Displaying time

Hi, I’ve incorporated the following sketch to my aquarium LED lights and it works fine, but i also want to display the time on a 16x2 lcd display. Can anyone help with the code? I am an idiot with codes…

Thanks :slight_smile:

// Pins to control LEDs. Change these if you're using different pins.
int blueLed = 9;     // LED PWM channel for blues
int whiteLed = 10;   // LED PWM channel for whites

// Set up RTC
#include "Wire.h"
#define DS1307_I2C_ADDRESS 0x68

// RTC variables
byte second, rtcMins, oldMins, rtcHrs, oldHrs, dayOfWeek, dayOfMonth, month, year;

// Other variables. These control the behavior of lighting. Change these to customize behavoir
int minCounter = 0;         // counter that resets at midnight. Don't change this.
int blueStartMins = 1410;    // minute to start blues. Change this to the number of minutes past
                            //    midnight you want the blues to start.
int whiteStartMins = 1409;   // minute to start whites. Same as above.
int bluePhotoPeriod = 10;  // photoperiod in minutes, blues. Change this to alter the total
                            //    photoperiod for blues.
int whitePhotoPeriod = 10; // photoperiod in minutes, whites. Same as above.
int fadeDuration = 5;      // duration of the fade on and off for sunrise and sunset. Change
                            //    this to alter how long the fade lasts.
int blueMax = 50;          // max intensity for blues. Change if you want to limit max intensity.
int whiteMax = 255;         // max intensity for whites. Same as above.

/****** LED Functions ******/
//function to set LED brightness according to time of day
//function has three equal phases - ramp up, hold, and ramp down
void setLed(int mins,    // current time in minutes
            int ledPin,  // pin for this channel of LEDs
            int start,   // start time for this channel of LEDs
            int period,  // photoperiod for this channel of LEDs
            int fade,    // fade duration for this channel of LEDs
            int ledMax   // max value for this channel
            )  {
  if (mins > start && mins <= start + fade)  {
    analogWrite(ledPin, map(mins - start, 0, fade, 0, ledMax));
    if (mins > start + period && mins <= start + period - fade)  {
    analogWrite(ledPin, ledMax);
    if (mins > start + period - fade && mins <= start + period)  {
    analogWrite(ledPin, map(mins - start + period - fade, 0, fade, ledMax, 0));

/***** RTC Functions *******/
// 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) );

// 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 setDateDs1307(byte second,        // 0-59
                   byte minute,        // 0-59
                   byte hour,          // 1-23
                   byte dayOfWeek,     // 1-7
                   byte dayOfMonth,    // 1-28/29/30/31
                   byte month,         // 1-12
                   byte year)          // 0-99

// Gets the date and time from the ds1307
void getDateDs1307(byte *second,
          byte *minute,
          byte *hour,
          byte *dayOfWeek,
          byte *dayOfMonth,
          byte *month,
          byte *year)

  Wire.requestFrom(DS1307_I2C_ADDRESS, 7);

  *second     = bcdToDec(Wire.receive() & 0x7f);
  *minute     = bcdToDec(Wire.receive());
  *hour       = bcdToDec(Wire.receive() & 0x3f);
  *dayOfWeek  = bcdToDec(Wire.receive());
  *dayOfMonth = bcdToDec(Wire.receive());
  *month      = bcdToDec(Wire.receive());
  *year       = bcdToDec(Wire.receive());

void setup()  { 
// init I2C  

/***** Main Loop ***********/
void loop()  { 
  // get time from RTC and put in hrs and mins variables
  getDateDs1307(&second, &rtcMins, &rtcHrs, &dayOfWeek, &dayOfMonth, &month, &year);
  minCounter = rtcHrs * 60 + rtcMins;

  // determine if it is day or night, and act accordingly
  if ((minCounter > blueStartMins || minCounter > whiteStartMins)
           && (minCounter < blueStartMins + bluePhotoPeriod || minCounter < whiteStartMins + whitePhotoPeriod))  {   //day
    // set LED states
    setLed(minCounter, blueLed, blueStartMins, bluePhotoPeriod, fadeDuration, blueMax);
    setLed(minCounter, whiteLed, whiteStartMins, whitePhotoPeriod, fadeDuration, whiteMax);
  else  {   //night
    analogWrite(blueLed, 0);
    analogWrite(whiteLed, 0);
  // Get ready for next iteration of loop

does this http://www.arduino.cc/en/Tutorial/LCDLibrary help?


It does, thanks. I'll read through it and try to come up with a simple code to display the time and later on temperature.

Thanks for the link :)

Hi everyone,

I want use this sketch to my LED Lamp, but I thinking about some keys, switchs by which one I can settings the some options, like start and stop of lighting, delay time for fade, intensity of light etc. it is possible ?


it is possible ?

Of course it is. You’ll need to add external hardware - switches and/or a keypad, and a bunch more code display a menu and enter programming mode, etc.

Add one function at a time, and thoroughly debug that, before proceeding to the next function.

For instance, you’ll need a way to display the menu choices. So, add an LCD, and learn how to write to that.

Then, add switches to show a menu, and cycle through the options, and exit the menu, without being able to select any options.

Then, add a switch to actually select an option. Add functions for each option that can be selected.

Make one option work before writing code for the next option.

I think, that i make some difrent, that I build some interface in c# and contact with arduino by serial port ;) and set some verialbles like I want.