Help choosing the correct low power microcontroller

Discussion in 'Embedded Systems and Microcontrollers' started by blaat82, Jul 19, 2011.

  1. blaat82

    Thread Starter New Member

    Jun 17, 2011
    Hi all,

    I would like some help for my summer project.
    I have a device that needs a microcontroller.
    In short, it should do the following:

    Read 3 analog inputs (each can give 3 different voltages)
    These inputs should be saved when the device is powered on.
    Whenever one of those inputs changes (voltage differs) after poweron, there should be send a signal through RF to operate a switch (power a (7)556 led/buzzer circuit for example)

    Everything has to run on a battery, so a very low power microcontroller is needed here.
    It also should go into sleep mode very often.
    So in other words, it has to check every 50-100 milliseconds if one of the inputs differs from those recorded when the device was powered on.
    The rest of the time, it should be in sleep mode to save battery.

    Now, I don't have any real experience with microcontrollers yet, but read google for a week or so to learn more.
    I've read about the very low powered MSP430 series from TI, but also a few PIC's that should work (have a pic16f1826 here)

    So basicly, I want to know which microcontroller is best suited for this.
    Keep in mind, I don't have a large budget for it (read: still need a programmer)
    As far as I could find, a MSP430 programmer is still expensive, where a pic programmer is cheap (especially clones)

    Can anyone put me in the right direction?
  2. ErnieM

    AAC Fanatic!

    Apr 24, 2011
  3. Markd77

    Senior Member

    Sep 7, 2009
  4. hgmjr

    Retired Moderator

    Jan 28, 2005
    ATMEL makes a line of AVRs referred to as pico-powered. These are ultra low pwoered devices like those already mentioned.

  5. MMcLaren

    Distinguished Member

    Feb 14, 2010
    The TI MSP430 LaunchPad with built-in programmer/debugger is only $4.30(USD). That's not too expensive, is it?

    Last edited: Jul 20, 2011
  6. blaat82

    Thread Starter New Member

    Jun 17, 2011
    Thanks for the replies.
    I don't get it why I didn't see the launchpad before?
    For that price, it's an auto-order :)

    Note, if I want to send a simple signal through a RF module, I need a msp430 version which supports USCI (UART) right?
    The ones delivered in the Launchpad package don't have this feature unfortunately.
    So I guess I have to try to get a few samples.

    Microchip also has a few good options, so i'll try to get a cheap PICkit 2 Programmer and start with those too.

    I'm not really familiar with ATMEL and programmers, but a few tutorials I'm reading use the ATmega168.
  7. MMcLaren

    Distinguished Member

    Feb 14, 2010
    Not necessarily. You could always bit-bang serial.
    The LaunchPad supports 14 pin and 20 pin "value line" devices so you might want to sample the new 20 pin MSP430G2553 which has USCI module (hardware serial port) as well as 16-kB Flash and 512 bytes RAM.

    Microchip is another good option. Programmer cost slightly more than $4.30 (lol).

    Atmel also a good option.

    Good luck. Regards, Mike