Add serial-port controlled 6 DoF robot MEGATRON arm!

Author: Amadeus Stevenson

package.json

@@ -14,6 +14,7 @@
   "license": "ISC",
   "dependencies": {
     "johnny-five": "^0.8.8",
+    "serialport": "^1.4.6",
     "ws": "^0.4.32"
   }
 }

serial.js

@@ -0,0 +1,63 @@
+// TODO: set up 6 ranges for x1,x2,x3,
+// grab the leap data: leap reports x,z,y
+var webSocket = require('ws'),
+    ws = new webSocket('ws://127.0.0.1:6437'),
+    SerialPort = require("serialport").SerialPort,
+    leap_range = { x: [-150,120], y: [-20,100], z: [40,300] }, // mm
+    frame, palm,
+    serialPort = new SerialPort("/dev/tty.NoZAP-PL2303-00001014", {
+        baudrate: 115200
+    }),
+    servo_range = { x: [500,2500], y: [500,2500], z: [500,2500] };
+
+serialPort.on("open", function () {
+    ws.on('message', function(data, flags) {
+        frame = JSON.parse(data);
+        // if only one hand is present
+        //if (frame.hands && frame.hands.length == 1) {
+        if (frame.hands && frame.hands.length >= 2) {
+            // extract centre palm position in mm [x,y,z]
+            palm = {  left: frame.hands[0].palmPosition,
+                    right: frame.hands[1].palmPosition };
+
+            //console.log(palm[0],palm[1],palm[2]);
+            //console.log(map(palm[0],'x'),map(palm[2],'y'),map(palm[1],'z'));
+
+            serialPort.write("#0 P" + map(palm.left[0],'x') + " #1 P" + map(palm.left[2],'y') + " #2 P" + map(palm.left[1],'z') + " #3 P" + map(palm.right[1],'z') + " #4 P" + map(palm.right[1],'z') + " #5 P" + map(palm.right[1],'z') + " T1000\r\n");
+        } else {
+            console.log(frame.hands.length);
+        }
+    });
+});
+
+// map leap input to servo range
+function map(input,axis) {
+    switch (axis) {
+        case 'x':
+            servo=servo_range.x;
+            leap=leap_range.x;
+            break;
+        case 'y':
+            servo=servo_range.y;
+            leap=leap_range.y;
+            break;
+        case 'z':
+            servo=servo_range.z;
+            leap=leap_range.z;
+    }
+
+    var pos = Math.round(  // round to integer
+        servo[0] + ( (servo[1]-servo[0]) / (leap[1]-leap[0]) )
+            * (input - leap[0])
+    );
+
+    // bounds checking
+    pos = pos > servo[1] ? servo[1] : pos;
+    pos = pos < servo[0] ? servo[0] : pos;
+
+    return pos;
+}
+
+function sleep(millis) {
+    setTimeout(function() {}, millis);
+}