I am using an adapter (12 VDC, 2A) and I want to be able to power an LED strip with it plus the control circuit.

The problem is that the Atmega328 reboots, but when I only power up the LED strip with that adapter and power the control circuit with an independent 5 V adapter everything seems to be alright.

I can't do that in real world; I need to ude the same adapter.

I attached a picture of what I am doing right now. Please help me fix this.

I am using a 7805 regulator to reduce the 12 V to 5 V.

enter image description here

  • How much current does the LED strip use?
    – ocrdu
    Nov 14, 2020 at 15:29
  • What do you mean by "the Atmega328 reboots"? When exactly does it reset? And have you tried putting a big capacitor between the power lines of the LED strip? Changing the strip state also influences the power draw. When the strip suddenly draws way more power, the power supply might produce a short dip in voltage, which you can smooth out with that capacitor
    – chrisl
    Nov 14, 2020 at 15:31
  • And what kind of strip are you using? How exactly are you controlling it? Please show your circuit.
    – chrisl
    Nov 14, 2020 at 15:32
  • what exactly is your question? ... you did not actually ask one ... more than one question could be asked
    – jsotola
    Nov 14, 2020 at 18:39
  • easy: you need a dc adapter with more amps.
    – dandavis
    Nov 14, 2020 at 20:21

1 Answer 1


Why not use the barrel input connector and input 12VDC there, the filtering etc on the board will help. Also as dandavis stated you need a bigger power supply or remove about 1/2 of your LEDs.

  • what barrel input?
    – Juraj
    Jan 4, 2023 at 18:31
  • Without the "Schematic" (picture) how would you answer it, they were not when I answered it. You might also look at the dates.
    – Gil
    Jan 6, 2023 at 21:38

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