I have a very small program that, when power is turned on, it runs a few measurements and then turns the power to the board off. In the two pictures below I show the results I get with the program run on a Nano and an Uno (voltage to the board vs. time). As you can see, the Nano is almost 4 times faster than the Uno to complete the cycle. I am just curious, what IC component(s) on the Nano makes it so much faster? In terms of specs, I always viewed the two as equals. But something is clearly different.
They may have different bootloaders.
removing the bootloaders and programming your sketch on them via the ICSP header may make them startup instant.
The "optiboot" loader does not wait for a possible software upload on power-up, only on a reset after power-up.
Great! I will have to experiment with these loaders and see if they make a difference. First I just need to get the proper cables etc. Great ideas! While I think 0.5s is very fast already - even faster boot-ups would be nice as that would conserve energy in my project. I thought this was hardware limited. Seems not then. Thank you!
Sketches uploaded via ISR ISP have no bootloader to clear. They hit the ground running.
runaway_pancake:
Sketches uploaded via ISR have no bootloader to clear. They hit the ground running.
ISP ?
"ISP ?"