White LED strip doesn't light up with arduino uno

Thread Starter

Ali Ashley

Joined Mar 18, 2016
4
Hi, Im looking to build a simple arduino circuit whereby a motion sensor turns a strip of LED lights on (one colour LED strip).

i have been able to successfully do it with a single LED light with and without a bread board and resistor, but when I tried to hook it up to and LED strip it simply didn't light up.

I then eliminated the motion sensing part of the circuit and again was able to light up a single LED but it doesn't light up the strip.

I have connected it via the barrel port to the wall wart and I'm using Arduino UNO R3.

Can anyone tell me what I need to do to get the LED strip to work with the arduino board. I'm using the gnd pin and pin 12 and its working fine to power a single LED, but what about a strip? Do I need a relay or a transistor?

Perhaps someone could draw up a circuit I could copy?
 

MrSoftware

Joined Oct 29, 2013
1,814
From memory; I believe the outputs on the Uno are not higher than 5v, and output current won't exceed 20-50mA depending on the voltage of the pin. So you're short on voltage, and looking at that LED strip I'm guessing it requires more than 20mA. I think you're going to need to use a transistor to power the LED strip, and use the Uno output to control the transistor. Maybe a logic level MOSFET. This one is overkill:

http://www.kr4.us/n-channel-mosfet-60v-30a.html
 

Thread Starter

Ali Ashley

Joined Mar 18, 2016
4
From memory; I believe the outputs on the Uno are not higher than 5v, and output current won't exceed 20-50mA depending on the voltage of the pin. So you're short on voltage, and looking at that LED strip I'm guessing it requires more than 20mA. I think you're going to need to use a transistor to power the LED strip, and use the Uno output to control the transistor. Maybe a logic level MOSFET. This one is overkill:

http://www.kr4.us/n-channel-mosfet-60v-30a.html
Thank you so much this helped a lot. I'm assuming from its capacities I will only need one?
 
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