Freescale micros...

Discussion in 'Embedded Systems and Microcontrollers' started by JohnnyD, Jul 1, 2007.

  1. JohnnyD

    Thread Starter Well-Known Member

    Aug 29, 2006
    79
    0
    Hi,

    I've just spent the last few days reading through the instruction book that came with my Freescale HC05 development/simulator board. I got given it from a relative a while ago and its pretty old (the copyright on the book is 1995) and i've found out, after speaking to the Freescale support team, that the HC05 series is being phased out in favour of the newer HC08 and HC11 series'.

    My problem is this - At some point in the near future, the micro which I've been learning about is going to be obsolete. I could move on to the HC08 series which would mean I have to get a whole new programming board BUT the assembly language instructions are the same so I wouldn't have wasted my time with the HC05. Or I could forget Freescale altogether and move onto either PIC or AVR (AVR probably slightly preferred due to the cheaper development tools) BUT I'd have to learn a whole different set of instructions.

    From looking around on the net there doesn't seem to be anywhere near as much information about Freescale micros as there is for PIC and AVR. Is this because Freescale are aimed more at the industry rather than hobbyist?

    What do you suggest?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    If you are learning academically, any microprocessor is about as valuable as another for the principles of programming. If you are planning to make use of the device, the thing to do is to examine the dozens available to find the one or ones that seem to be most useful to your applications.

    If you've learned one assembler, you can pick up another in a short time.
     
  3. JohnnyD

    Thread Starter Well-Known Member

    Aug 29, 2006
    79
    0
    Both really, I'm very much a beginner but I do have a lot of high-level programming experience and I will want to make use of micros in lots of projects I have planned. One annoying thing about the Freescale range is that from what I can tell, each family in the HC05 and HC08 range has a different programming/in-circuit simulator board so I'd have to choose one and stick to it cos I can't afford to buy lots of different boards. I don't know if this is the same with AVR or PICs.

    For example, the board I got given is the M68HC705JICS which can only be used with the MC68HC705J1A micro which is very basic. It doesn't have any hardware SCI/SPI or EEPROM built-in, which I would like to have for some future projects. I found a PDF document detailing how to write a software SCI but the speed is limited to 19.2K baud, whereas I would need around 30K baud for a MIDI device I want to make.
     
  4. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    I'm happy with the Arduino http://www.arduino.cc

    I also picked up a micropower MPS340 kit from TI for 20 bux. ;) It's all in a USB stick! It is limited but it's really efficient on power. Ti is a little to windows centric with it's software, a drawback IMHO but still too cool to pass up. My only other gripe is the extra MPS boards are reduced feature ones, not the one that comes with the USB devkit.
    http://www.ti.com/corp/docs/landing/ez430tool/index.htm

    Freescale does not seem to be very friendly to hobby use at all. 249 is one of the prices I found for a devkit if you can call it that. I also don't see a very friendly website and lots and lots of proprietary this and that.
     
  5. Papabravo

    Expert

    Feb 24, 2006
    10,148
    1,791
    I would continue using the free stuff to learn from while at the same time beginning a search for an alternative. As you search for an alternative you will have some yardstick with which you can make an informed comparison.

    As others have said, learning a processor and a toolset is seldom a wasted effort. The knowledge is readily transferable. The first of many assembly languages that I learned was FAP(Fortran Assembly Program) for the IBM 7090. Havn't written any code for that machine more than 40 years, but I've never regretted makeing the effort to learn it.
     
  6. JohnnyD

    Thread Starter Well-Known Member

    Aug 29, 2006
    79
    0
    Thanks for the advice everyone :)

    I think I'll buy a few HC05 chips while they're still available and use them for a while to learn with, and to build simple projects that don't need things like SCI/SPI/EEPROM, etc...

    I think once I get enough money I'll buy the Atmel starter kit for the AVRtiny/mega series of chips for a few reasons. First, the chips are flash programmable so I won't have to spend £70-odd on a UV light box to erase EPROMS (the HC05 are all EPROM). Secondly, the AVR starter kit can program a large range of the AVR chips, not just one. The Freescale board I have at the moment can only program the HC705J1A and nothing else, and as far as I can tell, the new HC08 is similar, ie - you have to buy a seperate development board for each variant of the HC08. If there is one Freescale development board which can program/simulate all chips in the HC08 range I've yet to find out what it is, and it'll most likely cost well over £1000 which is waaay over my budget. which brings me to the Third reason - cost. The AVR starter kit is only £70.

    I've almost finished writing my first program for the HC05 and I see what you mean about it not being wasted time. I can see now how easy it would be to transfer to a different CPU, provided you have a good reference book. I thought at first it'd be really hard programming assembly language but I'm finding it almost as easy as BASIC, even debugging the machine code! I just need to learn how to compact my code a bit better using indexed addressing but that's another thread.

    Thanks again.
     
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