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Atmega328 Bootloader For GRBL

Discussion in 'General Talk' started by Kyo, Oct 31, 2016.

  1. Kyo

    Kyo Master
    Staff Member Resident Builder Builder

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    Just a configured version of Optiboot 6.2 disabling the flashing led on D13 during power up..

    Place the two files included so named "optiboot_atmega328_d13_led_off" into your Arduino Optiboot folder under hardware. ( Folder location is dependent on OS )

    Add the following board to your boards.txt file.

    Code:
    grbl.name=Atmega328p for grbl
    
    grbl.upload.tool=avrdude
    grbl.upload.protocol=arduino
    grbl.upload.maximum_size=32256
    grbl.upload.maximum_data_size=2048
    grbl.upload.speed=115200
    
    grbl.bootloader.tool=avrdude
    grbl.bootloader.low_fuses=0xFF
    grbl.bootloader.high_fuses=0xDE
    grbl.bootloader.extended_fuses=0x05
    grbl.bootloader.unlock_bits=0x3F
    grbl.bootloader.lock_bits=0x0F
    grbl.bootloader.file=optiboot/optiboot_atmega328_d13_led_off.hex
    
    grbl.build.mcu=atmega328p
    grbl.build.f_cpu=16000000L
    grbl.build.board=AVR_UNO
    grbl.build.core=arduino
    grbl.build.variant=standard
    You can now burn your atmega328p bootloader with the Arduino IDE ( I used 1.6.12 ) If your running a Nano with 328p chip it will now act like a Uno. (smaller bootloader :) )

    The main reason to use this bootloader vs a standard install of optiboot; Will be led on pin D13 is no longer going to flash at power up or reset. If you have a relay with say a spindle attached to D13 the flashing of the led could cause it to turn on before being told to do so with G-code commands.

    I used a Arduino as ISP ( changed heart beat delay in isp sketch from 40 to 20 ) and Arduino IDE 1.6.12. This bootloader is for Atmega328P chips. Use at your own risk.

    Compiled from Optiboot source code 6.2 Using the " make LED_START_FLASHES=0 atmega328 " command
     

    Attached Files:

    David the swarfer likes this.
  2. David the swarfer

    David the swarfer OpenBuilds Team
    Staff Member Moderator Builder

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    Since I have an USBasp I have been thinking to just burn GRBL directly without a bootloader at all.
     
  3. Kyo

    Kyo Master
    Staff Member Resident Builder Builder

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    That works to :thumbsup: Not really a need for a bootloader other then using the usb for updating grbl and you can use the usbasp for that..
     

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