，采用Open-drain的输出方式，并外部上拉1K电阻，实现与第一个WS2812的DI的连接，对于后面级联的WS2812，由前一级DO驱动5V信号输出，直接DO连接DI即可。
实现STM32驱动控制WS282的时序信号，由于时序输出翻转延迟达到了百纳秒级，需要硬件资源驱动的管脚输出，可以用SPI总线的MOSI实现。因为MCU的SPI总线资源较少，定时器资源相对较多，因此这里介绍采用TIM PWM方式的驱动实现。
以STM32F103C6T6为例，选择同时具有FT和TIM PWM输出特性的管脚，这里选择PB10:
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连接关系简图：

时序说明

驱动器（STM32)输出RESET指示信号（>280us, 低电平有效）, 此信号为双目的，一则WS2812的DI输入识别到有大于280us的低电平信号, 则将之前配置的数据驱动输出给三色/三个LED。二则进入到等待状态，等待下一次的数据配置信号到来。
数据配置信号为24个位一组，对应R, G, B三色各256级深度，即R, G, B各用一个字节/8位表示，如下所示：

注意24位对应3个字节并非是R, G, B顺序输出，而是G, R, B顺序输出，每个字节是高位在前进行发送。
每个位的发送时序都是由高低电平组成，由高电平和低电平的相对时长判断该位是0还是1：

高电平和低电平有时长范围要求：

可以看出主要先规划短电平时长和宽电平时长，这里基于STM32F103的72MHz，可以在TIM分频出对应125ns的计数周期，所以选择短电平时长为1253 = 375ns，选择短电平时长为12512 = 1.5us，后面进行工程配置和代码编写。

STM32工程配置

这里以STM32CUBEIDE开发平台对STM32F103C6T6芯片进行配置为例，首先建立基本工程并配置时钟主频为72MHz：
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然后配置PB10为TIM PWM输出的Open-drain模式：

配置TIM时钟为8MHz，并配置PWM的参数：

这里需要注意，Output compare preload需要配置为Enable, 因为后面的时序逻辑里，会在当前周期的PWM输出时修改PWM输出的占空比，而这个占空比修改的施行是在下一个周期，并不再当前周期。
保存并产生基本工程代码：
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STM32工程代码

驱动逻辑的实现主要是通过启动TIM PWM输出时，在不同的时刻控制PWM输出的占空比，如RESET指示信号的输出即为控制输出占空比为0，而逻辑1和逻辑0信号的输出则是在每个逻辑输出前调整PWM占空比以对应逻辑1和逻辑0。

代码里用到的纳秒级延时介绍：
STM32 纳秒级延时 (ns delay) 的指令延时实现方式及测定
代码里用到的半微秒级延时介绍：
STM32 HAL us delay（微秒延时）的指令延时实现方式及优化

代码实现单个LED模块驱动，需要驱动多个LED模块, 进行驱动函数扩展即可。完整的代码如下：

/* 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"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
__IO float semiusDelayBase;
void PY_semiusDelayTest(void)
{
__IO uint32_t firstms, secondms;
__IO uint32_t counter = 0;

  firstms = HAL_GetTick()+1;
  secondms = firstms+1;

  while(uwTick!=firstms) ;

  while(uwTick!=secondms) counter++;

  semiusDelayBase = ((float)counter)/2000;
}

void PY_Delay_semius_t(uint32_t Delay)
{
__IO  uint32_t delayReg;
__IO  uint32_t semiusNum = (uint32_t)(Delay*semiusDelayBase);

  delayReg = 0;
  while(delayReg!=semiusNum) delayReg++;
}

void PY_semiusDelayOptimize(void)
{
__IO  uint32_t firstms, secondms;
__IO  float coe = 1.0;

  firstms = HAL_GetTick();
  PY_Delay_semius_t(2000000) ;
  secondms = HAL_GetTick();

  coe = ((float)1000)/(secondms-firstms);
  semiusDelayBase = coe*semiusDelayBase;
}

void PY_Delay_semius(uint32_t Delay)
{
__IO  uint32_t delayReg;

  uint32_t msNum = Delay/2000;
  uint32_t semiusNum = (uint32_t)((Delay%2000)*semiusDelayBase);

  if(msNum>0) HAL_Delay(msNum);

  delayReg = 0;
  while(delayReg!=semiusNum) delayReg++;
}
/* 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 ---------------------------------------------------------*/
TIM_HandleTypeDef htim2;

/* USER CODE BEGIN PV */
#define TX_0 __HAL_TIM_SetCompare(&htim2, TIM_CHANNEL_3, 3)
#define TX_1 __HAL_TIM_SetCompare(&htim2, TIM_CHANNEL_3, 12)
#define TX_RST __HAL_TIM_SetCompare(&htim2, TIM_CHANNEL_3, 0)

void PY_RGB_TX_Init(void)
{
	__HAL_TIM_SetCounter(&htim2, 0);
	TX_RST;
	HAL_TIM_PWM_Start(&htim2,TIM_CHANNEL_3);
	PY_Delay_semius_t(600);
}

#define timing_delay {ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;ns_delay >>= 1;}
void PY_RGB_TX_24bits(uint8_t R, uint8_t G, uint8_t B) //Written by Pegasus Yu in 2022
{ //Data transmit in order of GRB, high bit data at first
	uint32_t ns_delay = 0x55555555;

	 __HAL_TIM_SetCounter(&htim2, 0);

	if((G<<0)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<1)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<2)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<3)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<4)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<5)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<6)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((G<<7)&0x80) TX_1;
	else TX_0;

	timing_delay
	if((R<<0)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<1)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<2)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<3)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<4)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<5)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<6)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((R<<7)&0x80) TX_1;
	else TX_0;

	timing_delay
	if((B<<0)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<1)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<2)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<3)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<4)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<5)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<6)&0x80) TX_1;
	else TX_0;
	timing_delay
	if((B<<7)&0x80) TX_1;
	else TX_0;


	PY_Delay_semius_t(1);
	TX_RST;
	PY_Delay_semius_t(600);

}
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_TIM2_Init(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_TIM2_Init();
  /* USER CODE BEGIN 2 */
  PY_semiusDelayTest();
  PY_semiusDelayOptimize();

  PY_RGB_TX_Init();



  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
	  PY_RGB_TX_24bits(255, 0, 0);
	  PY_Delay_semius_t(4000000);

	  PY_RGB_TX_24bits(0, 255, 0);
	  PY_Delay_semius_t(4000000);

	  PY_RGB_TX_24bits(0, 0, 255);
	  PY_Delay_semius_t(4000000);

	  PY_RGB_TX_24bits(127, 0, 127);
	  PY_Delay_semius_t(4000000);


    /* 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();
  }
}

/**
  * @brief TIM2 Initialization Function
  * @param None
  * @retval None
  */
static void MX_TIM2_Init(void)
{

  /* USER CODE BEGIN TIM2_Init 0 */

  /* USER CODE END TIM2_Init 0 */

  TIM_ClockConfigTypeDef sClockSourceConfig = {0};
  TIM_MasterConfigTypeDef sMasterConfig = {0};
  TIM_OC_InitTypeDef sConfigOC = {0};

  /* USER CODE BEGIN TIM2_Init 1 */

  /* USER CODE END TIM2_Init 1 */
  htim2.Instance = TIM2;
  htim2.Init.Prescaler = 8;
  htim2.Init.CounterMode = TIM_COUNTERMODE_UP;
  htim2.Init.Period = 14;
  htim2.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
  htim2.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
  if (HAL_TIM_Base_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
  if (HAL_TIM_ConfigClockSource(&htim2, &sClockSourceConfig) != HAL_OK)
  {
    Error_Handler();
  }
  if (HAL_TIM_PWM_Init(&htim2) != HAL_OK)
  {
    Error_Handler();
  }
  sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET;
  sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
  if (HAL_TIMEx_MasterConfigSynchronization(&htim2, &sMasterConfig) != HAL_OK)
  {
    Error_Handler();
  }
  sConfigOC.OCMode = TIM_OCMODE_PWM1;
  sConfigOC.Pulse = 3;
  sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH;
  sConfigOC.OCFastMode = TIM_OCFAST_ENABLE;
  if (HAL_TIM_PWM_ConfigChannel(&htim2, &sConfigOC, TIM_CHANNEL_3) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN TIM2_Init 2 */

  /* USER CODE END TIM2_Init 2 */
  HAL_TIM_MspPostInit(&htim2);

}

/**
  * @brief GPIO Initialization Function
  * @param None
  * @retval None
  */
static void MX_GPIO_Init(void)
{

  /* GPIO Ports Clock Enable */
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

}

/* 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 */