# Variable intensity for +/-200 led

Hi!

I'm a beginner in arduino, I've studied some programming for my study but this was not really for electronic use, it was more for industrial program or ladder one.

I've done some project on arduino like using a switch level to my reverse osmosis, and some other thing kinda just fun as lcd touch display.

Now I have a new project for a friend's car, it's would be to put a lot oh led in the rear light (brake, tail light, reverse). I've seen some on some new car and found that it was pretty sick, here you can see an example of what, I'd like to do, perfectly but for the beginning, it should be only a brake dimming light (2 level) and a little moving if it could be implemented: https://youtu.be/YMZUKWtS4kQ

In the perfect case that would look like this. If done some search but as I'm not fixed in the number of led, the size, but I was thinking for about 1-200 minimum of 5mm red led ?

My search wasn't really concluded because I only found matrix pr pwm high power led which isn't my case :/ So to recapitulate I need to manage a lot of led, one by one and with different intensity, maybe 2-3 level will be enough.

Finally, to make the traveling effect, is there any functions to do this expect writing line by line every led to be one or off ?

Sorry for my nooby question as I'm not really formed for electronic application.

Thanks in advance

Go to ebay, and enter “8x8 LED matrix”.
The single ones with 64 LEDs and a driver chip on the back are about 2\$.
The chip does all the work, including intensity.
This one is a (fixed) block of four. Nice to start playing with.
They (all modules in a string) use three pins of the Arduino, plus 5volt and ground.
There are many 8x8 LED matrix threads on this site.
Leo…

Finally, to make the traveling effect, is there any functions to do this expect writing line by line every led to be one or off

Yes, you can either define the sequence algorithmically, or define the patterns in a data structure or look up table.

I would use the Neopixel strips from Adafruit, simple to wire up and control, your big problem is getting the 5V to power it all.

Hi!

I didn’t know about these matrix, this should be a really great idea !

I’m just bidding some of it to try and my own purpose !

I was thinking that it only use led for on/off not really variable intensity hmm…

Going to search some of it but with this max7219 I can see pretty much information about it.

Yep for the algorithm, but for some maybe complicated one, it’s not the easier solution for the future maybe ?

For the power, I’ll use the 12v from the car battery… And for all of these led… Maybe a buck puck for that amount of current ?

There are MAX7219 libraries that can do the heavy lifting for you.