This post was last edited by eew_cT3H5d on 2024-7-23 23:58
First look at the effect:
WS2812B-5050 is an intelligent externally controlled LED light source that integrates control circuit and light-emitting circuit. Its appearance adopts the latest molding packaging technology, and the IC and light-emitting chip are packaged in a 5050 package size. Each component is a pixel. The pixel contains an intelligent digital interface data latch signal shaping and amplification drive circuit, a high-precision internal oscillator and a programmable constant current control part, which effectively ensures that the color of the pixel light is highly consistent.
It can display the color display light composed of the three primary colors of RGB. It is packaged as 5050 and has four pins, namely VCC, VSS, DIN, and DOUT. Its control protocol is very simple, and serial asynchronous signal transmission can be performed through a signal line
The cascade control protocol of WS2812 is very simple. Different high and low level pulses are used in serial communication to represent data 0,1 encoding. By sending three groups of 24-bit encoding, the colors of three cascaded WS2812 lights can be controlled. The GRB encoding corresponding to each group of 24 bits is shown below. The color sending order is GRB, with the high bit of the byte first.
The WS2812 driver chip uses a single-line return-to-zero code communication method. After the chip is powered on and reset, the DIN terminal receives the data transmitted from the controller. The first 24-bit data is extracted by the first chip and sent to the data latch inside the chip. The remaining data is shaped and amplified by the internal shaping processing circuit, and then forwarded to the next cascade chip through the DO port. After each chip is transmitted, the signal is reduced by 24 bits. The chip uses automatic shaping and forwarding technology, so that the number of cascades of the chip is not limited by signal transmission, but only by the signal transmission speed requirement.
Drive waveform logic analyzer test:
Logic analyzer waveform display:
Renesas RA8D1 controls ws2812 via SPI bus
Step 1: Continue to add SPI driver module in the previous project
Configure the SPI channel. By configuring channel 3, you can directly connect the SPI pins P309, P311, and P310 to the ws2812 directly through the lead pins of the development board.
After querying, the configuration speed of SPI is set to 7.5M, and the related clock can be 60Mhz or 120Mhz
Configure the system clock, use the internal clock, and configure the related clock to 120Mhz
Step 2: Add ws2812 underlying driver library
ws2812.c file
/*
* ws2812.c
*
* Created on: 2023年10月31日
* Author: Administrator
*/
#include <WS2812/ws2812.h>
#include "hal_data.h"
extern fsp_err_t err ;
extern volatile bool g_transfer_complete ;
//灯条显存SPI数据缓存
uint8_t gWs2812bDat_SPI[WS2812B_AMOUNT * 24+88] = {0};
//灯条显存
tWs2812bCache_TypeDef gWs2812bDat[WS2812B_AMOUNT] = {
//R G B
0XFF, 0X00, 0X00, //0
0X00, 0XFF, 0X00, //1
0X00, 0X00, 0XFF, //2
0X00, 0XFF, 0XFF, //3
0XFF, 0X00, 0XFF, //4
0XFF, 0XFF, 0X00, //5
0XFF, 0XFF, 0XFF, //6
0X00, 0X00, 0X00, //7
};
void WS2812b_Set(uint16_t Ws2b812b_NUM, uint8_t r,uint8_t g,uint8_t b)
{
uint8_t *pR = &gWs2812bDat_SPI[88+(Ws2b812b_NUM) * 24 + 8];
uint8_t *pG = &gWs2812bDat_SPI[88+(Ws2b812b_NUM) * 24];
uint8_t *pB = &gWs2812bDat_SPI[88+(Ws2b812b_NUM) * 24 + 16];
for(uint8_t i = 0; i < 8; i++) {
if(g & 0x80) {
*pG = CODE_1;
}
else {
*pG = CODE_0;
}
if(r & 0x80) {
*pR = CODE_1;
}
else {
*pR = CODE_0;
}
if(b & 0x80) {
*pB = CODE_1;
}
else {
*pB = CODE_0;
}
r <<= 1;
g <<= 1;
b <<= 1;
pR++;
pG++;
pB++;
}
}
void WS2812B_Task(void)
{
uint8_t dat = 0;
for(int i=0;i<88;i++)
{
gWs2812bDat_SPI[i]=0;
}
//将gWs2812bDat数据解析成SPI数据
for(uint8_t iLED = 0; iLED < WS2812B_AMOUNT; iLED++)
{
WS2812b_Set(iLED, gWs2812bDat[iLED].R, gWs2812bDat[iLED].G, gWs2812bDat[iLED].B);
}
//总线输出数据
/* Send the reset command */
g_transfer_complete = false;
err = R_SCI_B_SPI_Write(&g_sci_spi3_ctrl, gWs2812bDat_SPI, sizeof(gWs2812bDat_SPI), SPI_BIT_WIDTH_8_BITS);
assert(FSP_SUCCESS == err);
/* Wait for SPI_EVENT_TRANSFER_COMPLETE callback event. */
while ( g_transfer_complete==false)
{
;
}
// //使总线输出低电平
// g_transfer_complete = false;
// err = R_SCI_SPI_Write(&g_spi0_ctrl, dat, 1, SPI_BIT_WIDTH_8_BITS);
// assert(FSP_SUCCESS == err);
// /* Wait for SPI_EVENT_TRANSFER_COMPLETE callback event. */
// while ( g_transfer_complete==false)
// {
// ;
// }
//帧信号：一个大于50us的低电平
R_BSP_SoftwareDelay(1, BSP_DELAY_UNITS_MILLISECONDS);
}
ws2812.h file
/*
* ws2812.h
*
* Created on: 2023年10月31日
* Author: Administrator
*/
#ifndef _WS2812_H_
#define _WS2812_H_
#include <stdint.h>
// 编码 0 : 11000000
#define CODE_0 0xc0
// 编码 1 : 11111000
#define CODE_1 0xF8
/*ws2812b灯珠数量*/
#define WS2812B_AMOUNT 8
typedef struct
{
uint8_t R;
uint8_t G;
uint8_t B;
} tWs2812bCache_TypeDef;
extern tWs2812bCache_TypeDef gWs2812bDat[WS2812B_AMOUNT];
void WS2812b_Set(uint16_t Ws2b812b_NUM, uint8_t r,uint8_t g,uint8_t b);
void WS2812B_Task(void);
#endif /* WS2812_H_ */
This is the main program running code, which allows ws2812 to display different colors
Step 3: Compile the program
Step 4: Program running effect: Successfully light up the ws2812 full-color LED, SPI drive is successful at one time
Video Demonstration:
ws2812
References:
1.https://blog.csdn.net/qq_24312945/article/details/134152211
2.https://en.eeworld.com/bbs/thread-1267092-1-1.html
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