ESP8266 APA102 Bulb
Published
As an experiment in HW design an alternative to the Philips Hue was built. It's fully programmable over WiFi.
The product of this project is a WiFi connected LED bulb. Every LED on this bulb is individually programmable over the WiFi, by simply sending UDP packets to the bulb.
Software and hardware sources
git clone https://github.com/robertfoss/esp8266_apa102_bulb.git
This project consists of 3 parts: the software running on the led bulb, the software running on some host computer and the hardware.
Firmware
The firmare is based on the NodeMCU firwmare for the ESP8266. It's running the APA102 LED driver and the enduser setup module, which I've written about previously.
Additionally it's running 3 lua scripts that deal with different aspects.
There's init.lua which makes sure we're connected to a WiFi.
udp_listener.lua receives UDP packets and then sends forwards that data to the APA102 strips.
And lastly udb_broadcast.lua which periodically broadcasts a heartbeat for this LED bulb to signal that it is alive and well.
Host application
The current (as of the publish date of this post) incarnation of the host application listens for bulbs that are alive on the hosts network. If a bulb is found is will be added to the list of bulbs to be animated. All animations are simple and sinusoidal and only use the time a bulb has been 'alive' as an input for the animation.
Hardware
The hardware is based around the ESP8266 WiFi IC and the APA102 SPI LED IC.
The flavor of ESP8266 used in this project is the ESP12-F module, since it the latest module available with the integrated antenna form factor.
APA102 was chosen instead of the much more common WS2812B chip, since it uses a SPI like protocol which isn't timing sensitive and also does not require external capacitors at next to each LED.
v3.1 Schematic
v2 3D Model
Assembled v2 hardware
