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Topic: Arduino r3 uno - gregensom dancing LED strip project (Read 546 times) previous topic - next topic


I am completely new to arduino and want to follow a YouTube called gregensoms guide to making interactive LED strips:
His video is awful when it comes to teaching how to actually make it. On his GitHub i found the schematics code etc. I understand majority of the circuit except for how to connect the LED strip to the arduino, and how to power it? i.e. do i connect the strip to the arduino and plug a 12v supply into the arduino? i dont get it. Could i have links on amazon uk for the power supply required, and some advice on how to actually connect it? thanks :D


Jun 09, 2019, 06:52 pm Last Edit: Jun 09, 2019, 06:52 pm by Grumpy_Mike
Truly appalling video. With quotes like "I really don't know what is going on here I will have to work it out."

On the schematic on the video he shows a 12V power supply being connected to a 5V strip which will burn it out if you try it.

He shows two sorts of strip in the video's notes.
LED Strip (12V): https://www.amazon.com/BTF-LIGHTING-3...
LED Strip (5V): https://www.amazon.com/gp/product/B01...

So if you have the 12V one power it with 12V, if you have the 5V one then power it with 5V. If you have the 12V one then in the code where you specify the number of LEDs then you have to use a number that is one third of the number of LEDs you actually have, because those strips only control the LEDs in groups of three at a time.

On his GitHub
Would have been good to provide a link to that.




that's his GitHub ^

i will opt for the better led strip:


what i dont understand however, is how do i connect a charging pin from the 12v power supply to the circuit?
i know the arduino has a power supply input, but the led strip needs an input. how do i do the wiring?


Jun 10, 2019, 12:50 am Last Edit: Jun 10, 2019, 12:54 am by Grumpy_Mike
i will opt for the better led strip:
Is that better? I would have said not because you can only change the LEDs in groups of three. Still as it is 12V already then you feed your 12V power supply into both the LED strip and the barrel jack of the Arduino. The inbuilt regulator will take this down to 5V and you are not trying to power much else through that regulator.

is how do i connect a charging pin
What is a charging pin?

That Git hub page is worse than the video. Do not follow that schematic it is all wrong.


I am really keen to make these LED strips, so is there anyway you can provide any help? i honestly have no clue with what im doing. In my life ive only ever used picaxe chips eg, 14m2, and they are far more simple. Can you take me through how i should go around doing this?

i have attached the schematic of what i was going to follow

thanks :D


First off the strip needs a resistor in the data line and a capacitor across the power supply like this:-

Then if you are using a 12V strip, that image that says 5V on the strip needs changing, because that will confuse the hell out of anyone who sees that diagram. Then you need to connect the ground of the 12V power supply to the ground of the Arduino. Also make sure the capacitor you put on the strup is rated for 16V or higher.

I would also go to the schematic tab of Fritzing and create a proper schematic, what you have is just a physical layout diagram which is useless for anything but mindlessly plugging in wires. In fact what I would really do is to ditch the Fritzing all together as it is a pile of crap.


Hey mike,
by the ways i want to thank you so much for being so persistent with me. I understand the whole resistor story as im not a complete moron. What is that adapter for the 12v power supply called? thats basically what was completely confusing me.

What components would you recommend? And what am I missing. the arduino kit has a lot of stuff in it including resistors, however, 470 is not included.

ill link what i have chosen:





What is that adapter for the 12v power supply called?

Note there are two types 2.1mm and 2.5mm. This is the diameter of the central spike, make sure you get the one that suits your power supply.

You will need a 12V power supply with a capacity of at least 6A unless you limit the brightness in software.

however, 470 is not included.
Anything from 200 to 510 will do. So use a 220 or two 220s in series to give you 440.


Would this power supply be enough? it also includes the adapter.
Im ready to order, but now what is confusing me is:


I dont understand how to connect the one power supply into both the led strip and arduino, as the arduino also requires power. do i need another power supply? what's the easiest way.

also with the diagram i sent you thats full of errors, from the youtube video, how to i wire in the petentiometers because for 2 of the 3 wires going into the petentiometers, they are going to the same port on the arduino.

mike: do you have Skype or any sort of means on which i can communicate with you more easily as im still very confused with how to power this, and i doubt its any easier to explain. I am on a budget of a maximum of £35. Ebay have very cheap arduinos etc


Ok you seem to have changed the sort of LED strip. That strip is not suitable for your project.

I dont understand how to connect the one power supply into both the led strip and arduino, as the arduino also requires power.
You put two wires in each of the screw connectors and connect one set of wires to the strip, and wire either a barrel jack into the other set of wires for connection to your Arduino, or wire into the Vin pin and ground of the Arduino. To make a proper connection you will need a header strip so you can solder the wires to it and then plug the header into the Arduino's header sockets.

You can wire a short length of wire from the header socket and strip it back at the end and wire many other wires into that point.

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