arduino/bootloader
Simon M 1bf2f2a340 more bootloader notes 2021-07-27 21:48:11 +10:00
..
ArduinoISP.ino updated optiboot instructions, added 57600 baudrate 2021-07-27 21:33:59 +10:00
Makefile updated optiboot instructions, added 57600 baudrate 2021-07-27 21:33:59 +10:00
README.md more bootloader notes 2021-07-27 21:48:11 +10:00
optiboot_flash_atmega328p_UART0_57600_16000000L_B5.hex updated optiboot instructions, added 57600 baudrate 2021-07-27 21:33:59 +10:00

README.md

Regular Arduino firmware has a boot delay of over 1 second.

This directory contains a copy of optiboot for the atmega328p used in the Arduino Pro Mini.

First, if you don't already have one, create an ISP using a spare Arduino, following these steps.

Once complete, flash this optiboot firmware using the below command (on Unix, with avrdude in your PATH):

avrdude -v -v -c arduino -p atmega328p -P /dev/ttyUSB0 -b 19200 -U "flash:w:./optiboot_flash_atmega328p_UART0_57600_16000000L_B5.hex"

Or simply use the Makefile provided in this directory to execute the above command (again, on UNIX):

make bootloader

The bootloader was compiled using this repository.


For my own reference, the FTDI USB 6-pin pinout is:

  • Red wire 5V
  • Black wire GND
  • White wire RXD (connect to TX)
  • Green wire TXD (connect to RX)
  • Yellow wire RTS (connect to RST for code upload, disconnect to burn bootloader)
  • Blue wire CTS (disconnect)