Alarm Clock System!

Discussion in 'The Projects Forum' started by Gravesen16, Nov 12, 2009.

  1. Gravesen16

    Thread Starter New Member

    Nov 12, 2009

    I'm new to the site! My name is Steven, and I'm currently studying at HNC level. However we have been given a project and for this we have to design a unique Alarm System. We have chosen to do an alarm that can be set manually, then will be de-activated when a pressure pad (from under the mattress) is released. This means that the user will have to be out of bed for the alarm to be de-activated, another idea was to have a detector between the bedroom door and door-frame, meaning the user will have to open his bedroom door to de-activate it.

    However, I have been tasked with creating the circuit on bread board layout. Any help you could give me would be very much appreciated, as I am a total amateur in this field although circuit design is something I would like to gain a lot of knowledge in.

    Thanks very much, hope to hear from you all soon. :)
  2. MaxSmoke

    Active Member

    Oct 29, 2009
    Hello and welcome to the forum :)

    Cannot see why you need the alarm, surely you jump up every morning at 05:30 hours bright eyed & bushy tailed :D

    Your idea of using a door switch is good, but consider deactivating the alarm on a change of state. In other words, if the door is left open or shut it does not matter, to deactivate the alarm you have to close or open the door. This is easy, as the state of the door switch is latched by your circuit (or software), just before the alarm activates. This way the door can be opened and closed as many times as you like without affecting the alarm circuit.

    I guess you are planning to build the clock as well, you can either use a RTC (Real Time Clock) chip or a micro controller that contains an RTC, already built in to the device. There are many chips to choose from, for example Microchip have a large range of controllers - PICs, then the is ST Microelectronics, plus many more. This requires you learning C or the microcontrollers assembler.

    Another option is an RTC chip hooked up to a programmable logic chip, like a small FPGA or possibly a CPLD. This may require you learning Verilog or VHDL, although I think many of the FPGA vendors development tools do allow schematic capture, but it is better to use a high level design language.

    Draw a block diagram with of the alarm clock system and then design the circuit for each block. For a circuit like this battery powered is the way to go.
  3. Sutitan

    New Member

    Nov 12, 2009
  4. SteWonk

    New Member

    Nov 11, 2009
    Hi, this is Steven.. My last e-mail account was wiped so I'm on a new username :)

    The alarm clock circuit is acceptable to be bought from somewhere, so I was thinking Maplin or something. Then I will need to incorporate the pressure pad system, or your much more interesting door open/close system. Although I have no idea how to do this! I can solder etc. but am completely new to this world of circuit design!

    I appreciate all the help, and hopefully you can keep patience and continue to help a confused young man!