Subversion Repositories LedShow

/*

 * leds.c

 *

 *  Created on: 7 Jul 2019

 *      Author: Mike

 */

#include "main.h"

#include "leds.h"

// Target clock rate 800 kHz

#define SPICLOCK 9000000UL

// one clock of SPI is 166nS

#define TSPI (1000000000UL/SPICLOCK)

// reset period is 50000nS

#define TRESET 50000

// stop period is  20000nS

#define TSTOP  50000

// total bit period is 1250nS or 1/800kHz

#define TBIT  1250

// to produce '0' value go high for 400nS, low for 850nS

#define T0H    400

#define T0L    850

// to produce '1' value go high for 850nS, low for 400nS

#define T1H    850

#define T1L    400

#define BUFFER_SIZE 1000

uint8_t buffer [BUFFER_SIZE];

// byte pointer

unsigned bufPtr;

// bit index pointer

uint8_t bitPtr;

// bit transmission time offset from start of transmission

unsigned SPItime = 0;

unsigned RealTime = 0;

static volatile uint8_t busy = 0;

void initCode(void)

{

        bufPtr = 0;

        bitPtr = 0;

        SPItime  = 0;

        RealTime = 0;

}

// send a '1' or '0' on SPI bus

void codeBit(uint8_t val, unsigned until)

{

        // calculate true limit time

        RealTime += until;

        while(SPItime<= RealTime)

        {

        if(val)

          buffer[bufPtr] |= (1<<bitPtr);

        else

      buffer[bufPtr] &= ~(1<<bitPtr);

        bitPtr++;

        if(bitPtr == 8)

        {

                bitPtr = 0;

                bufPtr ++;

        }

        // accumulate transmission time on SPI bus

        SPItime += TSPI;

        if(bufPtr >= BUFFER_SIZE)

                bufPtr = BUFFER_SIZE-1; // limit

        }

}

void codeReset (void)

{

                codeBit(0,TRESET);

}

void codeStop (void)

{

        codeBit(0,TSTOP);

}

// send a single Run Length code bit

void codeRL(uint8_t bit)

{

        unsigned lim = bit ? T1H : T0H;

        codeBit(1,lim);

        codeBit(0,TBIT-lim);

}

// code a byte using the RL code

void codeRLByte(uint8_t val)

{

        uint8_t i;

                for (i=0; i<8; i++)

                {

                        codeRL(val & 0x80);

                        val<<=1;

                }

}

void codeFRGBW(frgbw_t led )

{

                codeRLByte(((uint16_t)(led.green) * led.fader)/256);

                codeRLByte(((uint16_t)(led.red) * led.fader)/256);

                codeRLByte(((uint16_t)(led.blue) * led.fader)/256);

                codeRLByte(((uint16_t)(led.white) * led.fader)/256);

}

frgbw_t led0 = { 128, 0, 0, 0, 0 };

frgbw_t led1 = { 128, 0, 0, 0, 2 };

frgbw_t ledZ = { 0,0,0,0 };

void sendLeds()

{

        initCode();

        codeReset();

    led0.green++;

///     led0.fader++;

        led1.red++;

//      led1.fader--;

        codeFRGBW(led0);

        codeFRGBW(led1);

        // send terminal

        codeStop();

    busy= 1;

        HAL_SPI_Transmit_DMA(&hspi1,buffer,bufPtr);

  //

        while(busy) {};

}

void HAL_SPI_TxCpltCallback( SPI_HandleTypeDef * hspi)

{

        (void ) hspi;

        busy = 0;

}