Finding the right microcontroller

Discussion in 'The Projects Forum' started by BlackOps, May 27, 2016.

  1. BlackOps

    Thread Starter Member

    May 23, 2016
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    (EDIT)
    Question:
    I found a PIC12F519 ic laying around here. Its from a 2 button remote which i found back in 2014. It was used for a gate and didn't work. However i managed to get it to work now and this PIC chip works perfect.


    I want to know 1 thing before ripping this thing of the board, can i change the output polarity? I need negative V- output with the 20Hz pulse. So the programming should be easy but i need to know if i can change the output polarity by programming it. I can't find anything on the datasheet and so for the internet.

    So i need v- as output, not v+.





    Hello, i'm searching for a micro-controller, a very small one. Something like a SOT23-6 package or QFN, which i DO NOT have to program. What i need, is a microcontroller, that pulses ground with a duty cycle of 20% at 1Hz. I know its possible with an 555 timer, but it won't fit in an small flashlight housing so its kinda useless. I need something like SOT23-6 or QFN without external components if possible, (Running on "2V~4.20V")

    Pulse has to be GND
    (NO output resistance if possible)

    And is there a Hall effect sensor that is (momentary)? So whenever i put a magnet against it, it will make GND continuous, but whenever i remove the magnet (regardless of what pole), it would cut the continuity of GND off.

    Do i need a microcontroller for that? I really wan't it to work. And ground is what needs to be switched, not the V+ line.

    All help is highly appreciated:D
     
    Last edited: May 30, 2016
  2. Papabravo

    Expert

    Feb 24, 2006
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    Explain to me how you intend to pulse the low impedance GND line connected to the power source. There are no microprocessors that someone doesn't have to program. I've never seen one in a SOT23 package but that doesn't mean it doesn't exist. Rotsa Ruck
     
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  3. nsaspook

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    Aug 27, 2009
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    A PIC10F204 would work for size and voltage range but it only sinks 25mA so you would need a external driver for more current and someone will have to program it but that's a trivial job if someone already has a setup for this chip. The controller could easily handle the Hall sensor requirement (with appropriate outputs) with a Comparator.
     
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  4. BlackOps

    Thread Starter Member

    May 23, 2016
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    Wow, so i also found a similar ic, the PIC10F200T, but for the output signal, the output is probably V+, can i switch this over to GND with a comparator? Never tought obout it. Thanks anyways!
     
  5. nsaspook

    AAC Fanatic!

    Aug 27, 2009
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    Look at the datasheet.
    The PIC10F200T is missing the Comparator module for detecting a possible analog Hall sensor level. You're not clear about the output requirements. Can you post a simple schematic (wiring diagram) of what you need to do.
     
  6. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    As I suggested in your other thread any of the 10F2xx, 10F3xx, or even 12F processors will do what you want, assuming it has the peripherals you need. The 10F's are smaller. As for programming, what you want to do is not much different than flashing an LED, which is often the very first tutorial.

    I started with Assembly and have stayed with Assembly language. For what you want to do, that is what I would suggest as well. Someone might be willing to do it for you gratis or a small fee.

    John
     
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  7. BlackOps

    Thread Starter Member

    May 23, 2016
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    I made the schematic, the output pin must be momentary, so when the magnet is removed from the Hall sensor, it should stop the continuity, when magnet is applied, it outputs ground. Regardless of the magnet pole.

    So by applying an magnet, the IC outputs ground to the SOT23-6 IC in the diagram, this is to turn the unit on, this is an battery management system, and the only way to turn it on, is to apply Ground to the pin where the wire is attached to in the diagram.

    The package needs to be as small as possible like SOT or QFN.
     
  8. BlackOps

    Thread Starter Member

    May 23, 2016
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    Thanks for your reply, i'm still looking for it, i contacted some sellers on Aliexpress who sell them, to ask whether the can program it for me. The down side is, that it has good resistance, which is not very nice, but i can use this for strobe mode, and whenever i apply the magnet to the hall sensor, it goes over to constant wave.. When i turn the device off, and on again, it automatically goes to strobe, thats a cool feature. But i'm mainly searching for the ic in the diagram posted in my previous post. But if someone on Alixpress can program this micro processor for me, i will order it and use it as a strobe mode.
     
  9. jpanhalt

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    Jan 18, 2008
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    Custom programming is probably quite expensive for a few chips. Even more expensive would be writing the program, which I doubt Aliexpress does. All you need to program is a computer and a PicKit3 (made by Microchip). Since Microchip has a vested interest in getting people to use its chips, I don't believe anyone pays retail for that programmer, if they bother to ask. I woud recommend getting the authentic PK3, not a counterfeit.

    No microcontroller will deliver lots of current. However, they can switch relays, and even better, they can switch logic level mosfets directly. Again, programming the chip is not a hurdle. It is writing the program and maintaining it that requires some work (unless you think your very first program won't need any changes). ;)

    John
     
  10. Papabravo

    Expert

    Feb 24, 2006
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    WARNING: You might consider the following comments harsh. My interest is in helping you to better specify the project since you need help from other people -- specifically someone to program the chip.
    Your schematic is not really a schematic; it is more of a block diagram. A proper schematic would have part numbers, with the pins labeled, using proper symbols. Your drawing is impossible to follow. I can't believe that you will have a reasonable chance of success with this project, especially explaining to the programmer of the chip what you want to do and then getting the result you expect. If I was still in the consulting business I wouldn't touch this project with someone else's 10-foot pole until there was a proper schematic. There are may examples of proper schematics to learn from and I would start there, once you select a candidate microprocessor chip.
     
  11. BlackOps

    Thread Starter Member

    May 23, 2016
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    Yea sorry for the diagram, well i got over it. I had one more wuestion, i need to find a IC which creates a clock signal trouvht the laser diode, just a frequency wave, are there any IC's? I found a IC, the ST 25P10AV which has a clock signal pin, can i use that? Thanks!
     
  12. jpanhalt

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    Jan 18, 2008
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    Your original query included the 555. That is an early IC and provides a clock signal. Also, many people here have given you suggestions for other IC's that provide a clock signal.

    At this point, it seems that what you mean by "clock signal" is not what is that term is commonly understood to mean. So, what do you mean by "clock signal."

    John
     
  13. dannyf

    Well-Known Member

    Sep 13, 2015
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    Learning to code a mcu to do that is fairly easy.

    Even if you cannot, you may be able to get someone else doing it for you for a fee or even for free if you catch them on a good day. Getting the code and burning it to a mcu is small potato.
     
  14. BlackOps

    Thread Starter Member

    May 23, 2016
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    Hello Jhon, the 555 timer unfortunately wont fit in my project due to the components to set it up, the package alone will fit but it wont work. My project is actually complete, but i have a little bit more space so i came up with an idea, and i inow for a fact, this would be cool to do next year at school as we are going to design circuit boards and i want something like optical audio. I will attach a picture,

    I want some type of frequency like that in the laser beam, this would be fun to measure with an oscilloscope next year.

    A clock signal between 800hz and 1500hz. So its in the laser beam. Just a IC that creates a clock signal like that, just like optical audio but the frequency is constant.

    Are there any IC's for this, as small as a SOP-8 package or smaller without external components and programming? The output polarity doesn't matter but the input voltage must be in between 2v to 5v or higher. Thanks!
     
  15. BlackOps

    Thread Starter Member

    May 23, 2016
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    Yea true, i already got someone on aliexpress who could do that for me :D The problem is, that i do not have equipment to do it. I love to learn stuff and program, but i unfortunately don't have the equipment to program it
     
  16. jpanhalt

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    Jan 18, 2008
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    Yes, there are. Several of us have been mentioned options, including Schmitt triggers and SOT23-6 microcontrollers. There are even smaller devices. Clearly, we don't understand what you mean, or you don't understand the answers. Specifically, how does a relaxation oscillator based on a single or dual Schmitt inverter fail your specification? How does the internal oscillator of a PIC 10Fxxx chip fail?

    Your diagram doesn't make sense. Do you understand that lasers operate in the terahertz range? Are you intending to somehow modulate the laser at a much lower frequency?

    John
     
  17. BlackOps

    Thread Starter Member

    May 23, 2016
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    Hello Jhon, yea, its hard to explain as i don't know how to explain it unfortunately, but i will go for the strobelight. So basically, what i want is 20Hz of negative output. This way, i can make a strobe laser. Can this be done with the PIC12F509 micro-processor chip? I can get those very cheeaaappp so i really like this IC. Especially if it can do this with negative output. I can make a good schematic this time if you need one.

    So basically, 20Hz negative V- output.

    By the way, are those micro chips idiot proof? Lol
     
  18. nsaspook

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    Aug 27, 2009
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    Nothing is.
    [​IMG]
     
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  19. dannyf

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    Sep 13, 2015
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    fairly easy to do. I took the code I showed on the 16f54 clock project and made a pulse generator: 2 pps, 10% duty cycle (active low). on a pic10f200, it takes 134 bytes of flash and 15 bytes of ram, without any optimization. So still more room for other features.

    I think you will find for long-period precision timing, simple mcus is really the way to go.
     
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  20. BlackOps

    Thread Starter Member

    May 23, 2016
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    Hello Danny, i'm thinking about buying a programmer. I got a couple questions to you, is it possible to have negative (V-) pulsing at 20hz? And i'm new to programming, can you point out what i exactly need to program a MSOP-8 MCU? I want to program, the PIC12F509. I just can't figure out what i need. Thanks!
     
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