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coding using pic 16f877a with tsop4p38(proximity sensor)

Discussion in 'Microcontrollers' started by ripingz, Feb 18, 2012.

  1. ripingz

    ripingz New Member

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    View attachment 61278 as you can see...this tsop4p38 volt supply using 3v dc right???? not 5 volt right??but the pic using the 5 volt....i had constructed my power supply already ...if you say yes to this question....i just need parallel it more to get 1 more out using lm7803...:p

    look at this attachment sir john View attachment 61280 is this valued as 0.001u or 0.01 u?
     
    Last edited: Feb 20, 2012
  2. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    0.001 µF

    John
     
  3. ripingz

    ripingz New Member

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    i will keep in touch with this forum sir john.... if i already make the project...i will upload the photo
     
  4. dave

    Dave New Member

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  5. ripingz

    ripingz New Member

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    but what i can see from the circuit..all the resistor using 5 percent of tolerance...are i have to parallel it all???? or just resistor r2 only???
     
    Last edited: Feb 20, 2012
  6. ripingz

    ripingz New Member

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    i have understood now about my question here... :p
     
  7. ripingz

    ripingz New Member

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    i had constructed my pcb for this circuit...but it doesnt work..no output at all....this is the scematic View attachment 62605

    is this circuit had got any problem.....( solved = the d1 diode ...cathode is connected to trigger pin 2 of timer555 )...tomorrow i will tested it with 9v of batt....can i use 9v batt????.....i dont want to use combined battery of AAA & AA size battery
     
    Last edited: Mar 24, 2012
  8. ripingz

    ripingz New Member

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    john help me ~~~
     
  9. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    You don't have trigger connected to anything in U1.

    John
     
  10. ripingz

    ripingz New Member

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    i want to know...why the input dc voltage such as 7v...will make the output ir voltage will become 6v-7v.... if the output voltage of the ir is 7volt.....can it compatible to make the receiver to respond....(please i want to know this)
    i have solved the problem i had mentioned before...this the problem.... as in the picture in red line i had sketch... (reminded that the r7 value is 2k ohm and the r3 is 12k ohm.) View attachment 62913
    the problem is..... the output waveform althought the output voltage is around 4.7volt . i'm using the 6v batt. and the output volt at the ir is around 4.7 volt....and i had try to see its output...and this is the record i got from digital oscilloscope...as below:

    frequency:6.476khz
    period:154.4us
    mean: -4.68v
    peak to peak:4.96v
    rms: 4.69v
    min: -4.88 v
    max" 80.0mv...

    as in the record...the frequency i should get is in 38khz to 40 khz....and the period time should in 100 ms.....what should i do.. the receiver can't detect this kind of signal... if i got make the two device interface..surely i can make the program by my self :( as in this datasheet.... View attachment 62914
     
    Last edited: Apr 3, 2012
  11. ripingz

    ripingz New Member

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    can this modified circuit get deserved output??? please correct me if i was wrong.. i wanted to use the 9v battery View attachment 62957
     
    Last edited: Apr 3, 2012
  12. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    I am not sure I catch all of your questions.

    1) Voltage output versus input: Check the datasheet. The 555 you are using is not CMOS and cannot swing its output to the power rails. Thus, the max output voltage is approximately Vcc-1.7V at 100 mA. That voltage drop increases slightly at higher currents. That is all explained under "Electrical Characteristics." For the LM555, the output voltages are described on page 4 of its datasheet.

    2) Frequency: The 555 is a robust device and is relatively stable. However, the frequency of this circuit will vary with the supply voltage. (Note, there are diode voltage drops introduced, not just resistors.) What voltage do you intend to use? I did the spice model at 5V for the reasons stated in that post. Now it seems you have tried some other voltages. Pick just one voltage that you want to use. Let's get it working at that voltage. Then, if you want to change the voltage, you will have a starting point to know what will need to be adjusted.

    3) The higher frequency oscillator in the asc file you attached is oscillating at 46 KHz in simulation. That is probably due to the voltage used. See #2, above. When you reference a specific frequency, is that measured on a prototype or from the simulation?

    John
     
  13. ripingz

    ripingz New Member

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    i wanted to use the 9v of battery....it is more easy to plug it also....i dont want to use AAA battery....the record measurement is what i get from the digital oscilloscope...i dont know why the reading slightly big different....and the receiver does not respond due to the transmitter....i know it because i have put the oscilloscope probe at the receiver...it doest not working...the sensor is confirmly ok....but the transmitter is the problem
     
    Last edited: Apr 4, 2012
  14. ripingz

    ripingz New Member

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    the output voltage is varies the input voltage.....same with frequency..the higher input voltage..the higher frequency obtained..... but now im using battery....how i'm gonna to make it constant frequency :(
     
  15. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    Your 9V battery will not have much current capability nor last very long. Are you sure that is what you want to use?

    John
     
    Last edited: Apr 4, 2012
  16. ripingz

    ripingz New Member

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    i dont know if this is the right choice to choose....i want the transmitter sized as big as a cigarette box....so what did u suggest to me....
     
    Last edited: Apr 4, 2012
  17. ripingz

    ripingz New Member

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    i got confused here....there is one resistor u ask me to parallel...but im not parallel it...my lecturer said to me that i doesnt necessary parallel it.... and my circuit is contructed serial like this View attachment 62970 .... is this ok to produce the desired output for the tsop4p38 ??? and if i want to parallel it..i have to use two valued 22k resistor with 5 %.... ( is this okay???? because the rn i got is 11k)... like this image View attachment 62971 ....so which must i choose between this ...are there any different between this two kind of assembling....it must be affecting the time in us....maybe...i dont know if i was true
     
  18. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    Assuming you can fill that size half with batteries, there are lots of choices. Consider any of the lithium chemistries, NiCd or NiMH. Lithium-based batteries are usually 3.2V (nominal) per cell; Ni-based are 1.2V per cell. Fresh batteries give higher voltages than that. Thus 2 lithium batteries with a low-drop out voltage regulator will give a pretty constant 5.0 V. Regular alkaline/carbon batteries can also be used at 1.5 V each. You could also use a regulated wall wart.

    You might want to consider driving the oscillators and receiver from a regulated supply and using a transistor to power the IRED from an unregulated supply -- same battery, just no regulator. Since you are including an MCU in this project, you will probably have a regulated voltage anyway.

    I have absolutely no idea what resources you have available, so the choice of battery/supply has to be yours. Remember, rechargeable batteries need chargers.

    John
     
  19. ripingz

    ripingz New Member

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    ok.... i think i will supply my transmiiter with a 12v batt....and then i will constructed a power supply circuit...which is i have....and then make it to 5v....
    i want to ask earlier post...about the resistor connection that i had mention in #56 post....
     
  20. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    A 2K plus 12K resistor gives 14K too. But, if your instructor told you to put the 2K right after the source, that was wrong, as it will affect the frequency of both oscillators if placed there.

    Keep in mind that if you need 14K, it doesn't really matter how you get it. You can use any of a variety of parallel resistors, series resistors, combinations of parallel and series resistors, or a potentiometer without or without a fixed resistor. I recommend getting the project to work first. Then worry about the resistors you are going to use.

    John
     
  21. jpanhalt

    jpanhalt Well-Known Member Most Helpful Member

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    Just to clarify: Do you want the transmitter to run on unregulated 12V, regulated 12V, or regulated 5V produced by a 12V battery?

    John
     

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