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help: Choosing a MicroController (HAM radio) and some other points

Discussion in 'Electronic Basics' started by renjith, Mar 10, 2005.

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  1. renjith

    renjith Guest

    I am looking for a micro-controller to use for my varsity project (ham
    radio). I am not a great expert in micro-controllers and am not quite
    sure what uC's I should considering. My priorities with choosing the
    uC are as follows:

    - General: Reliable and some sort of support available for the uC
    would be great. Relatively affordable.

    - Hardware:
    Code Memory - 16-32K
    Internal RAM - >256 bytes
    UART - At least one
    Preferably SPI (in-system programmable)
    Preferably DIP version available
    Preferably low voltage (5-10V ?)
    Preferably >15 I/O pins

    The code memory is because I intend to use C and am not yet sure
    about the potential length of my program could come to,
    whereas the RAM is to store packets that may be larger than 256
    bytes that can be dealt with in memory as fast as possible. At
    least one UART should be present, though more than one would be
    great. An onboard FSK 1200 baud modem chip would be super but
    not absolutely needed. A reasonable amount of I/O lines would
    be great.

    - Programming :in C (for free): This is a must. Maybe I'll
    consider other medium-level languages like Visual Basic/etc,
    but not assembly. I am familiar with assembly before and I'd
    definitely prefer C in any case, probably using assembly only
    in certain routines. I'm also looking for a free C compiler
    since varsity won't be assisting financially and I'm not exactly
    loaded with cash. The PIC would have been a great choice in this
    aspect but I won't be using the PIC and 8051 for my project
    (regulations).

    - Other: A programmer. I'm not highly familiar with uC's, and
    for the 8051 and PIC there are lots of programmers available.
    What happens when the uC is new/with not a lot of support? Does
    the user have to try and design one him/herself? I would like
    to choose a uC that has a programmer (schematic) already
    available.

    I really need to make sure that I chose a reliable microcontroller that
    I would be happy with. I would like to look at all possible
    uC's available with regard to the above criteria.

    Help would be highly appreciated.
    Renjith
     
  2. Well,

    Have a look at the Atmel site.
    http://www.atmel.com/dyn/products/datasheets.asp?family_id=607
    The ATmega8 for instance seems to fullfill all your needs. Programming
    circuits can be found easily and you can also find a GNU C-compiler for
    free.

    You can also find similar PIC and 8051 controllers so what strange
    regulations make you have to look for others?

    petrus bitbyter
     
  3. Rich Grise

    Rich Grise Guest

    Because the teacher said so.

    Cheers!
    Rich
     
  4. Guest

    Many microcontrollers suit your needs. But I would recommend the
    ATmega32. Plenty of flash and RAM for you, DIP package, ISP etc. The
    board is supported by numerous free programmers, or you can buy the
    official development board (STK500) which is <US$80. C compiler
    (avrgcc) is free. I've done several contract projects using exactly
    this combination and I'm very happy with it.

    BTW, 5V is considered a high-voltage part these days.
     
  5. mc

    mc Guest

    When did ham radio get to be HAM radio? "Ham" is not an abbreviation.

    VY 73
    N4TMI

    P.S. I know the story about H.A.M. standing for the names of 3 ships, and I
    know that it's pure fiction.
     
  6. Tauno Voipio

    Tauno Voipio Guest

    How about the story of messrs. Hyman, Almy and Murray?

    73!
     
  7. renjith

    renjith Guest

    Thanks a lot petrus and l..., I took a look at the
    ATMega series and many of the uC's there seem highly
    suitable for my needs. However could you also mention
    a list of other possible uC's just for information sake
    if you dont mind ? Someone suggested the Motorola 68xxx series
    to me which I've also looked at and seem promising but I haven't heard
    anyone else mention about it. Thanks a lot for your suggestions and
    I'd really appreciate any other feedback.
     
  8. Hi,
    Try to "search" the Internet for projects similar to your project.
    There are many HAM radio projects utilizing different microcontrollers.
    Some use PIC microcontrollers, some AVR, some '51, some ...
    A small collection of pages that I have in my "bookmarks" :
    http://homepages.compuserve.de/WoBuescher/DL4YHF/pic_key.html
    http://www.qsl.net/zl1bpu/micro/
    http://www.myplace.nu/avr/minidds/index.htm
    http://www.qsl.net/zl1bpu/micro/SIGGEN/Siggen.htm
    http://www.commlinx.com.au/microcontroller.htm
    http://www.qsl.net/ok2tej/elbug/elbuge.html

    Best regards,
    Jacek.
     
  9. Here is that story:

    http://www.w8eup.org/orgin_of_word_ham.cfm

    Interesting, I had no idea where it came from before.
     
  10. mc

    mc Guest

    Anybody can make up a story. That doesn't make it true. Besides, if it
    were true, the names would be definite, and verifiable... as it is, they
    vary from version to version.

    "Ham radio" is from "ham actor" and refers to the amateur entertainment that
    was often broadcast by early radio experimenters. Hams weren't prohibited
    from broadcasting until after WWI.
     
  11. mc

    mc Guest

    And you still don't, because as far as I can determine, that story is pure
    fantasy. Why would a "Mexican ship" have a name that is almost
    unpronounceable in Spanish?

    Given the Harvard connection, it sounds as if it might have been made up as
    a tall tale by students. But I don't know that. At minimum, does the
    Harvard Wireless Club have any records that support it?
     
  12. mc

    mc Guest

    I should add one more thing.

    There may well have been one or more early stations whose operators'
    initials were H, A, and M. That doesn't make that the origin of the term
    "ham radio." The usually accepted origin is that it comes from "ham actor."

    Arguing strongly against the Hyman et al. theory is that nobody wrote "ham"
    as an abbreviation ("HAM", "H.A.M."), as far as I can tell, until the 1990s.
    It is always "ham radio," not "HAM radio" or "H.A.M. radio," in publications
    from more than 10 or 15 years ago.
     
  13. Ian Bell

    Ian Bell Guest

    I would recommend the 8051 and its variants. Philips make a good range with
    various sizes of code and data spaces and all have ISP. There are many free
    simulators available and many of the major IDE vendors have evaluation
    versions with a 2K or 4K code limit to get you going in C. For bigger
    programs you can use the free C compiler SDCC.

    Ian
     
  14. Of the 80C51 variants, the easiest to get going, because it includes
    On-Chip debug, is the SiLabs C8051F family. These also have low cost
    eval PCBs, so if you want to skip PCB layout, sub $30 gets you
    the 064 Eval kit, with dual USB links, one for data, one for debug.
    For small volume usage, they have one device in DIP20, but they
    do not target that sector.
    Others with on-chip debuggers are Winbond, and ST's new uPSD3400
    series have a lot of resource.
    -jg
     
  15. If you are wanting to compare microcontrollers, you could always look at
    the Motorola HC08 series. A table of features is at:

    http://www.freescale.com/webapp/sps/site/taxonomy.jsp?nodeId=016246844976638634

    Simon.
     
  16. One often overlooked microcontroller is the Zilog Encore Z8. It is a
    3.3V process, comes in DIP, supports C (they have a compiler for it,
    it's not GCC) and supports source level debugging through a debug pin.
    Look at the website. They usually have eval kits (I got one a few years
    ago for less than $100) which comes with a processor, some peripherals,
    a couple of RS232 ports (one for debugging, one for talking to the thing
    through the UART).

    I found it quite nice, until I discovered PICs. The main advantage I
    find with PICs are that they come in 8 pin, internal clock packages.
    Thus, they are that they are incredibly simple to prototype with.

    --
    Regards,
    Robert Monsen

    "Your Highness, I have no need of this hypothesis."
    - Pierre Laplace (1749-1827), to Napoleon,
    on why his works on celestial mechanics make no mention of God.
     
  17. You will find plenty of more information on the AVR on the www.avrfreaks.net
    website.
    Tools:

    * AVR Studio - Assembler/Debugger/Simulator/ICE Frontend.
    * STK500 - Development Kit/includes an In System Programmer
    * JTAGICE Mk II - Low cost emulator, allows you to download code, run, set
    breaks and singlstep.
    * WinAVR - gcc compiler for the AVR

    Some commercial compilers
    * IAR
    * Imagecraft (Hi Richard!)
    * Codevision


    --
    Best Regards,
    Ulf Samuelsson

    This message is intended to be my own personal view and it
    may or may not be shared by my employer Atmel Nordic AB
     
  18. So do the Z8 Flash parts ? ( but only recently )
    -jg
     
  19. Right, it's an acronym. AIUI, Home Amateur Mechanic was a real magazine
    that ran real articles about building your own amateur radios.
     
  20. Apparently that's an urban legend.

    http://www.ac6v.com/hamlid.htm

    "Unfortunately for this story, none of it checks out. A past president
    of the ARRL did extensive research in an attempt to confirm this
    story. There is nothing in the Congressional record about little station
    HAM. There is nothing in contemporary press records. And there
    is no record of a Hyman, Almay, or Murray at Harvard at the time
    this supposedly happened. This story first surfaced in an amateur
    publication in 1948, and doesn't seem likely to die. But it appears
    to have no factual basis."
     
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