First Experiments with RGB and ESP32

The past few days, I’ve been experimenting with both RGB LEDs and ESP32. I’ve never worked with either before, so I wanted to get some experience with the basic functions before I dove into the more complex task of building the hamstercage lighting.

My first experiment was trying to get the RGB LEDs working. I have a strip of 60 WS2812 RGB LEDs, which are one of the apparently two common types of RGBs. The WS2812 distinguish themselves by having some manner of IC included in the strip, so that there’s a single data line in along with the power and ground, making coding quite easy. The other most common RGB strip also includes a clock signal, so that still seems fairly elementary. To get this working, I hooked it up to my Arduino Uno clone, added the FastLED library, and loaded up the first couple of examples. Everything pretty much worked without a hitch, which was great. About the most complex part was that the examples mostly used pre-defined colors (::red, for example) whereas I potentially want to use a whole host of RGB values. However, one quick online search and that was already solved.

ESP32, however, was a little more tricky than that. My first very practical problem is that the breakout board is just slightly too big for my breadboard. I can only just about fit it on one, leaving a single row of headers for additional pins. Nevertheless, that’s all we need to test the single RGB strip. The bigger issue was trying to figure out the pin-outs of this board. There seemed to be a number of potential pinouts provided online, and they just didn’t seem to work for me. In fact, nothing worked until I switched to a different example – I guess I must have messed something up in the example, causing all my other issues! Once I fixed that, the pin-out diagrams seemed to make sense again, so that was one hurdle taken.

However, somewhere in this testing, I seemed to have messed up one of my ESP32-WROOMs. I’m not too sure what’s going on, but it’s no longer registering on the USB port. However, I’d bought three of the chips (potentially for three separate parts of the cage, though I appear to not need that), so a secondary one took its place. I’m noticing that the problematic ESP32 has a rapidly blinking LED, which may be a hint to its condition. If I press the boot and enable buttons at the same time, I can upload a program again, but as soon as it’s reset, the chip seems stuck again and the LED is back to blinking rapidly. It’s possible that while I was probing the board with my multimeter, I may have shorted something, I’m assuming. However, for now this will remain a mystery.

Having tried out the basics of RGB LEDs and the ESP32, and being able to light the LED strip with any RGB value, I have two of the three fundementals ready to work on my hamster cage project. The last one is a way to control the lights. The most basic option is to provide some physical controls at the cage. This is quite sensible, as there’s no need to control the lights unless we’re at the cage doing something. The second option is to use Blynk. Blynk is some manner of visual app development program that has interface possibilities with ESP32 chips built-in. It seems like an easy way to make an app, but it also comes with a rather limiting fremium model that I’m not a fan of. We have the features that it offers right now, but how long before those become premium features? The last option is to personally write some manner of HTML interface. I’ve looked into it, and making an elementary one doesn’t seem too complex. The most difficult parts (having a slider for the RGB colors, for intance) are already worked out in basic java snippets available on countless forums. I like the home-made aspect of that, though it may make the controls a little less polished.

I’m not too sure what route I’ll end up taking but whichever route it will be, my next step has to be to control the color of the LEDs live in some form or another.

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