What is it?
This is an accessory for the rotary encoder. There are 48 RGB LED disposed in a circle, the diameter of the circle is 40mm.
There is also a 9mm hole in the center where it’s possible to insert the rotary encoder. All the LEDs can be controlled individually with the i2c bus, the resolution is 24bit for each RGB led.
The controller is the IS31FL3737, it has several features like:
- 256 steps Global Current Setting
- Individual on/off control
- Individual 256 PWM control steps
- Individual Auto Breath Mode select
- Individual open and short error detect function
- Supply voltage range: 2.7V to 5.5V
It’s possible to connect up to 4 RGB LED rings on the same bus.
What makes it special?
There are several alternatives made with the WS2812, but the LEDs are big with a low density. The RGB LED Ring density is higher because it uses a 2x2mm RGB LED.
With 48 LEDs, it has exactly double of the number of the most common rotary encoders. In this way, it’s possible to make some effects without losing in resolution.
There are 4 SMD Jumpers where it’s possible to set the I2C address, only 4 combinations are possible.
It also has another SMD jumper where it’s possible to enable the pull-up resistor on the I2C bus.
The RGB LED Ring is compatible with the I2CEncoder V2.1 and the I2CEncodeMini
|VCC||LED supply voltage||2.7V – 5.5V|
|VIO||Logic supply voltage||2.7 – 5.5V|
|SDA||I2C data||Same as VIO|
|SCL||I2C clock||Same as VIO|
|INT||Interrupt output||Same as VIO|
VCC and VIO can be different, for example VCC=5V and VIO=3.3V. With VCC=5V and all the LEDs on the current consumption is around 450mA, make sure that you power supply can give that much current!
The documentations of the project is available on GitHub
There are the:
- Gerbers, BOM and pick and place
- 3D file of the board
There is also the Arduino library here with all the other DuPPa library.
The package includes 1 RGB LED Ring with a 30cm cable