Burgalar Alarm System

Discussion in 'Homework Help' started by wardyyboyy, Nov 20, 2008.

  1. wardyyboyy

    Thread Starter New Member

    Nov 20, 2008
    im close to starting my circuit making for my final GCSE project in systems and control
    and i need help, i have my basic circuit for my design with a keypad LED, PICAXE and a piezo sounder, the system will sound an alarm when a connection between a reed switch is broken and not stop untill the 4 digit code is entered, this code will then show up in an LCD screen
    but now i need help, first problem:

    I need to use and LCD screen bu i dont know how i would go about attaching one, i think i have an i dea but im not entirely sure, would i connect a pin from the pic chip to the data pin on a shift register then a pin to the data clock then from the S/R to the R/S, D0 and D1 of the lcd screen and one from he pic straight to the LCD like in the link below? but then for his i would need o alter my design for a a bigger pic chip
    or would i go about it a different way?

    Second Problem:
    I need also to connect a reed switch is this as simple as any other switch? if so what resistor would i use? wold i just connect to a pin on the pic hip then to the positive rail with a 10kΩ resistor? or smaller?

    Third Problem:
    I would then also need to make a flow chart for my system but making them is not my strong point so could some one 'point me in the right direction' so to say?:p
  2. Bernard

    AAC Fanatic!

    Aug 7, 2008
    You have 3 normally closed reeds in parallel, so all 3 would have to be activated to get an output,put them in series.Resistors should be on otter side of switches.
    Last edited: Nov 20, 2008