Node.js `pigpio` + two servos

README.md

Node.js (pigpio) + two servos

Requirements

• sudo npm install -g pigpio

Use

cd ~ && \
git clone https://gist.github.com/poulou0/a20c61d41f6f5b787caab4bd10cdf13b pigpio-servos && \
cd pigpio-servos && \
sudo node servos.js

servos.js

#!/usr/bin/env node
process.env.NODE_PATH = "/usr/lib/node_modules";
require("module").Module._initPaths();

const Gpio = require('pigpio').Gpio;
const stdin = process.stdin;
stdin.setRawMode( true );
stdin.resume();
stdin.setEncoding( 'utf8' );

const motorX = new Gpio(14, {mode: Gpio.OUTPUT});
const motorY = new Gpio(15, {mode: Gpio.OUTPUT});
let motorXpulseMax = 1750,
    motorYpulseMax = 2500,
    motorXpulseMin = 500,
    motorYpulseMin = 500,
    motorXpulseCurrent = 1125,
    motorYpulseCurrent = 1500,
    motorXpulseTarget = 1125,
    motorYpulseTarget = 1500,
    step = 150
    smoothMovement = true;

setInterval(() => {
  if (!smoothMovement) motorXpulseCurrent = motorXpulseTarget
  else if (motorXpulseCurrent < motorXpulseTarget) motorXpulseCurrent += 1;
  else if (motorXpulseCurrent > motorXpulseTarget) motorXpulseCurrent -= 1;
  if (motorXpulseCurrent > motorXpulseMax) motorXpulseCurrent = motorXpulseMax;
  else if (motorXpulseCurrent < motorXpulseMin) motorXpulseCurrent = motorXpulseMin;
  motorX.servoWrite(motorXpulseCurrent);

  if (!smoothMovement) motorYpulseCurrent = motorYpulseTarget;
  else if(motorYpulseCurrent < motorYpulseTarget) motorYpulseCurrent += 1;
  else if (motorYpulseCurrent > motorYpulseTarget) motorYpulseCurrent -= 1;
  if (motorYpulseCurrent > motorYpulseMax) motorYpulseCurrent = motorYpulseMax;
  else if (motorYpulseCurrent < motorYpulseMin) motorYpulseCurrent = motorYpulseMin;
  motorY.servoWrite(motorYpulseCurrent);
}, 4);

(async () => {
  motorX.servoWrite(motorXpulseCurrent);
  motorY.servoWrite(motorYpulseCurrent);

  stdin.on( 'data', function( key ) {
    if ( key === '\u0003' ) { // ctrl-c ( end of text )
      process.exit();
    } else if ( key === '\033[D' ) { //left, Y+
      motorYpulseTarget = motorYpulseCurrent + step;
    } else if ( key === '\033[C' ) { //right, Y-
      motorYpulseTarget = motorYpulseCurrent - step;
    } else if ( key === '\033[A' ) { //up, X+
      motorXpulseTarget = motorXpulseCurrent + step;
    } else if ( key === '\033[B' ) { //down, X-
      motorXpulseTarget = motorXpulseCurrent - step;
    } else if ( key === '\u0020' ) { //space
      smoothMovement = !smoothMovement;
    }
    // write the key to stdout all normal like
    // process.stdout.write( key );
  });
})();