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light sensor switch...good book for dummies? — Parallax Forums

light sensor switch...good book for dummies?

markmcleod50markmcleod50 Posts: 27
edited 2004-10-26 21:18 in General Discussion
I am new to electronics and am looking for something that could be used as a somewhat programmable light sensor switch. The parts must fit inside a small toy slot car. I am using two conductor tape to supply power to the cars tiny motor, 3 volts from a wall transformer. I would like to tap off of this power to run the light sensor amd headlights/music so as to not have to run more conductor tape/wire. The car will always travel along the track, but when its sunny, the car plays music, when its cloudy, the headlights turn on, never both at the same time but always one will be on. I don't know if their is a light sensor that can act as a switch or a grouping of parts I could make do what I want. I do have a basic stamp, but the size and powering it is an issue. It's important to have the light sensor, headlights, music to run off of the motors the same power as the motots and not a seperate battery inside the car.

What part or parts do I need for a light sensor switch?
What part might I need for a simple music recorder that would repeat the music over and over?
Any other parts I may need?
Any good books on electronics for dummies, like myself?

Thanks for all the help. Mark

Comments

  • Jonny555Jonny555 Posts: 46
    edited 2004-10-19 20:09
    Everything you mention is pretty straightforward.

    You need:

    photocell
    capacitor
    a few resistors
    2 X Bright white LED
    Piezo speaker

    Suitable 5V power: you can't use 3v for the basic stamp without boosting the voltage to 5v.

    Build a light sensor(look in parallax website its there)
    Use DTMF to output tones to piezo.
    LED's are a joke.


    This is a 30 minute project.· Will the BS2 fit into a slot car?


    Jon

    Post Edited (Jonny555) : 10/19/2004 8:12:48 PM GMT
  • markmcleod50markmcleod50 Posts: 27
    edited 2004-10-19 21:57
    whats dtmf? and no the bs2p40 board will not fit, so I was trying to think of alternatives like a simple small circuit that I could leave in the car...this is a sculpture project that will travel to other galleries, are oem models of basic stamp just as easy to use and hook up as the bsp40?
  • Jonny555Jonny555 Posts: 46
    edited 2004-10-20 17:54
    DTMF is telephone tones [noparse]:)[/noparse]

    From Webopedia:

    Short for Dual Tone Multi-Frequency, the system used by touch-tone telephones. DTMF assigns a specific frequency (consisting of two separate tones) to each key so that it can easily be identified by a microprocessor.

    Well the oem basic stamps are all inclusive, ready to hook up to a serial cable from your computer for programming. They are however larger then the modules. Depends what you need. I thought of purchasing a oem but realized that i could much more easily incorporate the module to my custom circuits.

    I hesitate to mention the PIC word on this forum, but if the module doesn't fit into the slot car, a custom pic circuit would be an option. Programming pic is not as fast as the basic stamp, and you would need to purchase a special programmer etc. Its a whole other ballgame and an extensive process for the beginner.

    Another post using slot cars suggested passing the signals through the rails but I have no clue if it would work in this case. Whats with people using slot cars...



    Afterthought: Perhaps "hacking" the car by remaking the body a little larger would be suitable by perhaps using the "dead bug" method. "Dead bug" consists of all the circuit components soldered together and stacked instead of placing on a circuit boad. Space saving and weight can be reduced. Either way you've got lots of work to do on your end and theres no easy way. You won't find any dummy books, but do some research and read as much as you can.
    Get your hands dirty and keep plugging tongue.gif

    Post Edited (Jonny555) : 10/20/2004 6:04:50 PM GMT
  • sunktrucksunktruck Posts: 10
    edited 2004-10-26 21:18
    Why not avoid the BS2 all together (will i get in trouble for say that wink.gif ) Use a LM358 comparator/op amp (8pin) have the input voltage be a voltage divider between a photoresistor and a fixed resistor. Have the "comparason" terminal be the center pin of a 100k pot (this would be the programmable part). The output of the LM358 could drive a 2n2222 for the LEDs and also be a "chip select" for an outboard IC that plays a melody (I remember seeing those in my old RS catalogs). I cannot imagine the melody IC would take many external components. The only issue i can see is your 3v limit. Hope this helps
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