- Simple hardware, using pre-fabricated modules
- Controls an RGB LED via any recent browser, any operating system
- WiFi credentials can be configured via browser
- Software is written as an Arduino sketch
Some time ago I read about the cheap and easy to use ESP8266 WiFi modules and I had to have a couple of them. So I ordered two ESP-01 modules. At the time I had no idea what to do with them, but I was sure that this was only a matter of time.
Later, I discovered that high-power LEDs can be had for a ridiculously low price from China, so again, an impulse purchase was the inevitable consequence. Of course it was soon clear that I had to combine both..
By the time that insight dawned on me, the community had made major advances on the IDEs for the ESP8266. Whereas earlier you had to use a separate microcontroller and communicate with the ESP via UART and AT commands, it is now possible to use the Arduino IDE. This is an amazing and fascinating development and I decided that I would build a WiFi controlled power LED without a separate controller. After all, setting a few outputs to PWM is easy, right?
I was pretty confident that the hardware side of things would be trivial. I needed a 3,3 Volts power supply for the ESP, and a few transistors to drive the current for the LED. That would be more or less it.
And of course this went wrong – at least to begin with. The LED that I intended to use was advertised as a “high-power super bright RGB LED” with the following technical data:
- Power: 10W
- Voltage: Red 6-7V; Green 9-12V; Blue 9-12V
And that was all. No data sheet, nothing else. But how could that stop me with a price tag of €1.20?! From other, similar offerings I learned that this variety of LEDs should be fed a current of 300 mA. That sounded reasonable to me. It meant that each colour was contributing about 3 Watts to the total sum of 10 Watts. And the high voltage meant that for each respective wavelength, three LED chips were connected in series.
Read more: WiFiRGB – A WiFi-enabled RGB high-power LED