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Open Source Thermostat and more (Schematics)

Discussion in 'Electronic Basics' started by William at MyBlueRoom, Feb 21, 2006.

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  1. I've just put up a very basic (schematics only at this time) site.
    There are currently four projects:

    Cricket Communicating Thermostat (IR, iButton, RS232 or 485)

    Ladybug Super IO Controller (RS232 & RS485, RTCC with 24hr backup,
    relays, 3 digital & 1 digital/analog input, 1 iButton)

    Daisy Communicating Clock (six digit RS485)

    and just for fun Dice

    All are PIC Microcontroller based, some are configurable at build time.

    Example: Cricket will work stand alone (1 relay) or mate with Ladybug
    relays) similar hookup to an RCS type thermostat.
    Ladybug can be standalone similar to an Elk Magic 443, but with more
    both RS232 & RS485 and a RTCC as standard. Can be upgraded to 32K when
    a PIC 18F2525 instead of the standard 16F876

    Also all (except the dice) can be reflashed via the serial port
    and the Ladybug supports ICD/ICP

    I'm looking for ideas, advice etc... I want to make open source home
    automation products for anyone to afford & use. Also any help would be


  2. PeteG

    PeteG Guest

    I think you've got that the wrong way round. The Daisy and Cricket both
    show a 16F628 PIC which can't use a bootloader to self program the FLASH,
    they can do LVP/ICSP. It's the 16F876 that can do both.

    I'm also intrigued how the key switches work on the same two schematics
    since the key scan diodes will pull the input low when a key is pressed, but
    there is nothing pulling the RA5/MCLR pin high. Have I missed something?

  3. Thank you Pete, I'll correct the schematics in both and repost. My
    tech-tools emulator has a weak pullup on MCLR I forgot to include in
    the schematic.

    I'll also use the PIC 16F87 in Cricket, I've found several bootloaders
    for that one.

    I wanted to get feedback like yours before commiting to PCBs. I'm also
    trying to find a better way than using a opto isolator for power loss.

    PS the display in the Cricket uses a method called Charlieplexing

  4. I've added two more schematics to the page, I've put Fiddler Crab on
    hold while I write up descriptions on the six projects on the site.

    The added schematics include:

    Owl a iButton / 1wire security system (simple to show what can be done
    with a 8 pin PIC)

    Beetle (low cost) addressable remote temperature sensor (another 8 pin

  5. Ken Moffett

    Ken Moffett Guest

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