Good evening everyone, I'm really in trouble, I have an exam tomorrow and I can not run my LED matrix. please I need help immediately!
I have mega Arduino 2560 with an external power supply from 7.5V, and above it says (PRI: 100V-240V ~ 60/50Hz 350mA SEC: 18V 1500mA 3/4.5/5/6/7.5/9/12V) to connect a perforated board 28 series resistors connected to GND, the resistors are 220-hom. and on the other hand there is 5V. this is attached a button that illuminates a LED and a cable that goes into a pin of Arduino. my problem is that I have 28 buttons / LEDs, and they attack more than 4 of the Arduino board is really hot and I'm afraid to melt! I attach a picture, I hope is clear.