WiFi LED Driver

Simple; yes. Done before; yes. Entertaining to do myself; YES! Now… I just need that Photon to arrive!

This is my first post, so Hello World! I’ll probably come up with better stuff than this… but I’ve never used a Spark Particle product before! Very excited to see what I can randomly make.


What are you using for your LED driver?

I have made several LED fixtures with 3 and 5 watt LED strings but always struggle to find good driver options.

I’m building my own driver using the photon as the brain (turn on color, turn off color, adjust intensity - all via the PWM outputs). I’m switching 3 ZTX689B transistors for the different colors. I put in 3 diodes to be super safe with my photon. The other chip on the breadboard is just to go from 12V to 5V (Polulu D24V10F5) for the photon. Pretty simple driver circuit!

Welcome @kevinbragg and glad to see your enthusiasm! :slight_smile: Nice project and actually I haven’t seen it done quite like that yet, cool!

I am always concerned about burning the LEDs out so I want to incorporate current feedback measurement.

The fixtures I have built are for marine aquariums and are about 100 watts of real power not equivalent. So they take a bit of care not to overheat or over current them.

But like I said I am always looking for easier ways to do it

Rather than having intricate current monitoring circuitry, you could just fuse it! WRT heat, I’ve never worked with aquariums…

A nice blank space on the breadboard… just waiting!

So here’s the circuit I’m using. Great transistors that go into saturation at 10mA (instead of TIP31s @ >300mA… yah diodes gone). I’ve run this with all the lines full on and it pulls ~0.4A per line generating ~40C on the transistors and 60C on the lamp (LED radiant heat). Fortunately my Photons are “processing” so I should have this up and running this week.

Now I need to clean up the cell phone “app” (website).

1 Like

worked like a champ. YouTube demo later this weekend.

Hey this is awesome!!!

I am trying to do this exact project but seem to be staring at my computer screen completely confused!!

this colour picker is so cool! do you have any clues on where I can find or make one?

Thank you!

I’m about to go to dinner with my family. When I get home I’ll post the code.

I forget where I found this idea on Google, but I modified it to suit this purpose. I’m sure you could apply the same!


Thank you so much Kevin! silly question but did you basically have within one html the code for both the colour picker and the on and off buttons? this is all very new to me as you can tell.
thank you!

Yah. The LL.html was the color picker for my lamp. Then each additional light I have has its own ##.html. Then the root html has the on, off, and color (which loads the appropriate ##.html). And these websites are hosted on a BBB in my living room. I would have written an App for all this, but I’m not a CS and I’m on a Windows Phone… This was the easiest method I came up with.

Hey I’m having trouble linking to picker to the neo pixel led is there any chance you could send through your particle photon code?

Thank you!!

Of course. I’ll upload when I get home (20 minutes.)


Did you get it working?

Worked like a charm! Used 470 ohm resistors & 2N4401.
Code has a on-off flash to it. …and I disabled the manual reset as I wasn’t using it.

Thanks for posting this!

Edit: need to watch how much current is running through the 4401s. They are a bit small for a full strip of LEDs.