Showing posts from August, 2017

Smart LED strips using a Blynk Interface

I recently decided that regular LED bulbs are too low-tech and non-computerized for my liking, so I decided to try designing a system that I could control remotely, for free, using smart WS2812 smart leds instead.

The Circuit I interfaced a small strip of 26 smart LEDs to an ESP8266 NodeMCU board via a 1K resistor, and powered the whole thing from a USB connection. Probably not a good idea at full power, so I made sure not to run the strip at full power. 
The Code The code for this circuit would be the most complex part, and I started by trying to get the ESP to control some smart LEDs. I did this by downloading adafruit's libraries and modifying their example code to do something really simple--wash some colors across the strip. This part of the code was pretty easy, although figuring out where the digital pin in the IDE linked to the physical pin was a little tricky. I found out that you could prepend a 'D' in front of the number to get the actual pin that was listed on …

Inductive Energy Transfer pt.1

For the next version of my crystal necklace, I wanted the ability to transfer energy to the device wirelessly, so that I could pot it in silicone and make it waterproof. In order to do that, I threw together a quick experiment using my function generator and an oscilloscope. 
Design I quickly printed out two spools with a diameter of 20 mm and wrapped 50 turns of 26 gauge magnet wire around each.

I then threw together a mosfet switch on a breadboard, and connected it to my function generator. I tried different frequencies with the device, and found that it transmitted best at around 2.18 Mhz.

I didn't bother measuring the power transmitted because it was so small, but I did manage to get a red led to glow slightly. I think I'm going to need to research this area more before I build the next iteration, and figure out how to push more power through.