What is it?
The F40D-PB is a cape for the PocketBeagle designed to drive ws2811 LED pixels. It also has 10 RJ45 differential ports that can output 40 strings of pixel data. Two of the RJ45 ports can optionally be configured to output 4 universes of DMX instead of ws2811 pixel data.
The F40D-PB also provides a Real Time Clock, temperature sensors, a header for an OLED display, and two push buttons for navigating menus on the display.
Why did you make it?
Animated Christmas Light displays typically use ws2811 Pixels for things like house outlines, candy canes, tree’s, etc… The F40D-PB was designed to drive a large number of pixels, yet remain relatively small so it can be easily hidden or mounted onto the prop.
What makes it special?
The 10 RJ45 ports provide the ability to drive a ws2811 pixel differential receiver board (available from pixelcontroller.com ). 2 of the ports can be configured to output 4 universes of DMX for each port.
The F40D-PB must be powered by an external 5V power supply through the screw terminals on the board.
Technical details: Both the DMX and ws2811 protocols are extremely timing dependent and are generally not drivable via a general purpose Linux CPU. The FPP software uses the two semi real-time PRU’s available on the PocketBeagle to handle the protocol specific timings. One PRU is used for the ws2811 protocol strings and the other PRU is used for the DMX timings. Using the PRU’s also allows the main CPU to be free for other things such as network IO.
You WILL need:
- ws2811 pixels
- Differential receiver boards
- A good quality SD card with the latest FPP image installed on it. The latest FPP image can always be found at http://dankulp.com/bbb/
- A USB network adapter – ethernet is preferred for initial setup, but WIFI (adapter must be supported by Linux/Beaglebone/Raspberry Pi) can also work if you use a micro-usb cable to connect to the PocketBeagle to do the WIFI setup.