Hi Ray,
Thank you for the fast reply. I read the message “Note that OpenSprinkler does not use a bootloader, so please do not upload any bootloader to it.” on the firmware update page, and thought that there was no boot loader required. I’ll program optiboot using ISP port using a USBasp. Can you please confirm that the 2.2u Nov/14 hardware uses a 16MHz Xtal for the atmega (X0).
Thanks again,
Regards, Bruce