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//>>> The latest version of this code can be found at https://github.com/jcw/ !!

// Hooking up a DS1307 (5V) or DS1340Z (3V) real time clock via I2C.

// see http://jeelabs.org/cp1

// 2009-09-17 <jcw@equi4.com> http://opensource.org/licenses/mit-license.php

// $Id$

// the real-time clock is connected to port 1 in I2C mode (AIO = SCK, dIO = SDA)

#include <Ports.h>

#include <RF12.h> // needed to avoid a linker error :(

PortI2C myport (1 /*, PortI2C::KHZ400 */);

DeviceI2C rtc (myport, 0x68);

static byte bin2bcd (byte val) {

    return val + 6 * (val / 10);

}

static byte bcd2bin (byte val) {

    return val - 6 * (val >> 4);

}

static void setDate (byte yy, byte mm, byte dd, byte h, byte m, byte s) {

    rtc.send();

    rtc.write(0);

    rtc.write(bin2bcd(s));

    rtc.write(bin2bcd(m));

    rtc.write(bin2bcd(h));

    rtc.write(bin2bcd(0));

    rtc.write(bin2bcd(dd));

    rtc.write(bin2bcd(mm));

    rtc.write(bin2bcd(yy));

    rtc.write(0);

    rtc.stop();

}

static void getDate (byte* buf) {

	rtc.send();

	rtc.write(0);

    rtc.stop();

	rtc.receive();

    buf[5] = bcd2bin(rtc.read(0));

    buf[4] = bcd2bin(rtc.read(0));

    buf[3] = bcd2bin(rtc.read(0));

    rtc.read(0);

    buf[2] = bcd2bin(rtc.read(0));

    buf[1] = bcd2bin(rtc.read(0));

    buf[0] = bcd2bin(rtc.read(1));

    rtc.stop();

}

void setup() {

    Serial.begin(57600);

    Serial.println("\n[rtc_demo]");

    // test code:

    setDate(9, 9, 17, 13, 18, 0);

}

void loop() {

    byte now[6];

    getDate(now);

    Serial.print("rtc");

    for (byte i = 0; i < 6; ++i) {

        Serial.print(' ');

        Serial.print((int) now[i]);

    }

    Serial.println();

	delay(1000);

}