What microcontroller should I buy?

With so many different types of microcontrollers and manufacturers on the market, it is rather difficult to know where to begin.

What I need is something that has the following features:

  • very small in size
  • very low power consumption
  • at least 64 k of storage purely for storing data (this is in addition to my program's space)
  • some sort of interface to connect the microcontroller to a PC (RS232, USB, etc) to allow the microcontroller app to transfer logged data.
  • an interface to communicate with a serial peripheral (RS232 would probably do)
  • low cost or free Integrated Development Environment (IDE) with debugging capabilities
  • low cost or free C or Basic compiler (or some other high level language)
  • low cost hardware kit for flashing the microcontroller and debugging

The applications running on the microcontroller will generally be small. Also, if it isn't possible to have at least 64 k of built-in memory, I can live with adding the memory externally but the enhancement should be easy to do.

Can anyone please make any suggestions on any products / manufacturers that have what I am looking for.

Thank you Johann Blake

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A good place to start is

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where you can select PICs based on your options. Combining your requirement for low pin count and 64K memory gives 3 28 pin PICs with

64K (18F26xx). Microchip also offer the MPLAB IDE as a free download.

You could either prototype your design on a standard breadboard and use discrete components to build the interface to the PC to communicate with your application on the PC, or use a development system like these

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MikroBASIC also offer their own high level language and compiler. The freeware version is limited to 2K which is ample for most applications. More details

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For programming the HEX to the PIC you could either build you own programmer or purchase one from as little as $12 from Spark Fun

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although some of the development systems above also include the programmer, so its really down to your budget and personal preference.

Other languages you might want to look at are; JAL & JalEDIT - (JalEDIT is a freeware IDE for use with JAL) PicBASIC (pro) CH BASIC MBASIC

Just goggle or Yahoo for the above.

That should be enough for you to be getting on with :-)


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You will probably need to add an external 64k EEPROM or similar to get what you want easilly AND cheaply (in fact if you plan to log lots then perhaps a RAMTRON device would be better). If that's the case then any micro will probably do(depends of course what you want to do with it). I guess you'll be driven by the cost of the tools. So... There's always free C compilers somewhere (see a short list below), usually with some limitations [code size etc.] and therefore the debugger might be your stumbling block... but then again processors with on-chip debug facilities are usually good for low cost debuggers.

There are several very low cost debuggers for Microchip PICs (quick search on web will list lots) Many are less than $99. Reasonably low cost for HCS08 etc. As far as 'flashing' the micro... your debugger can probably do that for you.

Compilers Microchip PIC18 = free C18 compiler download from Microchip (not code size limited but code optimisation limited) along with MPLAB IDE ST ST7 = free 16K version of the Cosmic compiler and use STs visualIDE & debug system Motorolla HCS08 = Metrowerks 4k limited compiler (Version 5 available Jan

2006 will be 8k or 16k I believe) Renesas have a 64k limited (if you call that limited) C compiler... and so on...

The web is great for finding these tools.

This info probably hasn't helped you choose your micro family. It's all very subjective and I wouldn't want to influence you by just mentioning my favourite. Good luck Jim

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Serial EEPROMs are (relatively) cheap and simple to interface. They also have the benefit of being non-volatile but at the price of being a bit slower than a "main memory" SRAM space. Search Digikey for "serial eeprom" and take your pick. (no pun intended ...)

You could also go with an MMC card for removable storage.

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has pointers to a low cost commercial FAT file system for MMC cards or, if you just need flat storage space, the MMC interface spec is available on the net.

Lots and lots of microcontrollers come with integrated UARTs. Generally you'll need to add the level shifter, commonly a MAX232A or equivalent.

The WinAVR project is linked off the AVRFreaks site above. Personally I use the Imagecraft AVR C compiler; not free but reasonably priced and a good product.

Atmel's "AVR Studio" works with the Imagecraft compiler as a source- level debugging environment. You can get the AVRISP in-system programmer for about $30.

Rich Webb   Norfolk, VA
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Rich Webb


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or type in technological arts on google. I would recommend 9s12 microcontroller. It is compact, cheap and efficient. They have Adapt9s12 where you can connect to your PC to program and debug. If you order one from them you can also get the compiler for free. Plus they can help you if you have questions, they also have toll free number on their website.

Later, Wojtek

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Any micro controller that supports external memory will serve your needs provided you interface the required external memory. I prefer the megaAVR family over the PIC's because they are well supported by the "C" language using the 'free' GNU compilier. The fact that there is a low cost JTAG ICE available for debugging is icing on the cake.

If you outgrow the AVR family there are several variants of the ARM processor family that can directly address as much as 1 megabyte (or more?) of memory.

BTW the AVR is a Harvard class machine, the ARM's are Von-Neuman (if that matters).

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Ken Scharf

How does the JTAG ICE work in a Linux environment? I recently started playing with the stk500 and atmega8515 in linux. I have avrdude and avr-gcc working flawlessly but am wondering about any issues that might surround using the JTAG via USB in linux.

BTW: seems that the AVR family has a better mips:hz ratio than PIC too.

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