Просмотр исходного текста страницы Урок 5.2: Работаем с EEPROM-памятью

'''eeprom_test.c''':
<source lang="c">
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

void usart0_init( uint32_t baudrate );
void usart0_putchar( uint8_t data );
uint8_t usart0_getchar( void );
void usart0_putstr( char *str );
void usart0_getstr( char *str, uint8_t length );

void eeprom_write( uint16_t address, uint8_t data );
uint8_t eeprom_read( uint16_t address );

void usart0_init( uint32_t baudrate )
{
   uint16_t bauddiv = ( ( F_CPU + ( baudrate * 8L ) ) / ( baudrate * 16L ) - 1 );
   UBRRL |= bauddiv;
   UBRRH |= ( bauddiv >> 8 ); 
   UCSRB |= ( 1 << TXEN ) | ( 1 << RXEN );
}

void usart0_putchar( uint8_t data )
{
   while( !( UCSRA & ( 1 << UDRE ) ) );

   UDR = data;
}

uint8_t usart0_getchar( void )
{
   while( !( UCSRA & ( 1 << RXC ) ) );
   
   return UDR;
}

void usart0_putstr( char *str ) 
{
   while( *str ) 
      usart0_putchar( *str++ );
}

void usart0_getstr( char *str, uint8_t length ) 
{
   while( length )
   {
      *str = usart0_getchar();
      
      if( *str == '\n' || *str == '\r' )
         break;
      
      str++;
      length--;
   }
}

void eeprom_write( uint16_t address, uint8_t data )
{
   while( EECR & ( 1 << EEWE ) );
   EEAR = address;
   EEDR = data;
   EECR |= ( 1 << EEMWE );
   EECR |= ( 1 << EEWE );
}

uint8_t eeprom_read( uint16_t address )
{
   while( EECR & ( 1 << EEWE ) );
   EEAR = address;
   EECR |= ( 1 << EERE );
   return EEDR;   
}

int main( void )
{
   char str_enter_cmd[] = "Enter command ( 'r' to read, 'w' to write ): ";
   char str_enter_addr[] = "Enter address: ";
   char str_enter_value[] = "Enter value: ";
   char str_default[] = "Wrong command, try again!\n\r";
   char str_value[] = "Value is: ";
   
   usart0_init( 9600 );
   
   while( 1 )
   {
      char buffer[8] = { 0 };
      int addr = 0;
      uint8_t value = 0;
      
      usart0_putstr( str_enter_cmd );
      
      switch( usart0_getchar() )
      {
      case 'r':
         usart0_putchar( '\r' );
         
         usart0_putstr( str_enter_addr );
         
         usart0_getstr( buffer, sizeof( buffer ) );
         
         addr = atoi( buffer );
         
         memset( buffer, 0, sizeof( buffer ) );
         
         value = eeprom_read( addr );
         
         usart0_putstr( str_value );
         
         usart0_putstr( itoa( value, buffer, 10 ) );
         
         break;
         
      case 'w':
         usart0_putchar( '\r' );
                  
         usart0_putstr( str_enter_addr );
         
         usart0_getstr( buffer, sizeof( buffer ) );
         
         addr = atoi( buffer );
         
         memset( buffer, 0, sizeof( buffer ) );
         
         usart0_putchar( '\r' );
         
         usart0_putstr( str_enter_value  );
         
         usart0_getstr( buffer, sizeof( buffer ) );
         
         value = atoi( buffer );
         
         memset( buffer, 0, sizeof( buffer ) );
         
         eeprom_write( addr, value );
         
         break;
         
      default:
         usart0_putstr( str_default );
         break;
      }
      
      usart0_putchar( '\r' );
      
   }
   
   return 0;
}</source>