ws2812系列灯条，是一种可寻址的RGB LED彩灯，可以自定义颜色、点灯速度等。只需要一个IO就可以控制多个灯。ws2812系列有三根线，分别为VCC、GND、信号控制线。作为优化升级版的ws2813系列，更是具有断点续传功能，比如说有个灯坏了，但是它与后面的信号线没有断，信号可以正常传到后面去。
作为Arduino爱好者，这里推荐两个好用的库hastLed和Neopixel。
这里想和大家分享一下stm32连接ws2812~ 用的单片机是stm32f103zet6，这部分代码换成stm32f103c8t6照样跑的通。
一、添加ws2812.c和ws2812.h文件
直接使用正点原子模板向HARDWARE文件夹下，新建一个文件夹命名为ws2812，然后新建ws2812.c和ws2812.h。
然后把一下文件分别复制到对应c和h文件
1、ws2812.h
#ifndef __WS2812_H
#define __WS2812_H
#include "stm32f10x.h"
#define PIXEL_NUM 60
//硬件spi模拟ws2811时序（用spi的8位数据模拟ws281x的一位数据）
//要将系统时钟设置为56M，分频数设置为8，则SPI的通信频率为7M，传输一位数据的时间约为143纳秒（ns）
//3*143 = 429ns 5*143 = 715ns 符合WS281X芯片的通信时序。
// _____
// | |___| 11111000 high level
// ___
// | |_____| 11100000 low level
#define WS_HIGH 0XF8
#define WS_LOW 0XE0
void ws281x_init(void);
void ws281x_closeAll(void);
void ws281x_rainbowCycle(uint8_t wait);
uint32_t ws281x_color(uint8_t red, uint8_t green, uint8_t blue);
void ws281x_setPixelColor(uint16_t n ,uint32_t GRBcolor);
void ws281x_show(void);
void ws281x_theaterChase(uint32_t c, uint8_t wait);
void ws281x_colorWipe(uint32_t c, uint8_t wait);
void ws281x_rainbow(uint8_t wait);
void ws281x_theaterChaseRainbow(uint8_t wait);
#endif /* __WS2812_H */
2、ws2812.c
#include "ws2812.h"
#include "usart.h"
#include "delay.h"
uint8_t pixelBuffer[PIXEL_NUM][24] ;
void ws281x_init(void)
{
GPIO_InitTypeDef GPIO_InitStructure;
SPI_InitTypeDef SPI_InitStructure;
DMA_InitTypeDef DMA_InitStructure;
RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOA, ENABLE); //PORTA时钟使能
RCC_APB2PeriphClockCmd(RCC_APB2Periph_SPI1, ENABLE); //SPI1时钟使能
RCC_AHBPeriphClockCmd(RCC_AHBPeriph_DMA1, ENABLE); //使能DMA传输
/* PA7 SPI1_MOSI */
GPIO_InitStructure.GPIO_Pin = GPIO_Pin_7;
GPIO_InitStructure.GPIO_Mode = GPIO_Mode_AF_PP; //PA7复用推挽输出 SPI
GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz;
GPIO_Init(GPIOA, &GPIO_InitStructure);//初始化GPIOA
SPI_InitStructure.SPI_Direction = SPI_Direction_1Line_Tx; //设置SPI单向或者双向的数据模式:SPI设置为双线双向全双工
SPI_InitStructure.SPI_Mode = SPI_Mode_Master; //设置SPI工作模式:设置为主SPI
SPI_InitStructure.SPI_DataSize = SPI_DataSize_8b; //设置SPI的数据大小:SPI发送接收8位帧结构
SPI_InitStructure.SPI_CPOL = SPI_CPOL_Low; //串行同步时钟的空闲状态为低电平
SPI_InitStructure.SPI_CPHA = SPI_CPHA_2Edge; //串行同步时钟的第2个跳变沿（上升或下降）数据被采样
SPI_InitStructure.SPI_NSS = SPI_NSS_Soft; //NSS信号由硬件（NSS管脚）还是软件（使用SSI位）管理:内部NSS信号有SSI位控制
SPI_InitStructure.SPI_BaudRatePrescaler = SPI_BaudRatePrescaler_8; //定义波特率预分频的值:波特率预分频值为16
SPI_InitStructure.SPI_FirstBit = SPI_FirstBit_MSB; //指定数据传输从MSB位还是LSB位开始:数据传输从MSB位开始
SPI_InitStructure.SPI_CRCPolynomial = 7; //CRC值计算的多项式
SPI_Init(SPI1, &SPI_InitStructure); //根据SPI_InitStruct中指定的参数初始化外设SPIx寄存器
SPI_Cmd(SPI1, ENABLE); //使能SPI外设
SPI_I2S_DMACmd(SPI1, SPI_I2S_DMAReq_Tx, ENABLE);
DMA_DeInit(DMA1_Channel3); //将DMA的通道1寄存器重设为缺省值
DMA_InitStructure.DMA_PeripheralBaseAddr = (uint32_t) &(SPI1 -> DR); //cpar; //DMA外设ADC基地址
DMA_InitStructure.DMA_MemoryBaseAddr = (uint32_t)pixelBuffer; //cmar; //DMA内存基地址
DMA_InitStructure.DMA_DIR = DMA_DIR_PeripheralDST; //数据传输方向，从内存读取发送到外设
DMA_InitStructure.DMA_BufferSize = PIXEL_NUM * 24; //cndtr; //DMA通道的DMA缓存的大小
DMA_InitStructure.DMA_PeripheralInc = DMA_PeripheralInc_Disable; //外设地址寄存器不变
DMA_InitStructure.DMA_MemoryInc = DMA_MemoryInc_Enable; //内存地址寄存器递增
DMA_InitStructure.DMA_PeripheralDataSize = DMA_PeripheralDataSize_Byte; //数据宽度为8位
DMA_InitStructure.DMA_MemoryDataSize = DMA_MemoryDataSize_Byte; //数据宽度为8位
DMA_InitStructure.DMA_Mode = DMA_Mode_Normal; //工作在正常缓存模式
DMA_InitStructure.DMA_Priority = DMA_Priority_Medium; //DMA通道 x拥有中优先级
DMA_InitStructure.DMA_M2M = DMA_M2M_Disable; //DMA通道x没有设置为内存到内存传输
DMA_Init(DMA1_Channel3, &DMA_InitStructure); //根据DMA_InitStruct中指定的参数初始化DMA的通道USART1_Tx_DMA_Channel所标识的寄存器
ws281x_closeAll(); //关闭全部的灯
delay_ms(100); //关闭全部的灯需要一定的时间
}
void ws281x_closeAll(void)
{
uint16_t i;
uint8_t j;
for(i = 0; i < PIXEL_NUM; ++i)
{
for(j = 0; j < 24; ++j)
{
pixelBuffer[i][j] = WS_LOW;
}
}
ws281x_show();
}
uint32_t ws281x_color(uint8_t red, uint8_t green, uint8_t blue)
{
return green << 16 | red << 8 | blue;
}
void ws281x_setPixelColor(uint16_t n ,uint32_t GRBcolor)
{
uint8_t i;
if(n < PIXEL_NUM)
{
for(i = 0; i < 24; ++i)
{
pixelBuffer[n][i] = (((GRBcolor << i) & 0X800000) ? WS_HIGH : WS_LOW);
}
}
}
void ws281x_setPixelRGB(uint16_t n ,uint8_t red, uint8_t green, uint8_t blue)
{
uint8_t i;
if(n < PIXEL_NUM)
{
for(i = 0; i < 24; ++i)
{
pixelBuffer[n][i] = (((ws281x_color(red,green,blue) << i) & 0X800000) ? WS_HIGH : WS_LOW);
}
}
}
void ws281x_show(void)
{
DMA_Cmd(DMA1_Channel3, DISABLE ); //关闭USART1 TX DMA1 所指示的通道
DMA_ClearFlag(DMA1_FLAG_TC3);
DMA_SetCurrDataCounter(DMA1_Channel3,24 * PIXEL_NUM );//DMA通道的DMA缓存的大小
DMA_Cmd(DMA1_Channel3, ENABLE); //使能USART1 TX DMA1 所指示的通道
}
// Input a value 0 to 255 to get a color value.
// The colours are a transition r - g - b - back to r.
uint32_t ws281x_wheel(uint8_t wheelPos) {
wheelPos = 255 - wheelPos;
if(wheelPos < 85) {
return ws281x_color(255 - wheelPos * 3, 0, wheelPos * 3);
}
if(wheelPos < 170) {
wheelPos -= 85;
return ws281x_color(0, wheelPos * 3, 255 - wheelPos * 3);
}
wheelPos -= 170;
return ws281x_color(wheelPos * 3, 255 - wheelPos * 3, 0);
}
// Fill the dots one after the other with a color
void ws281x_colorWipe(uint32_t c, uint8_t wait) {
for(uint16_t i=0; i<PIXEL_NUM; i++) {
ws281x_setPixelColor(i, c);
ws281x_show();
delay_ms(wait);
}
}
void ws281x_rainbow(uint8_t wait) {
uint16_t i, j;
for(j=0; j<256; j++) {
for(i=0; i<PIXEL_NUM; i++) {
ws281x_setPixelColor(i, ws281x_wheel((i+j) & 255));
}
ws281x_show();
delay_ms(wait);
}
}
// Slightly different, this makes the rainbow equally distributed throughout
void ws281x_rainbowCycle(uint8_t wait) {
uint16_t i, j;
for(j=0; j<256*5; j++) { // 5 cycles of all colors on wheel
for(i=0; i< PIXEL_NUM; i++) {
ws281x_setPixelColor(i,ws281x_wheel(((i * 256 / PIXEL_NUM) + j) & 255));
}
ws281x_show();
delay_ms(wait);
}
}
//Theatre-style crawling lights.
void ws281x_theaterChase(uint32_t c, uint8_t wait) {
for (int j=0; j<10; j++) { //do 10 cycles of chasing
for (int q=0; q < 3; q++) {
for (uint16_t i=0; i < PIXEL_NUM; i=i+3) {
ws281x_setPixelColor(i+q, c); //turn every third pixel on
}
ws281x_show();
delay_ms(wait);
for (uint16_t i=0; i < PIXEL_NUM; i=i+3) {
ws281x_setPixelColor(i+q, 0); //turn every third pixel off
}
}
}
}
//Theatre-style crawling lights with rainbow effect
void ws281x_theaterChaseRainbow(uint8_t wait) {
for (int j=0; j < 256; j++) { // cycle all 256 colors in the wheel
for (int q=0; q < 3; q++) {
for (uint16_t i=0; i < PIXEL_NUM; i=i+3) {
ws281x_setPixelColor(i+q, ws281x_wheel( (i+j) % 255)); //turn every third pixel on
}
ws281x_show();
delay_ms(wait);
for (uint16_t i=0; i < PIXEL_NUM; i=i+3) {
ws281x_setPixelColor(i+q, 0); //turn every third pixel off
}
}
}
}
这两部简单地复制粘贴大家可以跟上的吧，接下来添加库到keil。
3、keil添加库
4、改mian.c代码
#include "led.h"
#include "delay.h"
#include "key.h"
#include "sys.h"
#include "usart.h"
#include "ws2812.h"
int8_t i;
void Delay(u32 count)
{
u32 i = 0;
for(; i < count; i++);
}
int main(void)
{
uart_init(115200);
delay_init();
ws281x_init();
while(1)
{
ws281x_colorWipe(ws281x_color(255, 0, 0), 50); // Red
ws281x_colorWipe(ws281x_color(0, 255, 0), 50); // Green
ws281x_colorWipe(ws281x_color(200, 255, 0), 50); //黄色
ws281x_colorWipe(ws281x_color(100, 255, 50), 50); //冰蓝
ws281x_colorWipe(ws281x_color(155, 255, 0), 50); //嫩绿色
}
}
复制完代码编译一下，这时候你会发现报错了！！！
不要方，这是由于我们没有添加stm32spi和dma文件。
添加进去，完美解决。鼓掌
上传代码到单片机，VCC、GND正常接，信号线接到PA7。
工程代码如下
qq-hh/qq-hh-My_Project_stm32 (github.com)
ws2812+stm32视频