If you like LED clocks and illuminated bicycle wheels, [Harald Coeleveld] has just the right weekend project for you. His RGB pixel LED clock is as simple as it is beautiful, and it can be built in no time: The minimalist and sporty design consist of not much more than a LED strip wrapped around a bicycle wheel rim.
[Harald] took 2 meters of addressable WS2812 LED strip (with 30 LEDs per meter, we assume), wrapped it around a 27″ bicycle rim padded with a foam strip, and obtained 60 equally spaced RGB LEDs on a ring, ideal for displaying time. Apparently, the rim-tape circumference of this particular 27″ bicycle wheel is close enough to 2 meters, so it lines up perfectly.
On the electronics side, the project employs an Arduino Nano and a DS3231 precision RTC module. For switching between two illumination modes for day and night, [Harald] also added a photoresistor. During the day, colored dots around the ring display the time: A red dot for the seconds, a blue one for the minutes, and a group of 3 green LEDs for the hours. At night, the entire ring shimmers with an effective red glow for easier readability.
The Arduino code for this build can be downloaded from the project page, enabling anyone to effortlessly replicate this design-hack in under an hour!
I love clocks. This is awesome and I want to make one now.
that is pretty neat.
Foam, it’s a clock all on it’s own. It’s timed to self destruct into either goo or crumbles.
I was actually considering making essentially this exact project (minus the bike rim). I was considering using an ESP8266 so it could sync w/ ntp and be minimal.
I know that the Teensy can drive those LED strips really well due to the DMA channels and timers. Can the ESP8266 be similarly efficient?
I made something like this a while back, with an added effect, I made each “light spot” larger than the physical pixels, so that they could gradually brighten and dim ahead and behind each virtual clock hand. Also, when the “hands” overlap each other the colors blend realistically.
It looks like he’s using the older FastSPI_LED library instead of FastLED. The newest supports WS2812, I’m curious if there is something the new version breaks or doesn’t support that’s being implemented.
Nvm, I hadn’t scrolled far enough.
Code listing for NTP using a NodeMCU ESP8266 ESP 12E:
https://coeleveld.com/nodemcu-esp8266-esp-12e-v1-0-clock/
Needed to use NeoPixelBus library using DMA as bit-banging (Adafruit Neopixel / FastLED lib) is sensitive to interrupts of Wi-Fi housekeeping. Didn’t need level shifters for 3.3V to 5V logic. 3 meters of 4 strand RJ11 telephone line wire as data line (and power supply) to LED strip. Bit less stable than Arduino with slight hint of flickering, but okay.