Marlin Disable JTAG

Good morning dear community:

I have a question just downloaded the new marlin v1. reading some of your information, says it has disabled the JTAG FUSE causing problems with this statement is true ATMEGA1284P ?. If true as I can do to use this option and so to give my Sanguinololu 1.3a functionality card that I have long ago.

thanks for your prompt replies.

yes the jtag has to be disabled on atmeg1284p also if used in a standard reprap. The pin are used as normal IO pins. normally end stops and x direction lines

Hi! Dust thanks for your answer, but could you explain how it should burn the bootloader and firmware to atmega 1284p but please could you explain how it should burn the bootloader and firmware to atmega 1284p because the truth could burn the bootloader and firmware and when testing X axis move in one direction, limit switches fail to trigger.
I don´t know where I am making the mistake

When you upload the boot loader with the Arduino IDE it also sets the fuses. these are bits that enable and disable chip features, such as jtag.

You must have added the 1284p chip type to the IDE by adding some files. One of the files is
hardware/sanguino/boards.txt

In this file is something like
atmega1284.bootloader.low_fuses=0xFF
atmega1284.bootloader.high_fuses=0x9A
atmega1284.bootloader.extended_fuses=0xFF

These are the fuses..

For a Sanguinololu the fuses need changed as it has a resonator not a crystal and to disable the jtag

to

atmega1284.bootloader.low_fuses=0xD6
atmega1284.bootloader.high_fuses=0xDC
atmega1284.bootloader.extended_fuses=0xFD

Update the boards.txt and rewrite the bootloader

Edited 1 time(s). Last edit at 09/27/2014 07:44PM by Dust.

you may need to redo the boot loader code to the board. if you have another arduino you could do arduino boot loader, or you could try bitbanging. if you dont know what that is it is best to use another arduino to program.

read tutorial here.

[arduino.cc]

and here

[reprap.org]


and here for 1284p

[ryanmsutton.com]

and this info on reprap forums [forums.reprap.org]

Edited 4 time(s). Last edit at 09/27/2014 10:07PM by jamesdanielv.

thanks for your help!!