In this episode Shahriar takes a close look at programming the popular NeoPixel RGB LEDs using a PIC microcontroller and C-language. A close-up of the NeoPixel (WS2812) LED is shown with attention to identifying various semiconductor elements inside the package. The principle operation of the LED is the described along with a detailed explanation of the pins and the one-wire communication protocol.
A simple evaluation board for the PIC18F4550 is used to drive a circular array of 60 NeoPixel LEDs from Adafruit. After presenting the difficulties of providing an accurate pulse-shape using the C-language, the measured waveform is shown on a Tektronix MDO4000B. Finally, the code for a circular color rotating pattern is presented and demoed. The code for the experiment can be downloaded here.
There is also equipment giveaway! A TPI Scope Plus 440 and a Tektronix TDS2232 are being given away at no charge! Please leave a comment on the video or on the website. You must be a resident of the USA to receive the giveaway. A winner will be chosen at a later date and notified via email.