STM32_Examples/Soft_SPI.c

/*
 * Soft_SPI.c
 *
 *  Created on: Nov 26, 2019
 *      Author: Adcis
 *
 *  SCK_Pin, MOSI_Pin, MISO_Pin, CS0_Pin and CS1_Pin required to define in project
 *
 *  Software SPI library for use with STM32 MCUs
 */
#include "main.h"
#include "Soft_SPI.h"
//#include "main.c"

void SOFT_Power(int,int);
void SOFT_SCK(unsigned int);										//rizeni SCK pinu
void SOFT_SPI(unsigned int);										//rizeni MOSI pinu
void SOFT_SPI_Send(unsigned int);								//odeslani zpravy po SPI
int SOFT_SPI_Receive(unsigned int);								//prijem zpravy po SPI
void SOFT_CS(unsigned int);										//chip select - 0 = DA prevodnik, 1 = AD prevodnik, cokoliv jineho = nezvoleno nic
void SOFT_SPI_CLK(unsigned int);									//1 puls _|-|_ na SCK


int SOFT_Power(int x, int y){
  		if (y == 0){
  			return 1;
  		}
  		else if (y % 2 == 0){
  			return SOFT_Power(x, y / 2) * SOFT_Power(x, y / 2);
  		}
  		else{
  			return x * SOFT_Power(x, y / 2) * SOFT_Power(x, y / 2);
  		}
}
/**
  * @brief  Controls SCK
  *
  * @param  var = set state of SCK
  *
  * @retval None
  */
void SOFT_SCK(unsigned int state){
  		if(state == 1){
  			GPIOB->BSRR = SCK_Pin;
  		}
  		else{
  			GPIOB->BRR = SCK_Pin;
  		}
}
/**
  * @brief  Controls MOSI
  *
  * @param  var = set state of MOSI
  *
  * @retval None
  */
void SOFT_SPI(unsigned int var){
  		if(var!=0){
  			GPIOB->BSRR = MOSI_Pin;
  		}
  		else{
  			GPIOB->BRR = MOSI_Pin;
  		}
}
/**
  * @brief  SPI CS control
  *
  * @param  cs = what cs pin to use
  *
  * @retval None
  */
void SOFT_CS(unsigned int cs){
  		if(cs == 0){
  			GPIOB->BSRR = CS1_Pin;
  			GPIOB->BRR = CS0_Pin;
  		}
  		else if(cs == 1){
  			GPIOB->BSRR = CS0_Pin;
  			GPIOB->BRR = CS1_Pin;
  		}
  		else{
  			GPIOB->BSRR = CS0_Pin;
  			GPIOB->BSRR = CS1_Pin;
  		}
}
/**
  * @brief  Sends SPI message
  *
  * @param  value = what byte to send
  *
  * @retval None
  */
void SOFT_SPI_Send(unsigned int value){
  		unsigned int valueBin[] = {0,0,0,0,0,0,0,0};
  		if(value >= 128){
  			valueBin[0] = 1;
  			value = value % 128;
  		}
  		if(value >= 64){
  			valueBin[1] = 1;
  			value = value % 64;
  		}
  		if(value >= 32){
  			valueBin[2] = 1;
  			value = value % 32;
  		}
  		if(value >= 16){
  			valueBin[3] = 1;
  			value = value % 16;
  		}
  		if(value >= 8){
  			valueBin[4] = 1;
  			value = value % 8;
  		}
  		if(value >= 4){
  			valueBin[5] = 1;
  			value = value % 4;
  		}
  		if(value >= 2){
  			valueBin[6] = 1;
  		}
  		valueBin[7] = value % 2;

  		SOFT_SCK(0);
  		SOFT_SPI(valueBin[0]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[1]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[2]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[3]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[4]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[5]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[6]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		SOFT_SPI(valueBin[7]);
  		SOFT_SCK(0);
  		SOFT_SCK(1);
  		GPIOB->BRR = MOSI_Pin;
  		SOFT_SCK(0);
}
/**
  * @brief  Recieves SPI message
  *
  * @param  bits = how long will received mesage be
  *
  * @retval uint16_t
  */
int SOFT_SPI_Receive(unsigned int bits){
  		uint8_t arr_bts[bits];
  		uint8_t sumarr[bits];
  		uint16_t sum;
  		for(int i=0; i<bits;i++){
  			SOFT_SCK(1);
  				if(HAL_GPIO_ReadPin(GPIOB, MISO_Pin) == 1){
  					arr_bts[i] = 1;
  				}
  				else{
  					arr_bts[i] = 0;
  				}
#ifndef FAST_SPI
  			sumarr[i] = arr_bts[i] * power(2 , bits - i - 1);
#endif
  			SOFT_SCK(0);
  		}
#ifdef FAST_SPI
  		for(int i = 0; i < bits; i++){
  			sumarr[i] = arr_bts[i] * SOFT_Power(2 , bits - i - 1);
  		}
#endif
//receive string
  		if(bits==12){
  			sum = sumarr[0]+sumarr[1]+sumarr[2]+sumarr[3]+sumarr[4]+sumarr[5]+sumarr[6]+sumarr[7]+sumarr[8]+sumarr[9]+sumarr[10]+sumarr[11];
  		}
  		else if(bits==16){
  			sum = sumarr[0]+sumarr[1]+sumarr[2]+sumarr[3]+sumarr[4]+sumarr[5]+sumarr[6]+sumarr[7]+sumarr[8]+sumarr[9]+sumarr[10]+sumarr[11]+sumarr[12]+sumarr[13]+sumarr[14]+sumarr[15];
  		}
  		else if(bits==8){
  			sum = sumarr[0]+sumarr[1]+sumarr[2]+sumarr[3]+sumarr[4]+sumarr[5]+sumarr[6]+sumarr[7];
  		}
  		else{
  			sum = 0;
  		}
  		return sum;
}
/**
  * @brief  SPI clk
  *
  * @param  cycles = how many cycles to make
  *
  * @retval None
  */
void SOFT_SPI_CLK(unsigned int cycles){
  		for(int i=0;i<cycles;i++){
  			SOFT_SCK(1);
  			for(int j=0;j<1;j++);
  			SOFT_SCK(0);
  		}
}