Real Time Clock Module
This Module can be used to plug a Real Time Clock into your project. Connect the clock to your I2C-Pins (SCL, SDA)
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Source - modClock
/**************************************************************************************************
*
* Real Time Clock
*
* Version: 1.0.0 - January 2009
* Author: Etienne Ribeiro / tutorial assistant caad / eribeiro[at]ethz.ch
* (based on Code from Maurice Ribble)
* (http://www.glacialwanderer.com/hobbyrobotics)
* Supervisor: Christoph Wartmann / chair for caad - ETH Zürich / wartmann[at].arch.ethz.ch
*
* Desc: This Module can be used to plug a Real Time Clock to your project. Connect the
* clock to your I2C-Pins (SCL, SDA).
*
* Methodes: void iniWire ()
* Initializes wire. Must be called in setup().
* void setDate(byte second, byte minute, byte hour, byte dayOfWeek, byte dayOfMonth, byte month, byte year)
* Set date. Not needed to call, if clock has already be ajusted.
* void getDate(byte *second, byte *minute, byte *hour, byte *dayOfWeek, byte *dayOfMonth, byte *month, byte *year)
* Get date. Parameters are return parameters. They must be called with &var1, & var2,...
*
***************************************************************************************************/
#include <TwoWire.h>
#define DS1307_I2C_ADDRESS 0x68
// Starts Wire. Must be called in setup
void iniWire () {
Wire.begin();
}
// 1) Sets the date and time on the ds1307
// 2) Starts the clock
// 3) Sets hour mode to 24 hour clock
// Assumes you're passing in valid numbers
void setDate(byte second, byte minute, byte hour, byte dayOfWeek, byte dayOfMonth, byte month, byte year) {
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.send(0);
Wire.send(decToBcd(second)); // 0 to bit 7 starts the clock
Wire.send(decToBcd(minute));
Wire.send(decToBcd(hour)); // If you want 12 hour am/pm you need to set
// bit 6 (also need to change readDateDs1307)
Wire.send(decToBcd(dayOfWeek));
Wire.send(decToBcd(dayOfMonth));
Wire.send(decToBcd(month));
Wire.send(decToBcd(year));
Wire.endTransmission();
}
// Gets the date and time from the ds1307
void getDate(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year)
{
// Reset the register pointer
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.send(0);
Wire.endTransmission();
Wire.requestFrom(DS1307_I2C_ADDRESS, 7);
// A few of these need masks because certain bits are control bits
*second = bcdToDec(Wire.receive() & 0x7f);
*minute = bcdToDec(Wire.receive());
*hour = bcdToDec(Wire.receive() & 0x3f); // Need to change this if 12 hour am/pm
*dayOfWeek = bcdToDec(Wire.receive());
*dayOfMonth = bcdToDec(Wire.receive());
*month = bcdToDec(Wire.receive());
*year = bcdToDec(Wire.receive());
}
// Stops the DS1307, but it has the side effect of setting seconds to 0
// Probably only want to use this for testing
/*void stopDs1307()
{
Wire.beginTransmission(DS1307_I2C_ADDRESS);
Wire.send(0);
Wire.send(0x80);
Wire.endTransmission();
}*/
// Convert normal decimal numbers to binary coded decimal
byte decToBcd(byte val) {
return ( (val/10*16) + (val%10) );
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val) {
return ( (val/16*10) + (val%16) );
}
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Source - Main
/**************************************************************************************************
*
* Real Time Clock
*
* Version: 1.0.0 - January 2009
* Author: Etienne Ribeiro / tutorial assistant caad / eribeiro[at]ethz.ch
* (based on Code from Maurice Ribble)
* Supervisor: Christoph Wartmann / chair for caad - ETH Zürich / wartmann[at].arch.ethz.ch
*
* Desc: This Module can be used to plug a Real Time Clock to your project. Connect the
* clock to your I2C-Pins (SCL, SDA).
*
***************************************************************************************************/
//
// Setup
void setup() {
// LED (2 * blink)
pinMode(48, OUTPUT);
digitalWrite(48, HIGH);
delay(200);
digitalWrite(48, LOW);
delay(200);
digitalWrite(48, HIGH);
// Initialize Timer
iniWire ();
Serial.begin(9600);
// Set Clock time (only neede to ajust the clock)
/*
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
second = 45; minute = 3; hour = 7; dayOfWeek = 5; dayOfMonth = 17; month = 4; year = 8;
setDate (second, minute, hour, dayOfWeek, dayOfMonth, month, year);
*/
}
//
// Loop
void loop() {
// Read Data from Clock
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
getDate(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month, &year);
// Have a break
delay(1000);
}