E13
WS28xx - MPX
Abstract: WS28xx compatible multiplex LED driver (charlieplexing) with variable voltage.
Specs
This module implements a 12 channel WS2811 emulator to drive multiplex (charlieplexing) signals. The number of LEDs is auto detected. The E13 may be cascaded with WS2811 (or compatible) chips.
Features,
- Variable (auto detecting) LED count [0..12]
- Screw connectors and 2×2 (2mm) connector
- Variable LED voltage [2..5V] for global dimming
- 256 step PWM (300Hz) per LED
- Multiplex driver
- Gamma correction (optional via firmware)
- Connects to C30, C23 or C19 modules
- Fast firmware update via RS232 debug interface
Note: The E13 may also be used with other WS28xx compatible controllers such as MobaLedLib (not been tested yet) or BiDiB NeoControl.
Most LEDs are very bright when used at 5V. To limit the maximum brightness, it could make sense to lower the common voltage to e.g. 3.5V. In this case, the value for common must be 178.
Common[Volt] = 5[Volt] * {common} / 255The common voltage scaler can also be used to adapt to the day/night operation of the system. Adequate LED intensity may be too bright if the system is operating in the dark.
The number of LEDs is detected automatically (n = number of detected LEDs which can be zero),
WS28xx bus: … {common} {led_1} {led_2} … {led_n} …
Example
Here the E13 module is used to drive multiplex signals. The C30 is a quadruple signal controller, each connecting to an E13 generating the Multiplex signal for the LEDs. Technically, the E13 can replace standard WS2811 chips.
Gallery
