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Tell us your favorite PIC project.

Discussion in 'Microcontrollers' started by isaacj, Dec 21, 2002.

  1. isaacj

    isaacj New Member

    Joined:
    Dec 20, 2002
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    Location:
    Mojave Desert
    The first time I used a PIC was for my senior project in college. My teammates and I built an automated logic chip tester/dispenser. A robot arm would pick the chips up from their storage tubes and drop them in a ZIF socket. They were then tested for correct operation. If they passed, they would be dropped on a conveyor belt, if they failed they would be dropped in a bin for disposal. We even added prerecorded messages to tell you if a chip passed or failed.

    So, what's the most fun you've had with a PIC?
     
  2. thec

    thec New Member

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    Location:
    Alvesta, Sweden
    In school I did a project with a basic stamp, programming a memory card (smartcard) through the philips I2C-bus. The bus only has 3 lines - gnd, data and signal. So it was great fun just figuring out how to store the data on the smartcard through a simple interface like that.

    The design was of course a piece of cake, but the programming was the real challange and the project documentation ended up being 16 pages long due to the complexity of the I2C-bus.

    Anyway, I finished the project, put it a side and never used it again. But if you're going to start with a I2C project, I would really, REALLY, recommend to buy a LCD output or something like that first... it was hard to store data and then read it to see if things were right... I mean.. if errorous result came back, were there a problem in save() or load() ? :)

    Of course I did the (mandatory?) blinking lights, running lights, alarm circuits etc with the basic stamp but I was just playing around with it.

    //Albert "thec" Sandberg
     
  3. lavenatti

    lavenatti Member

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    Location:
    Peoples Republic of NJ
    I've built quite a few, most of them test for leaks in disposable medical devices.
     
  4. dave

    Dave New Member

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  5. jessey

    jessey New Member

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    Sep 17, 2003
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    Location:
    Vancouver Island. BC Canada

    My 1st project other than flashing a led.

    Hello, my first project was to modify an inexpensive Wall Mart universal programmable remote control to operate my TV using a 16F84 micro. I call it a 'video announcer' and the system works as follows. I have a motion detector in my driveway and a camcorder connected to the video in of my TV sitting in a window looking at the motion detector in the driveway. The motion detector is hard wired to the 16f84 micro circuit that operates the remote control.

    I took the remote apart and followed the circuit board traces under the remote's power button (previous channel and other buttons that I wanted to activate on the remote) back to the micro that controls the remote and soldered wires to those pins and used the 16f84 to switch transistors to activate those functions.

    When someone pulls into my driveway the 16f84 sounds a buzzer then turns on my TV and switches the TV to the video channel for 18 seconds (it takes my TV about 10 seconds to show a picture when it is first turned on) then it shuts off the TV.

    I made another circuit that is hard wired to the 16f84 which tells the micro if the TV is on or off. This uses a Radio Shack transformer of which I ran the 120 vac through the secondary windings to an ac receptacle that I plug the TV into. When the TV is on it induces a voltage onto the primary windings that is sufficient to light a neon bulb. I used the neon light to activate a simple photo circuit which gives me a positive out when the TV is on.

    If I'm watching the TV when someone walks into my driveway, the 16f84 sounds the buzzer and switches the channel to the video in channel so I can see who is there and then after the 18 seconds it activates the previous channel button on the remote control so I can continue watching my program.

    I have a TV in my bedroom, my electronics room and another TV in my shop hooked to this system. Its real handy to have the TV turn on automatically so you can see who is there, instead of having to get up and go into another room to look out of a window or having to go downstairs to look out the door. I was tickled pink when it was completed and actually worked. I've had the system up and running for almost a year now with no problems.

    In the designing phase I did have a problem when I tried to run the AC from secondary windings of the transformer to the 16f84 circuit board, it wasn't working very consistent as I was getting some sort of interference from placing the 100 volts ac on the board to operate the photo circuit. I never figured out why it wouldn't work right or what I was doing wrong but I decided to put the neon bulb and the photo circuit with the transformer and had it operate a relay that sent a dc signal to the 16f84 instead of the 100 vac and then it was 100 percent consistent and worked like a charm.

    The only part of the code that was hard for me at that time was to configure a partial closed loop for the 18 second timing, when the motion detector signal was first detected and to have the code start the 18 second timing period again if the motion detector signal was detected before the end of the 18 seconds. I did have help with that part of the code from others that I really appreciated it. The rest of the code was pretty straight forward and easy to write. It just goes to show you that with a little help that anything is possible (from a hobbyist standpoint or for anyone for that matter). With all the resources that are available on the net it seems that our only limit to accomplishments is our imagination.

    I hope someone will enjoy my rambling's here.....................jessey
     
  6. motion

    motion New Member

    Joined:
    Jul 14, 2003
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    Location:
    Quezon City.PH
    The most fascinating PIC project I had worked on was an automatic urinal flusher. These were battery operated ones that detected a person approaching the urinal and would automatically flush water twice, one before and once after use.

    Being battery powered, power consumption was important. So, I used the PIC16F84's watchdog timer feature to periodically wake the circuit after going to sleep for a fraction of a second. Once awaken, it would fire a short burst of 38Khz pulsed IR beam. If there was a person present, the IR beam would reflect from the body and be detected by an IR sensor. This sensor was sensitive to the 38Khz frequency and so was able to discriminate against any background source. If no person was detected, the circuit was put to momentary sleep to conserve power until the next watchdog reset.

    Using a 455Khz clock frequency on the PIC, the 38Khz pulse was generated by using just 3 instructions repeated several times.
     
  7. ivancho

    ivancho New Member

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    Location:
    Kansas
    I used a PIC to generate the comands needed to drive a X10 protocol to turn the lights on and off in my apartment. I hooked it up to my PC with a map of the apartment and in it all the sockets I was able to control.

    There 3 lamps I would have to turn on when it gets dark to have some light aournd my computer. Nothing better than turning all those lights from the computer........ of course my girlfriend asked me if she had to log on to the computer to be able to go to the bathroom :lol:

    Great fun
     

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