Recent content by mishobg12

  1. M

    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    what I meant was I am NOT a professional :) high frequencies and active components have always been hard for me. I am not good with advanced math, maybe it's because of that. I'm focusing on digital electronics, but you always need to have some active components... Since electronics books in...
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    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    hey, I am a student. berkeman thank you for answering. I think I got it.
  3. M

    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    They are not latched. It really is very simple communication, because all of the work is done by the display itself. So do I think I should put at least a capacitor in parallel to the input. And if yes, what value would you suggest? I found what you said interesting, though...
  4. M

    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    They are slow.. The signal only changes when the location (or direction) of the lift changes. De facto, the minimum time in which the signal will not change is equal to the time in which the elevator travels trough one stop. This usually is as much as 4 seconds.
  5. M

    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    power is 19V stabilized to 5 with 7805 circuit. I was planning just to use my best bet on the prototype and install it on a real elevator. Since it's a digital circuit it can't be that sensitive, right?
  6. M

    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    My device is an elevator display. One UTP cable has 4 twisted pairs = eight cables. every cable is connected to one of my inputs. They have a 5-bit binary number - a code for the respective symbol that should be displayed. The other tree are for the direction. There might be only one display, or...
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    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    Thanks for your answer, berkeman. There is a problem, though. I guess I should have said that the communication is parallel. This does NOT depend on my device.
  8. M

    Safeguarding UTP Cables in Elevator Shafts: Filtering Options

    Hi, I am making a device with 8 INPUTs that will be connected to a long (5-25m) UTP cable running trough an elevator shaft (some interference, I imagine). Could you propose what kind of filters should I use on my inputs. The thing is, the HIGH level on these cables will be 12 to 19V but I need...
  9. M

    Changing Controller from PIC 16f628A to 16f87 - Help Needed

    After testing and debugging all day yesterday I finally figured out what the problem was today. My ports work just fine, but their state depends of what is read from the EEPROM and obviously EEADR, EEDATA and EECON1 are in different banks. Phew, I should have guessed way earlier. Thank you for...
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    Changing Controller from PIC 16f628A to 16f87 - Help Needed

    I needed more EEPROM so I decided to change the controller. I don't seem to be able to use at lest PORTB<0-3> for I/O on the new controller. I understand they can be configured to be used for serial communication and I used the following instructions trying to make them I/O ports: bcf T1CON...
  11. M

    What could be causing the unusual issue with PIC16f628a?

    I am familiar with them. But until then I did not know that RB4 can be used only if LVP is disabled trough a configuration bit as you suggested. So adding _LVP_OFF to my _CONFIGURE line fixed this for me. Thank you very much again and all the best.
  12. M

    What could be causing the unusual issue with PIC16f628a?

    Thank you for the answer! As you can see from here: http://lh6.ggpht.com/adascalitei.victor/SID6E7WqNPI/AAAAAAAABGw/aFRGd0Ed_pQ/s800/pic16f628apinoutdip18.gif the only thing that it could be other than I/O is PGM (used to enable low voltage programming). What can I be configuring about it?
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    What could be causing the unusual issue with PIC16f628a?

    Hi, So I have this strange issue with 16f628a. If I connect RB4 it to +5V, everything hangs, all ports go to 0. It does that no matter whether it is set to input or output. My program is very complex, so to make sure that it is not because of a logical mistake, I tried with this simple...
  14. M

    Switching a PIC circuit from 5 to 12 volts

    Thank you, MATLABdude. You've been very helpful.
  15. M

    Switching a PIC circuit from 5 to 12 volts

    Thank you for answering. I am sorry I didn't explain well enough in my original post. So as far as I understood, I keep everything the way it was when I was powering the circuit from USB, just add this voltage regulator to the power supply line to make it 5V. And the capacitors I should put...
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