Jassif Team Institution

pi@jassifteam:~ $ sudo shutdown -h now

LED1 to rows 5 (cathode) & 6 (anode) column J
LED2 to rows 8 (cathode) & 9 (anode) column J
LED3 to rows 11 (cathode) & 12 (anode) column J
LED4 to rows 14 (cathode) & 15 (anode) column J
LED5 to rows 17 (cathode) & 18 (anode) column J
LED6 to rows 20 (cathode) & 21 (anode) column J
LED7 to rows 23 (cathode) & 24 (anode) column J
LED8 to rows 26 (cathode) & 27 (anode) column J

LED1 to row 5 column I
LED2 to row 8 column I
LED3 to row 11 column I
LED4 to row 14 column I
LED5 to row 17 column I
LED6 to row 20 column I
LED7 to row 23 column I
LED8 to row 26 column I

LED1 from Physical Pin 7 (GPIO 4, row 4, left column) to Tie-point row 6 column F
LED2 from Physical Pin 11 (GPIO 17, row 6, left column) to Tie-point row 9 column F
LED3 from Physical Pin 13 (GPIO 27, row 7, left column) to Tie-point row 12 column F
LED4 from Physical Pin 15 (GPIO 22, row 8, left column) to Tie-point row 15 column F
LED5 from Physical Pin 12 (GPIO 18, row 6, right column) to Tie-point row 18 column F
LED6 from Physical Pin 16 (GPIO 23, row 8, right column) to Tie-point row 21 column F
LED7 from Physical Pin 18 (GPIO 24, row 9, right column) to Tie-point row 24 column F
LED8 from Physical Pin 22 (GPIO 25, row 11, right column) to Tie-point row 27 column F

pi@jassifteam:~ $ nano flowingleds.js

flowingleds.js

let Gpio = require('onoff').Gpio; //include onoff to interact with the GPIO
let LED04 = new Gpio(4, 'out'), //use declare variables for all the GPIO output pins
  LED17 = new Gpio(17, 'out'),
  LED27 = new Gpio(27, 'out'),
  LED22 = new Gpio(22, 'out'),
  LED18 = new Gpio(18, 'out'),
  LED23 = new Gpio(23, 'out'),
  LED24 = new Gpio(24, 'out'),
  LED25 = new Gpio(25, 'out');

//Put all the LED variables in an array
let leds = [LED04, LED17, LED27, LED22, LED18, LED23, LED24, LED25];
let indexCount = 0; //a counter
dir = "up"; //variable for flowing direction

let flowInterval = setInterval(flowingLeds, 100); //run the flowingLeds function every 100ms

function flowingLeds() { //function for flowing Leds
  leds.forEach(function(currentValue) { //for each item in array
    currentValue.writeSync(0); //turn off LED
  });
  if (indexCount == 0) dir = "up"; //set flow direction to "up" if the count reaches zero
  if (indexCount >= leds.length) dir = "down"; //set flow direction to "down" if the count reaches 7
  if (dir == "down") indexCount--; //count downwards if direction is down
  leds[indexCount].writeSync(1); //turn on LED that where array index matches count
  if (dir == "up") indexCount++ //count upwards if direction is up
};

function unexportOnClose() { //function to run when exiting program
  clearInterval(flowInterval); //stop flow interwal
  leds.forEach(function(currentValue) { //for each LED
    currentValue.writeSync(0); //turn off LED
    currentValue.unexport(); //unexport GPIO
  });
};

process.on('SIGINT', unexportOnClose); //function to run when user closes using ctrl+cc

pi@jassifteam:~ $ node flowingleds.js