Mikroelektronika MIKROE-742 데이터 시트

The example demonstrates Software I

2

C Library routines usage. The AVR MCU is

connected (SCL, SDA pins) to PCF8583 RTC (real-time clock). Program reads date
and time are read from the RTC and prints it on Lcd.

program RTC_Read;

var seconds, minutes, hours, day, month, year : byte;    // Global
date/time variables

// Software I2C connections
var Soft_I2C_Scl_Output    : sbit at PORTC.B0;

Soft_I2C_Sda_Output    : 

sbit at PORTC.B1; 

Soft_I2C_Scl_Input     : 

sbit at PINC.B0;

Soft_I2C_Sda_Input     : 

sbit at PINC.B1;

Soft_I2C_Scl_Direction : 

sbit at DDRC.B0:

Soft_I2C_Sda_Direction : 

sbit at DDRC.B1;

// End Software I2C connections

// Lcd module connections
var LCD_RS : sbit at PORTD.B2;

LCD_EN : 

sbit at PORTD.B3;

LCD_D4 : 

sbit at PORTD.B4;

LCD_D5 : 

sbit at PORTD.B5;

LCD_D6 : 

sbit at PORTD.B6;

LCD_D7 : 

sbit at PORTD.B7;

LCD_RS_Direction : 

sbit at DDRD.B2;

LCD_EN_Direction : 

sbit at DDRD.B3

LCD_D4_Direction : 

sbit at DDRD.B4;

LCD_D5_Direction : 

sbit at DDRD.B5;

LCD_D6_Direction : 

sbit at DDRD.B6;

LCD_D7_Direction : 

sbit at DDRD.B7;

// End Lcd module connections

//--------------------- Reads time and date information from RTC

(PCF8583)
procedure Read_Time();

Soft_I2C_Start();      // Issue start signal

Soft_I2C_Write(0xA0);    // Address PCF8583, see PCF8583 datasheet

Soft_I2C_Write(2);     // Start from address 2

Soft_I2C_Start();      // Issue repeated start signal

Soft_I2C_Write(0xA1);  // Address PCF8583 for reading R/W=1}

seconds := Soft_I2C_Read(1);    

// Read seconds byte

minutes := Soft_I2C_Read(1);    

// Read minutes byte

hours := Soft_I2C_Read(1);        

// Read hours byte

day := Soft_I2C_Read(1);       

// Read year/day byte

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- SOFTWARE AND HARDWARE SOLUTIONS FOR EMBEDDED WORLD

CHAPTER 6