[SOLVED] [C] problem with MAX187 & ATmega16

[jirkaj4]

Hello.
I'm trying to communicate with the AD converter Max187 and ATmega16. But not me.

The display is no number, no nothing. So I think that with the AD converter establish a connection.

Do you know where the problem might be?
It is about connections: ATmega16 - SPI - Max187.
16MHz crystal. Codes attach here:

#include <avr/io.h>  
#include <stdio.h>
#include <util/delay.h>  
#include <avr/interrupt.h>  

#include "lcd.h"	//Communication with LCD2004
#include "spi.h"	//Communication on SPI bus
//set CPOL = 0 and CPHA = 0 from datasheet

unsigned char data;		//value of nuber from MAX187
char buffer[50];

void inicializace(){
        InitSPI();  //INIT SPI 
	lcd_init(LCD_DISP_ON);	//INITLCD
}

int main(){
	inicializace();

while(1){
	
	//read data from MAX187
       SELECT();       // Select SS slave         
       data = ReadByteSPI();   //read data from SPI  
       DESELECT();     // Stop SS Slave  

	_delay_ms(10);	//small delay

        //show value on LCD
	lcd_gotoxy(0,1);
	printf(buffer,"%d",data);
	lcd_puts(buffer);
      
}return(0);
}

And the whole project can be downloaded here [AVR Studio 4]
View attachment program.rar.

thank you

 

[jirkaj4]

After a few hours of work, I solved the problem. Library "spi.h" I deleted it and replaced it with the following:

#include <avr/io.h>  
#include <stdio.h>
#include <util/delay.h>  
#include <avr/interrupt.h>  

#include "lcd.h"	//knihovna pro komunikaci s LCD 2004


// Mega16 Pinout
#define MOSI	4
#define MISO	6
#define SCLK	7
#define SS		4

char buffer[50];

unsigned int get_adc(unsigned char adata)
{
	static unsigned int temp=0;
	
	PORTB &= ~(1<<SS);					// SET CS do 0 (aktivovani ADC) 
	SPDR = adata;						// vložit data do odesílací registru
	while(!(SPSR & (1<<SPIF)));			        // Poslat 1 byte přes HW SPI a čeka na tx
	temp = SPDR;						// přijatá data nahraje do proměnné TEMP
	temp = temp << 8;					// posune proměnnou TEMP o 8 vlevo
	SPDR = adata;						// vloží data do odesílacího registru
	while(!(SPSR & (1<<SPIF)));			        // Poslat 1 byte přes HW SPI a čeka na tx	
	temp |= SPDR;						// přijatá data nahraje do proměnné TEMP
	PORTB |= (1<<SS);					// nastavi CS do 1 a tim zakaze ADC 
	return temp;						// navratí hodnotu ADcka
}



void spim_init(void)
{
	// SET PORT B jako výstup 
	DDRB |= (1<<MOSI) | (1<<SCLK) | (1<<SS);
	// SET MISO jako vstup
	DDRB &= ~(1<<MISO); 
	// Povoleni SPI, SPI Master, SPI CLK XTAL/16, LSB First
	SPCR |= (1<<SPE)|(1<<MSTR)|(1<<SPR0);		
	// nastaveni funkcniho registra SPI (SPCR), CPHA a CPOL v log 0
	SPCR &= ~ (1<<CPOL); SPCR &= ~ (1<<CPHA);	
	// CS HIGH protože SPI ADS je aktivní v 0
	PORTB |= (1<<SS);		 
}

int main (void)
{
	static unsigned int adc_value=0;	// value AD prevodniku
	
	lcd_init(LCD_DISP_ON);	//inicializace LCD
	spim_init();			// Inicializace SPI jako MASTER

	for(;;){
	adc_value = get_adc(0xFF);				// získání hodnoty z AD prevodniku

	lcd_gotoxy(0,1);
	sprintf(buffer,"%d",adc_value);
	lcd_puts(buffer);	

	}
}