Satellite circuit

Discussion in 'Off-Topic' started by Robin Mitchell, Dec 19, 2010.

  1. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
    732
    199
    Hi everyone,

    I got bored, so i designed this XD:

    Im designing a device that is a payload on a rocket. The rocket goes as high and far as it can, releases the payload and then the payload hits the ground. Then the little BEAM bot inside goes for a wonder for the rest of its life. But the cool part is that it transmits data about its surroundings using a very crude system of 555's, counters, binary and radio.

    The sensors consist of an LDR and Thermistor. They connect to their own 555 astable timer circuit. Depending on the resistances of these it changes the frequency of the 555's. They connect to a binary counter so it crudely converts them to four bit numbers. The main clock will stop the counters from counting and then enables another counter. This then goes through a system which converts the parallel 8 bit data into single pulses.

    Two radio signals are sent, a start clock and the data.
    So i get this:
    Code ( (Unknown Language)):
    1.  
    2. Start clock: 10000000
    3. Data       : 10110101
    4.  
    Now, the data gets split up into two four bit numbers, 1011 and 0101
    This is the data recorded by the counters and i can tell from the pulses what the temp and light intensity is like....

    So looking at those two numbers i can say that it is Bright and quite hot!

    What do you think?
    Also the simulation works!

    [​IMG]

    Uploaded with ImageShack.us

    [​IMG]

    Uploaded with ImageShack.us

    FOrgot to change that it needs to send 9 pulses so the last pulse resets the shift registers on the reciver.
     
    Last edited: Dec 19, 2010
  2. tom66

    Senior Member

    May 9, 2009
    2,613
    213
    Uh... it's one way to do it! I like it, very creative, but it could all be put on to a single microcontroller. A 16F PIC would probably be enough. I think you're going to struggle to fit that on a small rocket.

    (My Super OSD project does this, it can be equipped with a video transmitter and beam video down (with telemetry), while datalogging to the 2 megabyte serial flash.) While it's designed for model aircraft, there's nothing stopping you using it on a rocket, or any other vehicle, for that matter, although it is only rated for -40°C to +85°C. The on board precision (±0.5°C) temperature sensor can sense the outside air temperature, and with a resistor and using the onboard 3.3V 400mA switching power supply (4.8V - 30V input), an LDR can be used to measure light levels (it has 6 analog inputs, 3x 0-3V and 3x 0-30V.)
     
  3. maxpower097

    Well-Known Member

    Feb 20, 2009
    795
    388
    .......................................................
     
    Last edited: Jan 16, 2011
  4. thatoneguy

    AAC Fanatic!

    Feb 19, 2009
    6,357
    718
    I'd also suggest a PIC for this. The nanopower series is great for these sort of projects, where it can sleep/charge using almost no current, then wake up and move around. The 555s and logic would be a rather heavy draw for small batteries.

    That said, it's a Very Cool Project idea!
     
  5. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
    732
    199
    wow thanks guys XD

    I wanted to do something without pics, i have NO idea how to use them :p
    I could fit this on a small board if i use a few SMD.

    Its my equivelent of sputnik, a device made from simple chips that can send data, never worked with radio waves before :p
     
  6. tom66

    Senior Member

    May 9, 2009
    2,613
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    PICs are quite simple. Go and buy yourself a PICkit 2 or 3 starter kit and follow the tutorials on the CD - it's quite easy once you get the basics, and they teach you in assembly and C.

    If you're an AVR person you also have Arduino.
     
  7. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
    732
    199
    what abou c++? can you use that as i know c++

    Also tom, who said it would be a small rocket ;)
     
    Last edited: Dec 20, 2010
  8. tom66

    Senior Member

    May 9, 2009
    2,613
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    C++ is just an extension of C. Generally, you only use C on microcontrollers, because they are resource limited. You can stick to using C++ as long as you don't use classes, templates or other C++ features.

    Even with a big rocket you will struggle to all of those ICs on it. Are you going surface mount or through hole?
     
  9. Robin Mitchell

    Thread Starter Well-Known Member

    Oct 25, 2009
    732
    199
    neither im going to use magic :p

    Well if I use DIPs on a board the circuit will fit on a 2.5 by 3 inch board, tiny i know :p
    This thing will not fit on a rocket, that was just an idea. The "thing" that delivers the payload is secret and no details will be released on that!

    But the "thing" can easily deliver it! I can assure you :)
    But microcontroller kits look very expensive :(.
    Could you give me some online tutorial links please please please :)
     
  10. tom66

    Senior Member

    May 9, 2009
    2,613
    213
    Super OSD (open source - see it here: http://code.google.com/p/super-osd) fits in 41mm x 61mm, and will probably be smaller in later versions. It will retail for about £40-£50.

    If you want a kit, get a PICkit 3 debug express for ~£45:

    http://www.microchipdirect.com/productsearch.aspx?Keywords=DV164131

    If you want to spend less, then a PICkit 2 debug express is also available for ~£30, but it is an older version and you can't program some of the newer micros with PICkit 2:

    http://www.microchipdirect.com/productsearch.aspx?Keywords=DV164120

    If you need some more help with microcontrollers I'd be happy to help. The tutorials that came with these gave me all I needed to know.
     
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