I have a system that drives 300m of 24V LED strips. The strips are in 25 sections, each controlled by a MOSFET attached to an 328P.
When PWMing the strips (f=500-1000hz depending on the pin), the micros were becoming unresponsive. Suspecting it was a power rail noise problem, I connected the micros to a separate 12V power supply (all grounds are connected) and added a bunch of 100V 2200uF caps to the 24V supplies (as seen in the photo), some 470uF caps to the 12V rail, and some 100uF caps to the 5V rail of each board. This has seemed to help a lot.
However, every now and then, a micro still hangs. How can I further reduce the noise, and avoid a micro hanging?