MAX7219, 8-digit 7 segment LED display SPI programming

[BGURR.1]

Could some one help me in making SPI C-program of MAX7219, 8 digit 7 segment display using STM32F401RE

 .

i have written this code in arm keil (µVision 5) it is not working, could someone help me please:

#include"stm32f4xx.h"

#include<stdio.h>

#include<string.h>

void Led_write (char data);

void delayMs(int n);

int main (void)

{

char num[] = {0x7e,0x60,0x6d,0x78,0x33,0x5b,0x5f,0x70,0x7f,0x7b};

RCC->AHB1ENR |= 0x0001;

RCC->AHB2ENR |= 0x1000;

GPIOA->MODER &= ~0xcf00;

GPIOA->MODER |= 0x8900;

GPIOA->AFR[0] &= ~0xf0f00000;

GPIOA->AFR[0] |= 0x50500000;

SPI1->CR1 = 0x031c;

SPI1->CR2 = 0x00;

SPI1->CR1 |= 0x40;

while(1)

{

for(int i=0;i<10;i++)

{

Led_write(num[i]);

delayMs(100);

}

}

}

void Led_write (char data)

{

while(!(SPI1->SR & 2));

GPIOA->BSRR = 0x00100000;

SPI1->DR = 0x0900 | data;

while(SPI1->SR & 0x80);

GPIOA->BSRR = 0x00000010;

}

void delayMs(int n)

{

for (int i=0;i<n;i++)

for (int j=0;j<3195;i++);

}

[waclawek.jan]

You need to enable SPI clock in RCC.

It's probably better to use the symbols defined in the device header, rather than numbers, for the various register bitfields values.

JW

[BGURR.1]

hello,

I have enable the SPI1 clock in RCC using RCC->AHB2ENR |= 0x1000; using this statement.

and i have tried new code, Please help me.

/* Micro controller: STM32F401RE

PA7  DIN

  PA5  SCK

  PA4  SS   

driver MAX7219: 8 digit 7 segment display */

#include"stm32f4xx.h"

#include<stdio.h>

void init_SPI1 (void);        // initialization of SPI1

void write_SPI1 (uint16_t data);   // writing data to SPI1

void delayMs (uint16_t n);      // generating delay

uint16_t shut_Addr = 0x0c00;  //Normal operation

uint16_t norm_Addr = 0x0c01;  //Normal operation 

uint16_t intn_Addr = 0x0a05;  //intensity register

//uint16_t code_Addr = 0x0900;  //address of decode mode

uint16_t dig1_Addr = 0x0100;  //selecting digit 1

int main (void)

{

init_SPI1();

write_SPI1(norm_Addr);

write_SPI1(intn_Addr);  // for intensity: intensity is 0x0e

while(1)

{

write_SPI1 (dig1_Addr | 0x01);  // for DIGIT1: sending value 3

}

}

void write_SPI1 (uint16_t data)  //writing something to MAX7219

{

while(!(SPI1->SR & 0x02));   //wait until transfer buffer empty

GPIOA->BSRR = 0x00100000;   //Slave select = 0

SPI1->DR = data;

while(SPI1->SR & 0x80);    //wait for transmission done

GPIOA->BSRR = 0x00000010;   //Slave select = 1

}

void init_SPI1(void)   //initializing the MAX7219

{

RCC->AHB1ENR |= 0x0001;  //Enabling clock of GPIOA

RCC->APB2ENR |= 0x1000;  //Enabling clock of SPI1

GPIOA->MODER &= ~0xcf00;  //resetting PA5, PA7: Alternate function and PA4: output function

GPIOA->MODER |= 0x8900;  //set PA5, PA7: Alternate function and PA4: output function

GPIOA->AFR[0] &= ~0xf0f00000;  

GPIOA->AFR[0] |= 0x50500000;  //set PA5, PA7: Alternate function

SPI1->CR1 = 0x0b14;      //seting baudrate, 16 bit format

SPI1->CR2 = 0x0000;

SPI1->CR1 |= 0x0040;      //Enabling SPI1

}

void delayMs(uint16_t n)     //generting of delay in n ms

{

for (int i=0; i<n; i++)

for (int j=0; j<3195; i++);

}

[BGURR.1]

Following code is attached for reference