remote controlled sequential switch

Discussion in 'The Projects Forum' started by electronoob, Apr 12, 2010.

  1. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    hey guys
    im trying to make a remote controlled sequential switch but i need some help because i don't have any experience in electronics
    im trying to make a circuit for a rc plane so that i can control all the light with only one switch

    i was thinking about using this ic (http://www.datasheetcatalog.org/datasheets/320/499984_DS.pdf) for the switching but i have no idea how i can change a standard receiver output into something i can use
    the receiver has 3 wires +6volt -6volt and a square wave (between 1-2ms)
     
  2. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Welcome
    what type of experience do you have concerning electronics and transmitters
    Tell us about ur self first
     
  3. Bychon

    Member

    Mar 12, 2010
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    One or two milliseconds is easily within range of the 4017 chip, but we'll need to know both voltages of the square wave and if it's "clean". If you can measure milliseconds, that suggests you have an oscilloscope. True?

    It is very likely we can make something the 4017 chip can listen to. The question is, Can you build circuits?
     
  4. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    im dominique i live in belgium im 20 years old im studying to become a pilot
    i have been flying model planes for over 6 years now
    i have a basic understanding of electronics (i studied advanced physics in high school) i have made circuits before but then i had drawings (so i didn't really know what the exact function of each component was, i just replicated the drawing)

    i don't have an oscilloscope but i know its a square wave because thats what model airplane receiver put out and thats what servos respond to

    this chip can transfer the signal to something i can use
    http://www.rc-cam.com/bitsw.htm
    but how can i program a ic
     
  5. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Nice little chip.
    For this job you should learn MPAB IDE, student version is free, and fully functional.
    Just google it you will find it.
    Learn how to program these and then you can make what u want.
     
  6. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    i don't need to write the program. the program is already on the site
    i just need a way to put the program on the chip

    can you solder chips that are that small, won't the heat damage the chip ?

    can i connect the output of the pic10f202 directly to the input cd4017bc
     
  7. Markd77

    Senior Member

    Sep 7, 2009
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    I think it might work.
    The reciever pulse is a 1-2ms high every ~20ms dependant on the transmitter stick position. The programmed 10f202 converts that to a continuous high output if the stick is above a certain position (pulse greater than 1.65ms). With a 5V supply to both the output of the PIC would be in the input range of the 4017 so that should change to the next light every time the stick is moved up and down. The output current of the 4017 is very low and unsuitable for powering lights directly.
    To program the PIC you would need something like a PICKIT2 (or clone) which would dominate the price of the project.
    Soldering the little chips takes a little practice (look for videos on youtube) and you would have to make your own PCB. Or just get the normal sized 8 pin version if you can afford the space.
    Someone might come up with a way to convert the pulses to something usable without the PIC but that is beyond my ken.
     
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  8. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    thanx for the help
    im considering making my own pcb do you know a good program to draw the pcb or do you just use ms paint
    is the output of the 4017 enough to power a relays or do i need a mosfet between the output and the relays (i need a relay anyway because im running my lights of a different batery)
    are they that expensive ? will this do the job ?(pic10f isn't mentioned in the discription) http://cgi.ebay.com/DIY-USB-PICKIT2...lectrical_Equipment_Tools?hash=item5ad635d602
    i guess i have to make a small circuit to connect the ic with the pickit? like in this picture http://www.electronics-lab.com/blog...graming-socket-for-the-pickit-2-programer.jpg

    it looks like the hardest pert of the entire build will be getting the program on the chip
    are there chips like the pic10f202 who already have the correct program installed
     
  9. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
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    Your nuts if your buying a pickit2 KIT from hong kong for $38.

    I would have a HARD time being convinced that it is OEM goods.

    Take a look at what there selling you for $39 from hong kong that you have to build yourself:
    [​IMG]

    And from Microchip for $35, its REAL and you dont have to build it, and you get a WARRANTY :
    [​IMG]

    Notice the HUGE differences in the images.

    If you want, get the pickit2 starters kit, includes cables, software and demo board and a pic to get you going for $49.99
    http://www.microchipdirect.com/productsearch.aspx?Keywords=DV164120
     
  10. Markd77

    Senior Member

    Sep 7, 2009
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    Well they are not that expensive, but I was just saying that it would probably cost more than all the other parts. Once you have one you might find more uses for it.
    4017 will not power relays. Have a look at the specs of the ULN2803 which can switch higher voltages and might replace the relays.
    I don't have much experience making PCBs, the only ones I've done have been with etch resist pens, which might be suitable if you are only making 1.
     
  11. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    correct my if im wrong
    a uln 2803 would replace relays, i plug the output of the cd4017bc into the uln 2803 it would amplify the current to power the lights but that means that the battery of the receiver would power my lights ?

    can i etch a pcb by drawing the lines on the coper with a permanent marker and then dipping the plate in Sodium persulfate (will the permanent marker protect the coper against the acid)
     
  12. electronoob

    Thread Starter New Member

    Apr 12, 2010
    11
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    i made a drawing about how it think it should fit together
    any thoughts or remarks (bear in mind that i have never designed a circuit before so it might be completely wrong)


    [​IMG]

    those things on the right side are mosfets i guess i will eventually go for the uln2803 im not sure yet
     
  13. Markd77

    Senior Member

    Sep 7, 2009
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    I think this might work. I'm not too good on 4017 chips so I might be missing something.
    On a side note if you used a larger (14 pin) PIC and programmed it right you wouldn't need the 4017 but maybe that is for another project.
    <edit> In fact I think this PIC could handle 3 outputs and 1 input and the 12F675 with 8 pins should be more than capable, but the program would have to be rewritten </edit>

    [​IMG]
     
    Last edited: Apr 15, 2010
  14. retched

    AAC Fanatic!

    Dec 5, 2009
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    And yes, the proper Sharpie or specifically formulated marker will RESIST the etching checmicals. For Ferric Chloride and Peroxide/Muritac Acid resisting it works.. As for Sodium Persulfate, I am not 100% sure. The industrial uses Sharpie works well. SgtWookie has a pen that works well for him.. But the name of which escapes me.
     
  15. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    0
    thanx for the info mark
    the receiver ground is that the same thing as the negative servo lead
    why do i need the 3 capacitors couldn't i replace them with 1
    also do i have to connect clock enable to vss or can i connect it directly to the ground
    im going to try that after i have successively build my first one
    im buying my ic on ebay so ill have alot of spare ic

    edit
    correct my if im wrong
    a uln 2803 would replace relays, i plug the output of the cd4017bc into the uln 2803 it would amplify the current to power the lights but that means that the battery of the receiver would power my lights ?
    can a rc receiver handle those types of currents,?
     
    Last edited: Apr 15, 2010
  16. Markd77

    Senior Member

    Sep 7, 2009
    2,803
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    Yes
    Logic chips like small capacitors as close to them as possible to stop voltage spikes interfering with their operation. The other one is to reduce the effect that this circuit has on the rest of the plane and vice versa.
    Either is fine.
    The 2803 outputs can connect through your lamps to a seperate positive supply, with the grounds (negative wires) connected together so the reciever isn't powering the lamps. The 2803 pin connected to the internal diodes can be connected to the lamp positive power supply.
     
  17. electronoob

    Thread Starter New Member

    Apr 12, 2010
    11
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    al the parts arrived today
    the pic 10 is really tinny can i solder wires to it so that i can mount it to a standart testing board
    also can i program it while its already in the circuit
     
  18. retched

    AAC Fanatic!

    Dec 5, 2009
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    I wouldn't try soldering wires to the pic, unless you have quite a talent for soldering.

    A little to hot, and the PIC is toast.

    See if you can get a socket that can accept the chip, or a surfboard-type adapter.

    This allows you to use a solder paste and just sliding your iron over top to connect it to the adapter that can be used in a bread board.

    Nex time you order, get DIP or P-DIP packaging. You probably got a surface mount version. Not easy for beginners.
     
  19. electronoob

    Thread Starter New Member

    Apr 12, 2010
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    0
    is there some type of conducting glue i can use to connect wires to the pic so i don't risk overheating it

    could i use the program of the pic10f202 on the the pic10f204
     
  20. Markd77

    Senior Member

    Sep 7, 2009
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    I think the 204 will work the same with the exception of the comparitor. If you put a line near the start:
    bcf CMCON0, CMPON
    I think that should take care of it.
     
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