Wouldn’t it be fun to add bright, beautiful NeoPixels to your Raspberry Pi project? However NeoPixels, and the WS2811/2812 LEDs that make them up, require a data signal with very specific timing to work correctly. Because the Raspberry Pi runs a multi-tasking Linux operating system it doesn’t have real-time control over its GPIO pins and can’t easily drive NeoPixels. Typically a small microcontroller like a Trinket or Teensy can be used to communicate with the Raspberry Pi and generate the NeoPixel data signal. However thanks to the excellent rpi_ws281x library created by Jeremy Garff, you can now control NeoPixels or WS2811/WS2812 LEDs directly from your Raspberry Pi!
Jeremy’s library solves the real-time control problem by using the PWM and DMA hardware on the Raspberry Pi’s processor. The PWM (pulse-width modulation) module can generate a signal with a specific duty cycle, for example to drive a servo or dim an LED. The DMA (direct memory access) module can transfer bytes of memory between parts of the processor without using the CPU. By using DMA to send a specific sequence of bytes to the PWM module, the NeoPixel data signal can be generated without being interrupted by the Raspberry Pi’s operating system.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.
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