Chromebook Pixel Lightbar: Rainbow Flow

README.md

A gorgeous looping gradient for the Chromebook Pixel lightbar.

To use on your Dev Mode-enabled machine, copy this script, open a Chrome OS shell (Ctrl+Alt+T) and type shell. Right click to paste the code and press Enter; it'll start running after a second.

rainbow.sh

(
separateLightsBy=12
speed=0.08
 
declare -a Gradient=('0 BF BF' '0 C3 BC' '0 C6 B8' '1 CA B4' '1 CD B0' '2 D0 AC' '2 D4 A8' '3 D7 A5' '4 DA A0' '5 DD 9C' '7 DF 98' '8 E2 94' 'A E5 90' 'B E7 8C' 'D EA 88' 'F EC 84' '11 EE 80' '13 F0 7B' '15 F2 77' '18 F4 73' '1A F5 6F' '1D F7 6B' '20 F8 67' '22 FA 63' '25 FB 5F' '28 FC 5A' '2B FD 57' '2F FD 53' '32 FE 4F' '35 FE 4B' '39 FF 47' '3C FF 43' '40 FF 40' '43 FF 3C' '47 FF 39' '4B FE 35' '4F FE 32' '53 FD 2F' '57 FD 2B' '5A FC 28' '5F FB 25' '63 FA 22' '67 F8 20' '6B F7 1D' '6F F5 1A' '73 F4 18' '77 F2 15' '7B F0 13' '7F EE 11' '84 EC F' '88 EA D' '8C E7 B' '90 E5 A' '94 E2 8' '98 DF 7' '9C DD 5' 'A0 DA 4' 'A5 D7 3' 'A8 D4 2' 'AC D0 2' 'B0 CD 1' 'B4 CA 1' 'B8 C6 0' 'BC C3 0' 'BF BF 0' 'C3 BC 0' 'C6 B8 0' 'CA B4 1' 'CD B0 1' 'D0 AC 2' 'D4 A8 2' 'D7 A5 3' 'DA A0 4' 'DD 9C 5' 'DF 98 7' 'E2 94 8' 'E5 90 A' 'E7 8C B' 'EA 88 D' 'EC 84 F' 'EE 80 11' 'F0 7B 13' 'F2 77 15' 'F4 73 18' 'F5 6F 1A' 'F7 6B 1D' 'F8 67 20' 'FA 63 22' 'FB 5F 25' 'FC 5A 28' 'FD 57 2B' 'FD 53 2F' 'FE 4F 32' 'FE 4B 35' 'FF 47 39' 'FF 43 3C' 'FF 40 40' 'FF 3C 43' 'FF 39 47' 'FE 35 4B' 'FE 32 4F' 'FD 2F 53' 'FD 2B 57' 'FC 28 5A' 'FB 25 5F' 'FA 22 63' 'F8 20 67' 'F7 1D 6B' 'F5 1A 6F' 'F4 18 73' 'F2 15 77' 'F0 13 7B' 'EE 11 7F' 'EC F 84' 'EA D 88' 'E7 B 8C' 'E5 A 90' 'E2 8 94' 'DF 7 98' 'DD 5 9C' 'DA 4 A0' 'D7 3 A5' 'D4 2 A8' 'D0 2 AC' 'CD 1 B0' 'CA 1 B4' 'C6 0 B8' 'C3 0 BC' 'BF 0 BF' 'BC 0 C3' 'B8 0 C6' 'B4 1 CA' 'B0 1 CD' 'AC 2 D0' 'A8 2 D4' 'A5 3 D7' 'A0 4 DA' '9C 5 DD' '98 7 DF' '94 8 E2' '90 A E5' '8C B E7' '88 D EA' '84 F EC' '80 11 EE' '7B 13 F0' '77 15 F2' '73 18 F4' '6F 1A F5' '6B 1D F7' '67 20 F8' '63 22 FA' '5F 25 FB' '5A 28 FC' '57 2B FD' '53 2F FD' '4F 32 FE' '4B 35 FE' '47 39 FF' '43 3C FF' '40 40 FF' '3C 43 FF' '39 47 FF' '35 4B FE' '32 4F FE' '2F 53 FD' '2B 57 FD' '28 5A FC' '25 5F FB' '22 63 FA' '20 67 F8' '1D 6B F7' '1A 6F F5' '18 73 F4' '15 77 F2' '13 7B F0' '11 7F EE' 'F 84 EC' 'D 88 EA' 'B 8C E7' 'A 90 E5' '8 94 E2' '7 98 DF' '5 9C DD' '4 A0 DA' '3 A5 D7' '2 A8 D4' '2 AC D0' '1 B0 CD' '1 B4 CA' '0 B8 C6' '0 BC C3' )
trap ctrl_c INT
ctrl_c() {
  breakSignal=1
}
breakSignal=0;i=0;
 
sudo ectool lightbar seq stop &>/dev/null
sudo ectool lightbar 4 00 00 00 &>/dev/null

sleep 1
printf "\n\nEnjoy the rainbow! To return to normal, hit Ctrl+C.\n\n"
while :
do
  if [ $breakSignal -eq 1 ]; then
    break
  fi
  sudo ectool lightbar 0 ${Gradient[$((($i+$separateLightsBy*3)%192))]} &>/dev/null
  sudo ectool lightbar 1 ${Gradient[$((($i+$separateLightsBy*2)%192))]} &>/dev/null
  sudo ectool lightbar 2 ${Gradient[$((($i+$separateLightsBy*1)%192))]} &>/dev/null
  sudo ectool lightbar 3 ${Gradient[$((($i)%192))]} &>/dev/null
  i=$(($i+1));
  if [ $i -gt 191 ]; then
    i=0;
  fi
  sleep $speed
done
 
sudo ectool lightbar 4 00 00 00 &>/dev/null
sleep 1
sudo ectool lightbar seq run &>/dev/null
)

Great stuff, thanks for sharing. I'm new to Chrome OS and programming, what language is this?