help location duable micro processors

Discussion in 'The Projects Forum' started by ThomasHA, Nov 17, 2012.

  1. ThomasHA

    Thread Starter New Member

    Nov 17, 2012
    3
    0
    Hi,

    New to this fantastic forum, so hope you guys and girls can help me.

    I'm in the middle of a project. The project is about search and rescue Where I'm making a lifejacket that has an incoorporated GPS sending unit in it. It will activate when wet and will be powered by a battery pack.

    It has to be able to withstand saltwater, some "beating" when handeling and as small as possible.

    I'm working in a group of 4 people, and my area is this micro processor.

    I was thinking a micro processor that need to have 2 pins activated before working. The reason why I think 2 pins is better then one, is because I don't want the processor to start up the gps sending a distress signal if it is not needed. I have one sensor that will open when it is activated (wet => person overboard), but I might use 2 for the same reason why I want the micro prosessor to have 2 inputs before it activates.

    I will then need som output to the GPS as well comming from the micro posessor.

    Is there a Micro processor you can recommend that would fit in my application?

    Best Regards,
    Thomsa
     
  2. nerdegutta

    Moderator

    Dec 15, 2009
    2,519
    786
    Hi.

    I cannot help you with this project, but others might. I have however made a simple block diagram of what I think you are wanting to do.

    What do you have do far? GPS receiver? How will the gps data be sent? Do you have the sensors? How is this going to be powered?

    [​IMG]
     
  3. spinnaker

    AAC Fanatic!

    Oct 29, 2009
    4,887
    1,019
    I hope this project is for educational purposes only and not for actual use, because if you are asking these types of questions here then you are simply not qualified to be designing such an important lifesaving device. Leave that up to the experts.

    If this is for educational purposes then you can start with a parametric seearch for your mcu. Most of the chip manufactures have them.

    Here is one for the 18F family from Microchip.

    http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=1004&mid=10&lang=en&pageId=74

    But before you even get started, you will need to decide first on a manufacturer of chips. Then a family.

    Microchip is very popular on this forum. It is cheap to buy, cheap to program and easy to program.

    I like the 18F family from microchip simply that is what I started with and supposedly they are optimized to work with C.

    There are GPS chips available too that interface to mcus.
     
  4. ThomasHA

    Thread Starter New Member

    Nov 17, 2012
    3
    0
    sounds good, and yes this is for educational purpose only!
     
  5. ThomasHA

    Thread Starter New Member

    Nov 17, 2012
    3
    0
    those GPS chips, do they have connections to connect a GPS directly?
     
  6. spinnaker

    AAC Fanatic!

    Oct 29, 2009
    4,887
    1,019
  7. ErnieM

    AAC Fanatic!

    Apr 24, 2011
    7,395
    1,607
    GPS chips typically use a low speed serial stream (think RS-232 but without the level shifting) to get the data. Just about any processor will handle that.
     
  8. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,871
    1,394
    I suppose you have researched EPIRB, but If not, you should.
     
  9. spinnaker

    AAC Fanatic!

    Oct 29, 2009
    4,887
    1,019
    Yeah I was out on an afternoon bicycle ride thinking about this project. I just couldn't fathom (pun intended) why the OP would want to interface a mcu to a gps. But after looking more closely at the block diagram provided by nerdgutta I see that the OP does intend to build a gps.

    OP,

    Why? What you are talking about is building an EPIRB. It has already been done and very well by a number of manufacturers.


    A GPS does not transmit your position. It simply records it. To report it, you will need a transmitter. An EPIRB is a combination of GPS and transmitter that transmits the GPS postion to a satellite. The EPIRB is designed to work under extremely harsh marine environmental conditions.

    I would think building such a device would be very expensive. First there is the materials but then you would most certainly need a license to transmit on those frequencies and no telling what hoops you need to jump through with your Coast Guard or what ever it is called in your country. You just can't set one of these off or you will face very stiff fines.

    Now if you wanted to build sort of a pseudo EPIRB. Perhaps transmit on blue tooth,IR or even broadband then that would be very affordable and doable legally. Of course then you would need to build the receiving station.

    Sparkfun has various modules like the GPS module that could be used for transmitting and receiving digital information.

    I am pretty surn they have a module that transmits on broadband that acts like a web server. The GPS could pick up the position and the mcu could provide that to the webserver.
     
Loading...