Hello. I am programming my DS1307 with my Arduino. I have used the following source code:
// Written by John Boxall from http://tronixstuff.com
#include "Wire.h"
#define DS3231_I2C_ADDRESS 0x68
// Convert normal decimal numbers to binary coded decimal
byte decToBcd(byte val){
return( (val/1016) + (val%10) );
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val){
return( (val/1610) + (val%16) );
}
void setup(){
Wire.begin();
Serial.begin(9600);
// set the initial time here:
// DS3231 seconds, minutes, hours, day, date, month, year
setDS3231time(00,00,01,1,01,1,19);
}
void setDS3231time(byte second, byte minute, byte hour, byte dayOfWeek, byte
dayOfMonth, byte month, byte year){
// sets time and date data to DS3231
Wire.beginTransmission(DS3231_I2C_ADDRESS);
Wire.write(0); // set next input to start at the seconds register
Wire.write(decToBcd(second)); // set seconds
Wire.write(decToBcd(minute)); // set minutes
Wire.write(decToBcd(hour)); // set hours
Wire.write(decToBcd(dayOfWeek)); // set day of week (1=Sunday, 7=Saturday)
Wire.write(decToBcd(dayOfMonth)); // set date (1 to 31)
Wire.write(decToBcd(month)); // set month
Wire.write(decToBcd(year)); // set year (0 to 99)
Wire.endTransmission();
}
void readDS3231time(byte *second,
byte *minute,
byte *hour,
byte *dayOfWeek,
byte *dayOfMonth,
byte *month,
byte *year){
Wire.beginTransmission(DS3231_I2C_ADDRESS);
Wire.write(0); // set DS3231 register pointer to 00h
Wire.endTransmission();
Wire.requestFrom(DS3231_I2C_ADDRESS, 7);
// request seven bytes of data from DS3231 starting from register 00h
*second = bcdToDec(Wire.read() & 0x7f);
*minute = bcdToDec(Wire.read());
*hour = bcdToDec(Wire.read() & 0x3f);
*dayOfWeek = bcdToDec(Wire.read());
*dayOfMonth = bcdToDec(Wire.read());
*month = bcdToDec(Wire.read());
*year = bcdToDec(Wire.read());
}
void displayTime(){
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;
// retrieve data from DS3231
readDS3231time(&second, &minute, &hour, &dayOfWeek, &dayOfMonth, &month,
&year);
// send it to the serial monitor
Serial.print(hour, DEC);
// convert the byte variable to a decimal number when displayed
Serial.print(":");
if (minute<10){
Serial.print("0");
}
Serial.print(minute, DEC);
Serial.print(":");
if (second<10){
Serial.print("0");
}
Serial.print(second, DEC);
Serial.print(" ");
Serial.print(dayOfMonth, DEC);
Serial.print("/");
Serial.print(month, DEC);
Serial.print("/");
Serial.print(year, DEC);
Serial.print(" Day of week: ");
switch(dayOfWeek){
case 1:
Serial.println("Sunday");
break;
case 2:
Serial.println("Monday");
break;
case 3:
Serial.println("Tuesday");
break;
case 4:
Serial.println("Wednesday");
break;
case 5:
Serial.println("Thursday");
break;
case 6:
Serial.println("Friday");
break;
case 7:
Serial.println("Saturday");
break;
}
}
void loop(){
displayTime(); // display the real-time clock data on the Serial Monitor,
delay(1000); // every second
}
It works perfectly fine with my DS1307.
Now, I would like to make a trigger-point with an if-statement. I want to (as an example) make an LED turn on everytime the second-pointer is at 20. Everytime the second-counter reaches 20, i would like to make the LED turn on.
I tried implementing it by writing:
int redPin = 2;
void setupLight(){
pinMode(redPin, HIGH)
}
So now I have the pin-number for the LED and made it high everytime the function will be called. But I'm having trouble making it work. I was thinking about writing something like this:
void loop(){
if (*second == 20){
setupLight();
}
Is this possible? It doesn't work when I try to verify the code in the Arduino IDE.
