Advice on how to make LED circuit with date based timer

Discussion in 'The Projects Forum' started by Todd M, Oct 6, 2014.

  1. Todd M

    Thread Starter New Member

    Oct 6, 2014
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    0
    Hello everyone!

    I am new to the forum and am looking for advice on how to start a project. I want to make an LED circuit where I can input a date (e.g. Oct 7th). I then would like to the lights to turn on for 24hrs beginning on that date. Ideally I would like to have a user friendly interface for inputting the date. Any ideas for this project would be greatly appreciated!

    Thanks in advance.
     
  2. MrChips

    Moderator

    Oct 2, 2009
    12,442
    3,361
    The obvious solution is to use a microcontroller (MCU). How much knowledge and experience do you have with MCU?
    Besides knowing the alarm date the system would have to know the current date and time and would have to keep track of time, i.e. a time of day clock function is required.

    A viable solution would be to use an Arduino with an LCD.
     
  3. wayneh

    Expert

    Sep 9, 2010
    12,123
    3,048
    You might simplify things by using a smartphone for interacting with the MCU to set the date. That would free you from having to incorporate an LCD and a human interface. Of course that trades for writing an app and adding a bluetooth module.
     
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    What is the fineness of the selected time, one day, day & hour, or finer? How far into the future will time be selected, a few momths or more?
    If for some reason that a non MCU approach is desired, then a string of BCD counters, hand full of Digital comparators & some BCD thumb wheel switches might do.
     
  5. Todd M

    Thread Starter New Member

    Oct 6, 2014
    2
    0
    Thank you for all the responses and advice. As for the fineness of time I would like to be able to select a certain day months in advance.
     
  6. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    For the uC uninitiated, me, start with a 1 day clock, 3 BCD counters, 3 74C85 comparators, & 3 BCD thumb wheel switches, hundreds of hours, tens of hours & units hours. As the selected time flys by, the comp. will will give an output when hours agree, which then sets a flip-flop, which starts a 24 h counter, 4960, & turns on "the lights". End of 24 h, FF re set, day clock inhibited, lights out.
    To input, take out calculator & add up the days & input on SWs, might take 2 min.
     
  7. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    4,770
    970
    arduino board + timer/TimeAlarms library + resistor + led = done :)
    depending on what this LED is it might need a transistor or mosfet or relay to switch it on/off
    http://playground.arduino.cc/Code/Time
    Just the arduino alone will "worst case" only loose 30 seconds a day..
    if you need more accuracy just add a RTC clock chip..
     
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