MAX7219softlib

/***
STM32 microcontrollers Course

Author:  Julio Alexander Aguilar Angulo
Contents:  Useful routines to implement control a MAX7219 spi controller without the use of the spi peripheral
( All is based on loops and masking!!) [it's up to you to do the rest !!! good luck]

***/
// declarations based on the ISEN32 board hardware: portA
#define ckmask 1<<5;
#define datmask 1<<7;
#define max7219load 1<<8; 
#define Chip_Load   GPIOA->BSRRH |= max7219load;  //%10000000; CS=0
#define Chip_UnLoad GPIOA->BSRRL |= max7219load;  //%01111111; CS=1

//------------------
void SendData(uint8_t data)
{
uint8_t LOOP, FLAG;
    GPIOA->BSRRH |= ckmask;//SH_CLK = 0;
 for (LOOP=0; LOOP<8; LOOP++){
    GPIOA->BSRRH |= 1<<5;//SH_CLK = 0;
    FLAG=data&0x80;//because max7219 need MSb first !!
    if(FLAG==0){ GPIOA->BSRRH |= datmask;}// data=0
    else       { GPIOA->BSRRL |= datmask;}// data=1
    data <<= 1;
    GPIOA->BSRRL |= ckmask;//SH_CLK = 1;
//delay();   
 }
 }

static void SPI_write(uint8_t add, uint8_t data)
{
  Chip_UnLoad;//1
  Chip_Load;//0
  SendData(add);
  SendData(data);
  Chip_UnLoad;//1
}