Arduino Mega not powering on

Using Arduino LEDs and Multiplexing
1

Hi guys,

I'm new here and didn't find any solutions to my problem. I hope I'm at the right place. Maybe some of you could help me.

I'm trying to create a MIDI controller using an Arduino Mega with a Mux shield II (for additional inputs/outputs) and an expansion board Sensor Shield V2. All pins are used, I have:

  • 2 joysticks
  • 2 hall effect sensor
  • 22 potentiometer
  • 37 LEDs
  • 10 switches
  • an old telephone (I'm going to use the telephone pad as MIDI buttons)
    It fills up the entire Sensor Shield and 2 full lines of the Mux Shield.

After wiring everything, I plugged via USB the arduino and it lit up for like 2 seconds before having the lights (TX/RX/Power ligh) fade off. I tried adding a 9V/2A power supply and it didn't change anything, the arduino lights up for 2 seconds and turns off.

Any idea how to solve this problem ? I probably missed something here. Would be so grateful to anyone here having a solution !!!

2

Could you provide schematic of your setup?

3

Obviously something is requiring more current than the USB can provide. You need to figure out what that is.

Do not attempt to use the "barrel jack" or "Vin" to power a project - they are useless ornaments. :astonished: You need a 5 V regulated power supply rated for the required current draw.

4

On USB supply you theoretically have 500mA (polyfuse limit) - 70mA (Mega self-draw) = 430mA to play with.
With 9volt on the DC socket (8.3volt on V-in), you theoreticlly have 1.5 / (8.3 - 5) - 0.070A = 385mA to play with.
Assuming the slightly bigger 5volt regulator of most (not all) Megas can dissipate 1.5watt.
No matter how big your 9volt supply is (current), you can't push more than through the Mega before the regulator overheats and shuts down (if you're lucky).
Leo..