How to export an initialized board with sensors as a module

Question

As a basic example, I have:

//tempModule.js
var five = require("johnny-five");
var board = new five.Board();
var temp;
board.on("ready", function() {
   temp = new five.Temperature({
pin: "A2",
controller: "AD8495"
   });
});
module.export = board;

Which gets called by: //moduleTest.js

var board = require('tempModule.js');

setInterval(function(){
     console.log("Temp: " + board.temp);
  },500);

This code is currently returning "undefined". How do I structure tempModule.js so that the data from the sensors attached to the board can be utilized in another program?

Molda · Accepted Answer · 2016-03-19T10:49:36.503

1.the temp variable is not property of board so board.temp doesn't make sense.

2.You're not exporting temp so you can't access it.

So you need to export temp like

module.exports = temp;

or use

exports.board = board; 
exports.temp = temp;

then

var module = require('tempModule.js');

and access it using

var board = module.board;
var temp = module.temp;

If the above still doesn't work then there's another way

tempModule.js

var five = require("johnny-five"); 
var board = new five.Board();

function init(cb){
    board.on("ready", function() {
        var temp = new five.Temperature({ pin: "A2", controller: "AD8495" }); 
        cb(temp);
    });
}
exports.init = init;

and use it like this

var tempModule = require('tempModule.js');

tempModule.init(function (temp){
    temp.on("data", function() { 
        console.log(this.celsius + "°C", this.fahrenheit + "°F"); 
    });
});

Update: Added another example

// boardModule.js
var five = require("johnny-five"); 
var b = new five.Board();
var board = {};

function init(cb){
    b.on("ready", function() {
        board.temp1 = new five.Temperature({ pin: "A2", controller: "AD8495" }); 
        board.temp2 = new five.Temperature({ pin: "A3", controller: "AD8495" });
        board.temp3 = new five.Temperature({ pin: "A4", controller: "AD8495" }); 
        board.motor1 = new five.Motor({ pin: 5 });

        cb(board);
    });
}
exports.init = init;

// testModule.js
var boardModule = require('boardModule.js');

boardModule.init(function (board){

    board.temp1.on("data", function() { 
        console.log('temp1:', this.celsius + "°C", this.fahrenheit + "°F"); 
    });

    board.temp2.on("data", function() { 
        console.log('temp2:', this.celsius + "°C", this.fahrenheit + "°F"); 
    });

    board.temp3.on("data", function() { 
        console.log('temp3:', this.celsius + "°C", this.fahrenheit + "°F"); 
    });


    board.motor1.on("start", function() {
        console.log("start", Date.now());

        // Demonstrate motor stop in 2 seconds
        board.wait(2000, function() {
            board.motor1.stop();
        });
    });

    board.motor1.on("stop", function() {
        console.log("stop", Date.now());
    });

    board.motor1.start();
});

Thank you for the response. The second method works well, unfortunately its unsuitable in the context of what I need. I need to pass in an initialized board object with some 11 sensors/devices/motors/switches, etc attached to it, so that for example the temperature sensor can be accessed as board.temp, a motor as board.motor, etc. I have found that I can assign the temp object when it is declared as board.temp, then access it later within the total board.on("ready"... function, but outside of that it is undefined. Any idea how to get around this? So I only have to export the board object? — bstein5, Mar 18 '16 at 00:22
You shouldn't extend *board* variable, you could overwrite some board's properties. That's bad idea. Instead create your own object to hold all your sensors, motors, etc. If I have time I'll update my answer with an example later today when I get to my PC. — Molda, Mar 18 '16 at 07:18

How to export an initialized board with sensors as a module

1 Answers1