如何使用SPI接口驱动WS2812B

#include <stdio.h>

#include "NuMicro.h"



#define SPI_CLK_FREQ    2500000

#define LED_NUMBER 10



void SYS_Init(void);

void SPI_Init(void);

unsigned int data_bit8_to_bit24(uint8_t data);

void send_led_commands(uint8_t Led_number, uint8_t G,uint8_t R,uint8_t B);





void send_array_clear(void){

uint8_t led_counter=0;



for(led_counter=0;led_counter<=LED_NUMBER;led_counter++){

SPI_WRITE_TX(SPI0,0x924924);

SPI_WRITE_TX(SPI0, 0x924924);

SPI_WRITE_TX(SPI0, 0x924924);

while(SPI_IS_BUSY(SPI0));        

}

CLK_SysTickDelay(200);        

}





void send_led_commands(uint8_t Led_number, uint8_t G,uint8_t R,uint8_t B){

uint8_t led_counter=0;

uint32_t dataG,dataR,dataB=0;



dataG=data_bit8_to_bit24(G);  //Transform 8bit green data to 24bit data

dataR=data_bit8_to_bit24(R);  //Transform 8bit red data to 24bit data

dataB=data_bit8_to_bit24(B);  //Transform 8bit blue data to 24bit data



for(led_counter=0;led_counter<Led_number;led_counter++){

SPI_WRITE_TX(SPI0,0x924924);   //Send 0 bit turn off green color

SPI_WRITE_TX(SPI0, 0x924924);  //Send 0 bit turn off red color 

SPI_WRITE_TX(SPI0, 0x924924);  //Send 0 bit turn off blue color

while(SPI_IS_BUSY(SPI0));             // wait for communication

}



SPI_WRITE_TX(SPI0, dataG); // Send green color code

SPI_WRITE_TX(SPI0, dataR); // Send red color code

SPI_WRITE_TX(SPI0, dataB); // Send blue color code

while(SPI_IS_BUSY(SPI0));         // wait for communication



CLK_SysTickDelay(200);  //wait for 200us for reset code

}



unsigned int data_bit8_to_bit24(uint8_t data){

uint32_t conv_data=0;

int8_t x=0;

uint32_t bit0=4;  //100 

uint32_t bit1=6;  //110



for(x=7;x>=0;x--){

if (data&(1<<x))

conv_data=conv_data|(bit1<<(3*x));

else

conv_data=conv_data|(bit0<<(3*x));

}

return conv_data;

}



int8_t counter=0;

int main(void)

{

/* Unlock protected registers */

SYS_UnlockReg();

/* Init System, IP clock and multi-function I/O. */

SYS_Init();

/* Lock protected registers */

SYS_LockReg();

/* Init SPI */

SPI_Init();

send_array_clear();



while(1){



for(counter=LED_NUMBER-1;counter>=0;counter--){

send_led_commands(counter,255-counter*28,counter*28,0);

CLK_SysTickDelay(100000); //wait 100 miliseconds

}



CLK_SysTickDelay(1000000); //wait 3 seconds

CLK_SysTickDelay(1000000);

CLK_SysTickDelay(1000000);



send_array_clear(); //Turn off all LEDs on strip



CLK_SysTickDelay(1000000); //wait 1 second



}

}





void SYS_Init(void)

{

    /*---------------------------------------------------------------------------------------------------------*/

    /* Init System Clock                                                                                       */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Enable HIRC clock */

    CLK_EnableXtalRC(CLK_PWRCTL_HIRCEN_Msk);

                CLK_SetSysTickClockSrc(CLK_CLKSEL0_STCLKSEL_HIRC_DIV2);

    /* Waiting for HIRC clock ready */

    CLK_WaitClockReady(CLK_STATUS_HIRCSTB_Msk);



    /* Switch HCLK clock source to HIRC and HCLK source divide 1 */

    CLK_SetHCLK(CLK_CLKSEL0_HCLKSEL_HIRC, CLK_CLKDIV0_HCLK(1));



    /* Select HIRC as the clock source of UART0 */

    CLK_SetModuleClock(UART0_MODULE, CLK_CLKSEL1_UART0SEL_HIRC, CLK_CLKDIV0_UART0(1));



    /* Select PCLK1 as the clock source of SPI0 */

    CLK_SetModuleClock(SPI0_MODULE, CLK_CLKSEL2_SPI0SEL_PCLK1, MODULE_NoMsk);



    /* Enable SPI0 peripheral clock */

    CLK_EnableModuleClock(SPI0_MODULE);



    /*---------------------------------------------------------------------------------------------------------*/

    /* Init I/O Multi-function                                                                                 */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Set PB multi-function pins for UART0 RXD=PB.12 and TXD=PB.13 */

    SYS->GPB_MFPH = (SYS->GPB_MFPH & ~(SYS_GPB_MFPH_PB12MFP_Msk | SYS_GPB_MFPH_PB13MFP_Msk)) |

                    (SYS_GPB_MFPH_PB12MFP_UART0_RXD | SYS_GPB_MFPH_PB13MFP_UART0_TXD);



    /* Setup SPI0 multi-function pins */

    /* PA.3 is SPI0_SS,   PA.2 is SPI0_CLK,

       PA.1 is SPI0_MISO, PA.0 is SPI0_MOSI*/

    SYS->GPA_MFPL = (SYS->GPA_MFPL & ~(SYS_GPA_MFPL_PA3MFP_Msk |

                                       SYS_GPA_MFPL_PA2MFP_Msk |

                                       SYS_GPA_MFPL_PA1MFP_Msk |

                                       SYS_GPA_MFPL_PA0MFP_Msk)) |

                    (SYS_GPA_MFPL_PA3MFP_SPI0_SS |

                     SYS_GPA_MFPL_PA2MFP_SPI0_CLK |

                     SYS_GPA_MFPL_PA1MFP_SPI0_MISO |

                     SYS_GPA_MFPL_PA0MFP_SPI0_MOSI);



    /* Update System Core Clock */

    /* User can use SystemCoreClockUpdate() to calculate SystemCoreClock and CyclesPerUs automatically. */

    SystemCoreClockUpdate();

}



void SPI_Init(void)

{

    /*---------------------------------------------------------------------------------------------------------*/

    /* Init SPI                                                                                                */

    /*---------------------------------------------------------------------------------------------------------*/

    /* Configure as a master, clock idle low, 24-bit transaction, drive output on falling clock edge and latch input on rising edge. */

    /* Set IP clock divider. SPI clock rate = 2.5MHz */

    SPI_Open(SPI0, SPI_MASTER, SPI_MODE_0,24, SPI_CLK_FREQ);



    /* Enable the automatic hardware slave select function. Select the SS pin and configure as low-active. */

    SPI_EnableAutoSS(SPI0, SPI_SS, SPI_SS_ACTIVE_LOW);

}