/* Sample program of I2C access to RTC chip on Wytec EduBase board.
 * This program clears the second counter in BQ32000 RTC chip.
 * The second counter is read every second and print it.
 * The address of second counter in RTC is 0.
 * The second counter increments once every second and has the BCD format
 * 
 * This program uses Energia Wire library.
 */
 
#include <Wire.h>

char SLAVEADDR = 0x68;  // RTC BQ32000 address

void setup()
{
    // patch for a bug in Wire.begin()
    // http://forum.43oh.com/topic/7147-i2c-on-stellaris-launchpad/
        Wire.begin(1);        
        Wire.setModule(1);
    
    Wire.begin();
    Serial.begin(9600);  // start serial for output
  
    // the following pair clears the second counter in RTC
    const uint8_t data[2] = {0, 0};  // address 0, data 0
    Wire.beginTransmission(SLAVEADDR); // start talking to RTC
    Wire.write(data, 2);       // reset second count  
    Wire.endTransmission();    // stop
    delay(500);
}

void loop()
{
    // set address counter in slave to 0 (second counter)
    Wire.beginTransmission(SLAVEADDR); // start talking to RTC
    Wire.write(0);       // send address 0 for second counter in RTC 
    Wire.endTransmission();    // stop
    
    Wire.requestFrom(SLAVEADDR, 1);    // request 1 byte from slave
  
    while(Wire.available())   // read while there is data
    { 
        char c = Wire.read();   // read a byte
        Serial.print(c, HEX);   // print the byte
        Serial.print('.');
        if ((c & 0x0F) == 9)
            Serial.println();
    }

    delay(1000);
}