5x7 LED Matrix, driven by ATtiny4313.

By TigerUp
 
(tigeruppp?gmail?com)

* Inspired by alex's "64pixels" circuit.
* Some fun shots of TinyMatrix in the wild.

LED module is piggybacked directly on top of the microcontroller. 
This circuit will run off a CR2032 coin cell for days.
The middle 16 pins of the ATtiny4313 are GPIO, and will accomodate any DIP-package LED module.
I'm using a 12-pin Lite-ON LTP-747C.  LTP-757 family is also supported.
Other LED products may require source code adjustments.

    


Source code

    (see TinyMatrix.zip at bottom of page)

    Hex file is ~2000 bytes, leaving ~2000 free for additional images and animation code.
    One static 5x7 graphic occupies 5 bytes of progmem.

    Microcontroller runs at 4mhz, internal oscillator.
    Multiplex timing is handled by hardware interrupts, producing a very stable display.
    LED refresh: line rate = 390hz. Divide by 5 lines/frame = frame rate of 78hz.

    *update - Special thanks to Craig Lindley for providing a code update to
    display custom text messages.  See TinyMatrixScroll.zip at bottom of page. 

Schematic

    


Parts needed:

    ATtiny4313 - $1.51 each @ Digikey
    5x7 LED matrix (LTP-747 series) - $0.89 each @ Jameco
    100K resistor - $0.10 each
    Pushbutton - $0.25 each
    Coin cell holder - $0.79 each @ Jameco

    TOTAL COST: under $4 each (excluding batteries and programmer)

    


Assembly:

    No ISP connections are provided. Flash the chip first using a seperate programmer board.
    Trim in half all microcontroller pins except Vcc & Gnd
    Solder the power wires and pushbutton to the microcontroller, dead-bug style.

    

    Now piggyback the LED module, and solder to the 12 middle pins.

    

    Solder coin cell holder to power wires, which double as a necklace.
    Press the button to cycle thru different patterns.
    Remove battery to conserve power. 


Patterns

    SKULL HEART TREE
    DIAMOND CUP STAR
    BLOSSOM NUKE FOX
    INVADER 1 2 3 4

Animations:

    CHECKERBOARD (test-pattern)
    PSY-TUNNEL
    HEARTBEAT
    RAIN
    FIRE

To-Do:

    Sleep mode (aka auto-off)
    Add more patterns
    Add code to support other LED modules




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Tim Toner,
Oct 23, 2012, 1:59 PM
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Tim Toner,
May 22, 2013, 2:25 PM