Ws2812b color lamp driver based on f407zgt6

Hardware connection

WS2812B It's a full color LED control IC, Single bus control , You can cascade .

Single lamp bead connection will DIN The foot is connected to a IO Port and connect the power supply
A plurality of lamp beads are connected in series to connect the first lamp bead DOUT The foot is connected to the next lamp bead DIN foot

Driving principle

1. Sequence diagram

Pictured , Represented by different durations of high and low levels 0 perhaps 1, Use a long period of time to pull down to show reset, The following figure shows the corresponding different duration .

2. Data transmission mode

Pictured ,MCU To be connected in series GRB The code is transmitted into the first light bead , Each lamp receives 24bit data （GRB Color value ）,D1 The light is receiving 24bit After the data , Will save the data , If you still receive data , Will pass DO Pass the foot to D2.

a key ： The time of high and low levels must be controlled within the requirements of the specification

Driver code

Code part reference _ Xiangzi @ This elder brother's article

WS2812.h

typedef struct color{
    				// Structure definition 
  
  uint8_t R;
  uint8_t G;
  uint8_t B;
  
}Color_TypeDef;

#define LED_NUM 12 // Define the number of light beads , Easy to modify 
#define WS2812B_High() HAL_GPIO_WritePin(RGB_GPIO_Port,RGB_Pin,GPIO_PIN_SET); // Define higher and lower 
#define WS2812B_Low() HAL_GPIO_WritePin(RGB_GPIO_Port,RGB_Pin,GPIO_PIN_RESET);

/******************************************* function *********************************************/
void delay_320ns(void);
void delay_1000ns(void);
void MY_delay_us(uint16_t num);

void WS2812B_Reset(void);
void WS2812B_WriteByte(uint8_t dat);
void WS2812B_WriteColor(Color_TypeDef *pColor);

void Copy_Color(Color_TypeDef *pDst,Color_TypeDef *pScr);
void WS2812B_Refresh(void);
void WS2812B_Fillcolor(uint16_t start,uint16_t end,Color_TypeDef *pColor);
void WS2812B_Move(uint8_t dir);

WS2812.c

1. First write send 0 code 1 The function of the code , Used __nop(); function , One __nop() Corresponding to a machine cycle , The specific duration needs to be measured

void delay_320ns(void)    //T0H & T1L  Time delay 320ns
{
    
  uint8_t i;
  for(i=0;i<5;i++)
  {
    
  __nop();
  }
}

void delay_1000ns(void) //T0L & T1H // Time delay 1000ns
{
    
  uint8_t i;
  for(i=0;i<25;i++)
  {
    
  __nop();
  }
}

void MY_delay_us(uint16_t num)			//us Stage delay 
{
    
  uint8_t i;
  while(num)
  {
    
    for(i=0;i<25;i++)
    {
    
    __nop();
    }
    num--;
  }
}

How to measure the time delay & function
stay main This function is called in the function , Then open debug, Test the delay duration of two functions in turn , Keep changing the number of cycles until the duration meets the timing requirements .

void WS2812B_Test2(void)
{
    
	WS2812B_Hi();
	delay_320ns();
	//delay_1000ns();
	WS2812B_Low();
}

debug The test method
Add breakpoints before and after the test function and place them in while Inside , Get into debug Look back at the lower right corner

If it is t0 Right click to select t2 perhaps t1.
When the breakpoint in front of the test function stops, right-click to clear the value , The value displayed when the breakpoint to the end stops is the actual time of the delay function

2. Write data sending function

void WS2812B_Reset(void)					//reset function 
{
    
  WS2812B_Low();
  int i=60;
	while(i--)
	{
    
		delay_1000ns();
	}
}

void WS2812B_WriteByte(uint8_t dat)				// Write a byte 
{
    
	uint8_t i;
	for (i=0;i<8;i++)
	{
    
		// Send the high bit first 
		if (dat & 0x80) //1 // data  &0x80 , If the high order is 1 The result is 1, Otherwise 0
		{
    
			WS2812B_High();
			delay_1000ns(); //T1H
			WS2812B_Low();	
			delay_320ns(); //T1L
		}
		else	//0
		{
    
			WS2812B_High();
			delay_320ns(); //T0H
			WS2812B_Low();	
			delay_1000ns(); //T0L
		}
		dat<<=1;
	}
}

void WS2812B_WriteColor(Color_TypeDef *pColor)		// Send color , Complete by sending bytes of three colors respectively 
{
    
    WS2812B_WriteByte(pColor->G);
	WS2812B_WriteByte(pColor->R);
	WS2812B_WriteByte(pColor->B);
} 

void WS2812B_Refresh(void)				// Refresh the latest structure data to the light display 
{
    
  uint8_t i;
  
  for(i=0;i<LED_NUM;i++)
  {
    
    WS2812B_WriteColor(&WS2812B_Buf[i]);
  }
}

3. Lamp bead color treatment
（ Realize the running lantern / Rainbow gradient ）

//1. Copy colors 
void Copy_Color(Color_TypeDef *pDst,Color_TypeDef *pScr)		// Give the color of the last lamp to the previous lamp bead 
{
    
  pDst->R = pScr->R;
	pDst->G = pScr->G;
	pDst->B = pScr->B;
}

//2. Fill color （ Used to give a long string of light beads the same color value ）
void WS2812B_Fillcolor(uint16_t start,uint16_t end,Color_TypeDef *pColor)		// Began in , finally , Color value 
{
    
  if(start>end)
  {
    
    uint16_t temp;
    temp=start;
    start=end;
    end=temp;
  }
  
  if (start>=LED_NUM)return;
  if(end>=LED_NUM)end=LED_NUM-1;
  
  while(start<=end)
  {
    
    Copy_Color(&WS2812B_Buf[start],pColor);
    start++;
  }
}

//3. Move the lamp bead color 
void WS2812B_Move(uint8_t dir)		//dir Is the number of moves , The bigger, the more 
{
    
  Color_TypeDef temp;
  uint8_t i;
  
  if(dir)
  {
    
    Copy_Color(&temp,&WS2812B_Buf[LED_NUM-1]);
    
    i = LED_NUM-1;
    while(i)
    {
    
      Copy_Color(&WS2812B_Buf[i],&WS2812B_Buf[i-1]);
      i--;
    }
    Copy_Color(&WS2812B_Buf[0],&temp);
  }
  else
  {
     
    Copy_Color(&temp,&WS2812B_Buf[0]);
    
    i = 0;
    while(i<(LED_NUM-1))
    {
    
      Copy_Color(&WS2812B_Buf[i],&WS2812B_Buf[i+1]);
      i++;
    }
    Copy_Color(&WS2812B_Buf[LED_NUM-1],&temp);
  }
}

main.c

Definition

Color_TypeDef WS2812B_Buf[LED_NUM];

initialization

  HAL_Init();
  SystemClock_Config();
  MX_GPIO_Init();

  uint8_t i;
  for(i=0;i<8;i++)								// Before giving 12 The two light beads are different GRB value , What's given here is R-G-B The gradient 
  {
    
    WS2812B_Buf[i].R=63-7*i;
    WS2812B_Buf[i].G=7*i;
    WS2812B_Buf[i].B=0;
    HAL_Delay(1);
  }
    for(i=8;i<12;i++)
  {
    
    
    WS2812B_Buf[i].R=0;
    WS2812B_Buf[i].G=127-7*i;
    WS2812B_Buf[i].B=7*i-56;
    HAL_Delay(1);
  }
  
  WS2812B_Refresh();	// Because the previous step only updated the color value , It doesn't show , So join refresh Refresh the display 

loop

while(1)
{
    
	HAL_Delay(40);			// The time delay is used to adjust the speed 
    WS2812B_Move(5);		//move Function controls the number of moves 
    WS2812B_Refresh();		// Refresh the display 
}

Effect display

Initialized light effect （ Add a uniform board or painted acrylic board to make the light more uniform ）
（ Casually picked up a piece of paint sprayed on the waste board ）