Looking for an inexpensive microcontroller board.

Discussion in 'Embedded Systems and Microcontrollers' started by AverageGuy, Dec 27, 2009.

  1. AverageGuy

    Thread Starter New Member

    Dec 27, 2009
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    I have need for a medium sized board for a data control/logging application. I started looking at the Arduino project and while it is very attractive for a number of reasons, the data memory available is a serious limitation. Part of the requirement is to have a reasonable set of web pages and to support multiple modules connected to a I2C bus and eventually a one wire bus. The ethernet and wire libraries added to those requirements make data storage tight. Even the 16K of the Mega may give me problems and there isn't a realistic ethernet solution for it.

    I looked at the Beagleboard as a very attractive alternative, except for the lack of an ethernet port. I know a port can be added via the USB but that appears to add another $20 to the project. So I have a solution (Arduino Duemilanove and ethernet shield) that is ideal except for data storage and a Beagleboard which is an enormous overkill for data storage with a somewhat higher price.

    I have to think there is some product I'm not finding out there that will give me a reasonable amount of RAM, an ethernet port and a bit of digitial I/O (I2C) for something less that $170 but I haven't found it. I'm hoping there is something that has less than way too much (Beagleboard) and far too lotle (Arduino) for something inbetween price wise.

    Here's a list of requirements
    Ethernet port and software to drive it.
    64k of ram
    digital I/O (prefer an I2C port with software, but a couple of bi directional I/O lines will work)
    Price below the $170
    Programmable in C or C++ via a Linux cross compiling environment.
    Reliable supply source.

    I don't care if the development platform costs more since I'll only need one or two of them, however the finished product needs to be inexpensive.

    Anyone have suggestions as to what way I might proceed? I'd roll my own but the development money isn't there for such an ambious project. The resulting product has a limited market so there won't be a tremendous volume to spread the development money across.

    Thanks,
    Jim.
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
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  3. Markd77

    Senior Member

    Sep 7, 2009
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    I haven't done it myself but I hear it is pretty easy to hook up an SD card to a microprocessor. Search for Arduino SD card and you will find plenty of examples.
     
  4. AverageGuy

    Thread Starter New Member

    Dec 27, 2009
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    0
    Thanks, the function of system is to control "things" via relays, both mechanical, for DC circuits and solid state for AC circuits. Detect simple switch settings, ON and OFF, complex switch settings, like a switch with a resistor across it so you can detect ON, OFF and disconnected. Sense environmental conditions like temperature, humidity, light energy, etc.

    Have the ability to provide essentially a simple httpd function using passed parameters to control an output or set of outputs, and return settings found on specific devices. For instance a call of http://localhost:8888/set.html?module=2&io=OUTPUT&pin=3&cmd=ON
    Might close a relay on the module with the I2C address of 2 that is connected to pin 3 of some I2C part like bv4206 http://www.byvac.co.uk/bv/bv4206.htm.

    Jim.
     
  5. AverageGuy

    Thread Starter New Member

    Dec 27, 2009
    9
    0
    That's always a possibility. I've also never tried to connect one up but I have seen an ad for the SD interface to the Arduino. I'm pretty sure I'd have to have the MEGA board and the availability of an ethernet card for that board is limited. The standard Arduino ethernet shield (module) doesn't work with the MEGA board without bending/cutting pins and rewireing. There is a MEGA ethernet board available from a single source as a partial kit. They don't furnish the IC so you have to get it separate. However, I think the board design is open source and avaiable, I could pay a fab shop to make some up.

    Thanks,
    Jim.
     
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