I am using an Arduino Mega, and wish to make the bootloader-caused initial startup delay to be as little as possible, at most 0.5 seconds = 500 milliseconds. That is, so that my sketch runs as soon as possible (whether when first powered on, or when reset).
Could someone get me started on how I would go about approaching this, assuming this is doable?
Get an AVR ISP, such as Atmel AVR ISP MKii
Then use File:Upload Using Programmer to down your sketch with no bootloader. Sketch starts immediately after reset.
NickGammon has great web page on using arduino as a programmer also.
Need someone knowlegdable in making the bootloader to answer that.
But really, when you come up with the means to install a revised bootloader, then you have the means to use File:Upload Using Programmer, so why not use it?
CrossRoads:
I'm sure there is - the current delay is in there, yes? So likely it can be shortened.
Someone like westfw has the knowledge of what goes into it.
(I concur with the ease of the ISP-based upload, and have used it in the past, but I'm much more curious how the bootloader itself can be modified to solve the problem. And if I could set a 0.5-second wait time, that should be enough for waiting for the serial data, no?)