I am having issues with uploading sketches to a bare SAM3X chip. I have my hardware configured like the USB programming port on the DUE, using an Atmega16u2 interface. I've programmed the 16u2 with the avrisp mkii programmer, with the firmware found here: https://github.com/arduino/Arduino/tree/mas…

Programming Bare SAM3X Chip

Palliser November 28, 2012, 1:00am 2

I would recommend you to try the firmware for DUE contained in the Arduino IDE 1.5.1r2

...\arduino-1.5.1r2-windows\arduino-1.5.1r2\hardware\arduino\sam\firmwares\atmega16u2

Topic		Replies	Views
Programming problems on Arduino DUE DIY board Project Guidance	11	2829	May 5, 2021
Programming SAM3X from 16U2 IDE 1.x	1	430	May 5, 2021
Due derivative without Programming Port? SAM3X Erase, Bootloader? Arduino Due	5	4268	May 6, 2021
DIY Arduino due board can programming but nothing work on SAM3X Arduino Due	10	3920	May 6, 2021
Upload DUE skteches to SAM3X chip not on DUE board ? Arduino Due	4	1071	May 6, 2021