Posts Tagged ‘clock’
Kids Clock V2.0
The KidsClock v2.0
A big problem with my first version of the KidsClock was that despite my efforts to track time accurately, it was drifting a few minutes everyday. This is because the Arduino does not come with a built-in real time clock like full scale computers.
To fix that problem I added a real time clock chip, the DS1307, to my circuit. Using this chip and some libraries from the Arduino community have make the code a lot simpler.
The KidsClock v2.0 Circuit
The ds1307 circuit has a battery that allows your Arduino to be unpluged without losing time. This is a great improvement over the previous version.
The libraries I use can be found at:
http://code.google.com/p/arduino-time/
To set the time of the RTC to the local time I used this sample project:
http://combustory.com/wiki/index.php/RTC1307_-_Real_Time_Clock
Following is the code of the application. The clock red led turns on at 20:00h and the green led at 6:30 in the morning using the Alarm library.
/*
* kidsclock2.pde
*/
#include
#include
#include
#include
#define RED_LED 8
#define GREEN_LED 11
#define BOARD_LED 13
// 6:30 am every day
#define mh 6
#define mm 30
// 20:00 pm every day
#define eh 20
#define em 0
int boardLedState = HIGH;
void setup()
{
Serial.begin(9600);
setSyncProvider(RTC.get); // the function to get the time from the RTC
if(timeStatus()!= timeSet)
Serial.println("Unable to sync with the RTC");
else
Serial.println("RTC has set the system time");
Alarm.alarmRepeat(mh,mm,0, MorningAlarm);
Alarm.alarmRepeat(eh,em,0,EveningAlarm);
InitLEDs();
}
void InitLEDs()
{
pinMode(RED_LED, OUTPUT);
pinMode(GREEN_LED, OUTPUT);
pinMode(BOARD_LED, OUTPUT);
if( (hour() == mh && minute() >= mm ) ||
(hour() == eh && minute() < em) || (hour() > mh && hour() < eh) )
{
digitalWrite(RED_LED, LOW);
digitalWrite(GREEN_LED, HIGH);
}
else
{
digitalWrite(RED_LED, HIGH);
digitalWrite(GREEN_LED, LOW);
}
}
void MorningAlarm()
{
Serial.println("Alarm: - Morning");
digitalWrite(RED_LED, LOW);
digitalWrite(GREEN_LED, HIGH);
}
void EveningAlarm()
{
Serial.println("Alarm: - Evening");
digitalWrite(RED_LED, HIGH);
digitalWrite(GREEN_LED, LOW);
}
void loop()
{
boardLedState = !boardLedState;
digitalWrite( BOARD_LED, boardLedState);
digitalClockDisplay();
Alarm.delay(1000); // wait one second between clock display
}
void digitalClockDisplay()
{
// digital clock display of the time
Serial.print(hour());
printDigits(minute());
printDigits(second());
Serial.println();
}
void printDigits(int digits)
{
// utility function for digital clock display: prints preceding colon and leading 0
Serial.print(":");
if(digits < 10)
Serial.print('0');
Serial.print(digits);
}
Kids Clock (Update)
Kids Clock Art
I integrated the Kids Clock into my kid’s last piece of “art” … I hope he will not mind having screw tips in it. The gadget works pretty good! Never woke up before time since he started using it!
Kids Clock
Kids Clock Arduino
Ok, that one is not rocket science but it realy realy worth the 20$ Arduino micro controller I used to make that kids clock.
The idea here is to make sure my 4 years old kid will not wake up at 3:30AM because he has confused the small needle with big needle. The code is real simple … red LED on before wake up time … green LED on after wake up time.
Following is the code … of course that could have been a lot more complicated but this is doing the job just fine. Stay tuned for future enhancements.
#include <avr/interrupt.h>
#include <avr/io.h>
#define INIT_TIMER_COUNT 6
#define RESET_TIMER2 TCNT2 = INIT_TIMER_COUNT
#define RED_LED 8
#define GREEN_LED 11
#define BOARD_LED 13
#define NIGHT_TIME 36000 // 10*60*60
int led13 = HIGH;
long counter = 0;
long stepStack = 0;
long seconds = 0;
// Aruino runs at 16 Mhz, so we have 1000 Overflows per second...
// 1/ ((16000000 / 64) / 256) = 1 / 1000
ISR(TIMER2_OVF_vect) {
RESET_TIMER2;
counter++;
if(!(counter%1000))
{
// enqueue step message
stepStack++;
}
};
void startup()
{
int led = 0;
for(int i=0; i<5; i++)
{
digitalWrite(RED_LED, led);
digitalWrite(GREEN_LED, led^1);
led ^= 1;
delay(500);
}
digitalWrite(RED_LED, HIGH);
digitalWrite(GREEN_LED, LOW);
}
void setup()
{
pinMode(RED_LED, OUTPUT);
pinMode(GREEN_LED, OUTPUT);
pinMode(BOARD_LED, OUTPUT);
//Timer2 Settings: Timer Prescaler /64,
TCCR2A |= (1<<CS22);
TCCR2A &= ~((1<<CS21) | (1<<CS20));
// Use normal mode
TCCR2A &= ~((1<<WGM21) | (1<<WGM20));
// Use internal clock - external clock not used in Arduino
ASSR |= (0<<AS2);
//Timer2 Overflow Interrupt Enable
TIMSK2 |= (1<<TOIE2) | (0<<OCIE2A);
RESET_TIMER2;
sei();
startup();
}
void loop()
{
if(stepStack)
{
// Toggle the LED
led13 ^= 1;
digitalWrite(13, led13);
seconds ++;
stepStack--;
}
if( seconds > NIGHT_TIME )
{
digitalWrite(RED_LED, LOW);
digitalWrite(GREEN_LED, HIGH);
}
}
