Saturday, July 5, 2014

duino, control Arduino with Node.js

duino is a framework for working with Arduinos in node.js. Here show how to (with little bit modification) make it run on Ubuntu, to control the LED of Arduino Due using Node.js.

- Connect Arduino Due to your host PC with USB cable.

- In Arduino Due board -

Create a new sketch, copy the source code of du.ino here, https://github.com/ecto/duino/blob/master/src/du.ino.


You will be complained with error of 'int index' redeclared as different kind of symbol. To fix it, rename variable index, for example idx.

#include <Servo.h>


bool debug = false;

int idx = 0;

char messageBuffer[12];
char cmd[3];
char pin[3];
char val[4];
char aux[4];

Servo servo;

void setup() {
  Serial.begin(115200);
}

void loop() {
  while(Serial.available() > 0) {
    char x = Serial.read();
    if (x == '!') idx = 0;      // start
    else if (x == '.') process(); // end
    else messageBuffer[idx++] = x;
  }
}

/*
 * Deal with a full message and determine function to call
 */
void process() {
  idx = 0;

  strncpy(cmd, messageBuffer, 2);
  cmd[2] = '\0';
  strncpy(pin, messageBuffer + 2, 2);
  pin[2] = '\0';

  if (atoi(cmd) > 90) {
    strncpy(val, messageBuffer + 4, 2);
    val[2] = '\0';
    strncpy(aux, messageBuffer + 6, 3);
    aux[3] = '\0';
  } else {
    strncpy(val, messageBuffer + 4, 3);
    val[3] = '\0';
    strncpy(aux, messageBuffer + 7, 3);
    aux[3] = '\0';
  }

  if (debug) {
    Serial.println(messageBuffer);
  }
  int cmdid = atoi(cmd);

  // Serial.println(cmd);
  // Serial.println(pin);
  // Serial.println(val);
  // Serial.println(aux);

  switch(cmdid) {
    case 0:  sm(pin,val);              break;
    case 1:  dw(pin,val);              break;
    case 2:  dr(pin,val);              break;
    case 3:  aw(pin,val);              break;
    case 4:  ar(pin,val);              break;
    case 97: handlePing(pin,val,aux);  break;
    case 98: handleServo(pin,val,aux); break;
    case 99: toggleDebug(val);         break;
    default:                           break;
  }
}

/*
 * Toggle debug mode
 */
void toggleDebug(char *val) {
  if (atoi(val) == 0) {
    debug = false;
    Serial.println("goodbye");
  } else {
    debug = true;
    Serial.println("hello");
  }
}

/*
 * Set pin mode
 */
void sm(char *pin, char *val) {
  if (debug) Serial.println("sm");
  int p = getPin(pin);
  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  if (atoi(val) == 0) {
    pinMode(p, OUTPUT);
  } else {
    pinMode(p, INPUT);
  }
}

/*
 * Digital write
 */
void dw(char *pin, char *val) {
  if (debug) Serial.println("dw");
  int p = getPin(pin);
  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  pinMode(p, OUTPUT);
  if (atoi(val) == 0) {
    digitalWrite(p, LOW);
  } else {
    digitalWrite(p, HIGH);
  }
}

/*
 * Digital read
 */
void dr(char *pin, char *val) {
  if (debug) Serial.println("dr");
  int p = getPin(pin);
  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  pinMode(p, INPUT);
  int oraw = digitalRead(p);
  char m[7];
  sprintf(m, "%02d::%02d", p,oraw);
  Serial.println(m);
}

/*
 * Analog read
 */
void ar(char *pin, char *val) {
  if(debug) Serial.println("ar");
  int p = getPin(pin);
  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  pinMode(p, INPUT); // don't want to sw
  int rval = analogRead(p);
  char m[8];
  sprintf(m, "%s::%03d", pin, rval);
  Serial.println(m);
}

void aw(char *pin, char *val) {
  if(debug) Serial.println("aw");
  int p = getPin(pin);
  pinMode(p, OUTPUT);
  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  analogWrite(p,atoi(val));
}

int getPin(char *pin) { //Converts to A0-A5, and returns -1 on error
  int ret = -1;
  if(pin[0] == 'A' || pin[0] == 'a') {
    switch(pin[1]) {
      case '0':  ret = A0; break;
      case '1':  ret = A1; break;
      case '2':  ret = A2; break;
      case '3':  ret = A3; break;
      case '4':  ret = A4; break;
      case '5':  ret = A5; break;
      default:             break;
    }
  } else {
    ret = atoi(pin);
    if(ret == 0 && (pin[0] != '0' || pin[1] != '0')) {
      ret = -1;
    }
  }
  return ret;
}

/*
 * Handle Ping commands
 * fire, read
 */
void handlePing(char *pin, char *val, char *aux) {
  if (debug) Serial.println("ss");
  int p = getPin(pin);

  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  Serial.println("got signal");

  // 01(1) Fire and Read
  if (atoi(val) == 1) {
    char m[16];

    pinMode(p, OUTPUT);
    digitalWrite(p, LOW);
    delayMicroseconds(2);
    digitalWrite(p, HIGH);
    delayMicroseconds(5);
    digitalWrite(p, LOW);

    Serial.println("ping fired");

    pinMode(p, INPUT);
    sprintf(m, "%s::read::%08d", pin, pulseIn(p, HIGH));
    Serial.println(m);

    delay(50);
  }
}

/*
 * Handle Servo commands
 * attach, detach, write, read, writeMicroseconds, attached
 */
void handleServo(char *pin, char *val, char *aux) {
  if (debug) Serial.println("ss");
  int p = getPin(pin);
  if(p == -1) { if(debug) Serial.println("badpin"); return; }
  Serial.println("signal: servo");

  // 00(0) Detach
  if (atoi(val) == 0) {
    servo.detach();
    char m[12];
    sprintf(m, "%s::detached", pin);
    Serial.println(m);

  // 01(1) Attach
  } else if (atoi(val) == 1) {
    // servo.attach(p, 750, 2250);
    servo.attach(p);
    char m[12];
    sprintf(m, "%s::attached", pin);
    Serial.println(m);

  // 02(2) Write
  } else if (atoi(val) == 2) {
    Serial.println("writing to servo");
    Serial.println(atoi(aux));
    // Write to servo
    servo.write(atoi(aux));
    delay(15);

    // TODO: Experiment with microsecond pulses
    // digitalWrite(pin, HIGH);   // start the pulse
    // delayMicroseconds(pulseWidth);  // pulse width
    // digitalWrite(pin, LOW);    // stop the pulse

  // 03(3) Read
  } else if (atoi(val) == 3) {
    Serial.println("reading servo");
    int sval = servo.read();
    char m[13];
    sprintf(m, "%s::read::%03d", pin, sval);
    Serial.println(m);
  }
}

Compile and upload to Arduino Due board.

- In Host PC, running Ubuntu -

Install duino for Node.js, run the command:

$ npm install duino

Create a .js file, testDuino.js. Copy the example code here, https://github.com/ecto/duino#usage.



You will be complained with error of Cannot open /dev/vboxusb.

To make it run on Ubuntu with usb port of ACMxx, modify  arduino.Board to have device: "ACM".

var arduino = require('duino');
var board = new arduino.Board({
  device: "ACM"
});

var led = new arduino.Led({
  board: board,
  pin: 13
});

led.blink();

- Now you can run your node.js code to toggle the LED on Arduino board.

$ node testDuino


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