I have a Mega project that runs off an external, 12v 10A power supply. The same power supply controls a few meters of 5630 LED strips, hence the high amp rating. I have the 12v going to the Vin on the Mega and the project works fine for the most part, however when it executes commands, the display (1.8" TFT) flickers. Occasionally it will just terminate the command and reboot. However if I have the USB cable connected to the Mega at the same time, there are no issues at all. That leads me to believe that somehow the external power supply is insufficient to power the lights and the Mega (plus attached devices).
My thoughts on solutions are to build a voltage regulator circuit that steps down the 12v to 5v and supply that through the 5v pin, but then I’d have 12v going into Vin and 5v going into the 5v pin at the same time. I’ve attached my schematic, however take it with a grain of salt because it is not up to date. The wiring from the power supply to the board and LED strips, however, is accurate and has not been changed.
Any ideas on what might be causing this insufficiency in power? Thank you.