title: Blog post: DisplayBacklight description: Mac OS X Arduino ambilight clone date: 2017-05-13 comments: true flattr: true github: https://github.com/xythobuz/DisplayBacklight parent: projects position: 100 --- DisplayBacklight is an Ambilight-clone made with an Arduino controlled by a macOS machine.
DisplayBacklight - macOS Arduino Ambilight Photo 1 Photo 2
### Hardware The software currently only supports driving RGB-LEDs with the colors from the edge of a screen, so you have to place an RGB LED strip on the outer edges of your computer monitors. Multiple screens are supported using a single LED strip for all of them. You need an LED strip with individually addressable LEDs like the popular [WS2812 RGB LED strips](https://www.sparkfun.com/products/12025). The data line is connected to pin 2 of the Arduino. The [Adafruit Neo-Pixel library](https://github.com/adafruit/Adafruit_NeoPixel) is used to control the LEDs. ### Protocol The color data is transmitted using the serial port and the USB-UART converter built into most Arduinos. Communication happens at 115200bps, the LED count is hardcoded in both firmware and host software. First, a magic string, also hardcoded, is sent, followed by 3 bytes containing Red, Green and Blue, for each LED. When the last byte has been received the whole strip is refreshed at once. ### Software The macOS host software is opening the connection to the serial port, grabbing a screenshot, processing the edges to calculate each LED color and finally sending it to the device.
Screenshot
### License DisplayBacklight itself is made by Thomas Buck and released under a BSD 2-Clause License. See the accompanying COPYING file.