Hackster is a community dedicated to learning hardware. Find instructions, connect with others, and get motivated to build better hardware. Join our community.

The UNO Overdrive

What to do when your Uno isn't fast enough

    • 2,814 views
    • 3 comments
    • 1 respect

    About this project

    The Overdrive

    What do you do when your project runs out of horsepower?
    Well you increase them of course.

    The Uno/Dumilanove Overdrive, running at 32MHz, makes your board and project go twice as fast.

    It replaces the existing crystal with a clockgen running at 32MHz for twice the speed.

    And it's 100% compatible and 200% the speed.

    That is a real speed upgrade.

    The Red Devil

    Why a clock generator?

    Because using a crystal at 32MHz won't work on the ATmega.
    Being spec to 20MHz It just doesn't oscillate at 32MHz.

    But a clockgen will force it to clock with is high output swing.
    So it runs.

    There is a drawback,

    It won't work at +70deg anymore.
    So don't use it in a car application.

    Needed changes

    For the timing to be correct you need to add a setting to the Boards.txt file in the ArduinoIDE.

    ##############################################################

    uno.name=Arduino Uno Turbo
    uno.upload.tool=avrdude
    uno.upload.protocol=arduino
    uno.upload.maximum_size=32256
    uno.upload.maximum_data_size=2048
    uno.upload.speed=230400 #For the original Uno chip use this
    #uno.upload.speed=115200   #For the Adaboot 328 chip use this one.

    uno.bootloader.tool=avrdude
    uno.bootloader.low_fuses=0xFF
    uno.bootloader.high_fuses=0xDE
    uno.bootloader.extended_fuses=0x05
    uno.bootloader.unlock_bits=0x3F
    uno.bootloader.lock_bits=0x0F
    uno.bootloader.file=optiboot/optiboot_atmega328.hex

    uno.build.mcu=atmega328p
    uno.build.f_cpu=32000000L
    uno.build.board=AVR_UNO
    uno.build.core=arduino
    uno.build.variant=standard

    ##############################################################

    The turbocharger

    How?

    The Uno/Dumilanove is set to use a fullswing external oscillator.
    That's a good thing because we can force the internal clock circuitry to run with our own TTL-signal. 

    We disconnect the Xtal1 and Xtal2 pins from the onboard crystal and feed our rail-to-rail 32MHz signal to the Xtal1 pin.
    The Xtal2 pin is left unconnected.

    Cut both the Xtal1 and 2 pins to the circuitboard because the crystal and capacitors will act as a filter on our new clocksignal.

    Schematics

    Comments

    dahans

    dahans

    over 1 year ago

    What Clock Gen are you using?

    Jan Ostman

    Jan Ostman

    over 1 year ago

    It's a standard 8-pin TTL chip. Anyone works

    great work thanks!

    Do something awesome

    Share

    Author

    Janne
    Jan Ostman
    • 11 projects
    • 14 followers

    Communities this project is part of

    Makers who respect this project

    Fc66f277801a02eaa5519c08c0998a22

    Other projects by the same author

    Most popular
    Most recent

    Published on

    January 11, 2014
    ProjectsPlatformsHardware WeekendHacker spacesBlogAdd projectSign up / Login