I need to have the project completed by Thursday morning!
Battery needs to power:
40 WS2801
Wemos D1 mini
MSGEQ7
I think I will be able to just supply power to the MSGEQ7 from the 3.3v on the Wemos mini?
My current progress on the project. Tomorrow I will be “setting” the leds in the spoke holes. I just need to drill out the spoke holes some more first. They will alternate, pointing inside and out.
Your LEDs are 5V you have to ‘burn’ 7V - that’s nonsense. Look at the LimeFuel Blast what @Devon_Meyers posted a few entries down.
If you HAVE TO use 12V then buy at least 2 LM7805 with 1.5A output (they also come with 1A)
and power 20 LEDs each from them. Don’t connect the 5V side together! …and don’t forget good heat sinks because they’ll get toasty.
Powering the MAGEQ7 from the Wemos should be no problem.
Don’t go anywhere near a linear regulator. They’re really only any good for things that are drawing very small amounts of current. You’ll be much better served using a buck converter of some form. They’re also called dc dc converters. The first link in these comments is a buck converter.
I’ve no idea about what suppliers are good to use in the US (I’m guessing you’re there.) Looking on Amazon I found 2 that would fit your needs.
Linear regulators make the voltage they need by burning off the rest as heat. In your case, that could mean you’re wasting up to 16.8 watts of energy as heat, which is a waste of power and also means you need to shell out for heatsinks if you want your regulator to survive.
Buck converters use trickery between an inductor and diode to convert the voltage down. They can achieve up to 90-95% efficiency. In this case, a linear regulator would be getting 42% efficiency.
So this looks like what I would need! So I could go battery -> buck converter -> wemos mini 5v pin and WS2801s (wemos and ws2801 would be wired in parallel?)
I am guessing it would be fine to keep the converter with the battery “off site” and not on my rim?
Look at the reviews and carefully check the output voltage before you hook up the LEDs.
When someone reports a humming noise out of his radio the red flag goes up!
One 1000 µF is fine but also add a few much smaller values such as 100nF, 1µF and 100µF for the faster transitions.
For this part a 5.1 V Schottky Diode as additional voltage regulator seems to be a good idea.
Okay, I will keep trying to do research. This part is over my head and time is running out! Last night I got the lights mounted, and my code is moving along well
@Andrew_Watts Testing the dc dc converter last night, output voltage seemed ideal. I did notice the converter quickly heated up, is this to be expected? In my test, I just had input hooked to the battery and then I was just using my multimeter to measure the output. If this seems normal, maybe I can have the converter mounted directly to the bicycle rim. Then the rim can help dissipate some of the heat?
