Using Microcontrollers from Old Electronics...

Discussion in 'Embedded Systems and Microcontrollers' started by cpman, Feb 5, 2014.

  1. cpman

    Thread Starter New Member

    Feb 5, 2014
    I am new to these forums.
    I have experience with microcontrollers and circuitry.

    I have a question that I could not find answers to on Google.
    Firstly, some background:
    I like taking things apart. In the past, I took apart an old phone, and was looking into using the CPU for some sort of project. I spent 5 hours searching for a datasheet, and did find one. Unfortunately, I would have needed to reball the chip to use it, and I'm not capable of that.
    Ever since then, I have wanted to use a microcontroller from old electronics, like flash drives or phones.
    Yesterday, I took apart a hard drive. It is fairly clear that there are 2 CPU's on the board. Every time I search for one of the numbers on the chips, all that comes up is people selling replacement boards. These CPU's are just standard surface mount chips, so I will be able to use them if I desolder them.

    Do you have any suggestions about where to find a datasheet for these chips, so I can figure out how to use them?

    Here is the motor controller chip:
    Here is the main CPU:

    Thanks for paying attention to this post!
    Last edited: Feb 5, 2014
  2. takao21203

    Distinguished Member

    Apr 28, 2012
    1. Desoldered chips may work, but what I figured out, there is a chance some I/O ports may latch up partially. you don't get the full voltage swing anymore.

    Such errors are quite creepy when you don't have a clue about them.

    2. Really desoldering a 200 pin IC? How do you intend to reuse it? Make a PCB?

    3. Even if you get a datasheet and even if you become able to reflash the chip, you will need to use softwares almost nobody knows.

    USB Flash drives use 8051 derivates regularily- but most of them are epoxy encased.

    It is not really worth it. Even if there is a nice shiny PIC24- think the labour effort to remove + clean the chip.

    It will be more expensive than to buy a new chip.

    Besides the problem you will have almost no peers online to ask questions about that controller chip.
    cpman likes this.
  3. spinnaker

    AAC Fanatic!

    Oct 29, 2009
    Most of those chips are proprietary. That is why you can't find the datasheet. Even if you could desolder them and find the dataheet somewhere I doubt you could be able to program them.

    Wy go through all of that hassle for a chip that may or may not work? Many Pics sell for under $4 US and you will find tons of support for them.
    cpman likes this.
  4. cpman

    Thread Starter New Member

    Feb 5, 2014
    I mostly want to do it for fun, but I probably am better off sticking to well-supported chips like ATMEGA and PIC chips, where I am able to access the datasheet...
  5. MrChips


    Oct 2, 2009
    As others have indicated, don't even bother to unsolder those CPU chips unless you are absolutely certain it is an off-the-shelf reprogrammable part.

    Most of those MCU chips are proprietary and you will not be able to reprogram them.
    Also, off-the-shelf new MCU chips are so inexpensive you would be further ahead to start with a brand new chip.
  6. Brownout

    Well-Known Member

    Jan 10, 2012
    At a buck or two a throw for a brand new UP with free compilers, IDE and all docs, it wouldn't make much sense to try to salvage an old processor. Even if you found all the docs, you might not be able to get a compiler or assembler. Spend a buck and getg something useful. You can get a PIC is a DIP so you can use it with a breadboard.