node-red/nodes/core/io/25-serial.js

/**
 * Copyright 2013 IBM Corp.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 **/

var RED = require(process.env.NODE_RED_HOME+"/red/red");
var settings = RED.settings;
var events = require("events");
var util = require("util");
var serialp = require("serialport");

// TODO: 'serialPool' should be encapsulated in SerialPortNode

function SerialPortNode(n) {
    RED.nodes.createNode(this,n);
    this.serialport = n.serialport;
    this.serialbaud = n.serialbaud * 1;
    this.newline = n.newline;
    this.addchar = n.addchar || "false";
}
RED.nodes.registerType("serial-port",SerialPortNode);


function SerialOutNode(n) {
    RED.nodes.createNode(this,n);
    this.serial = n.serial;
    this.serialConfig = RED.nodes.getNode(this.serial);

    if (this.serialConfig) {
        var node = this;
        node.port = serialPool.get(this.serialConfig.serialport,this.serialConfig.serialbaud,this.serialConfig.newline);
        node.addCh = "";
        if (node.serialConfig.addchar == "true") { node.addCh = this.serialConfig.newline.replace("\\n","\n").replace("\\r","\r"); }
        node.on("input",function(msg) {
            var payload = msg.payload;
            if (typeof payload === "object") { payload = JSON.stringify(payload); }
            if (typeof payload !== "buffer") { payload = new String(payload) + node.addCh; }
            node.port.write(payload,function(err,res) {
                if (err) {
                    node.error(err);
                }
            });
        });
    } else {
        this.error("missing serial config");
    }

    this.on("close", function() {
        if (this.serialConfig) {
            serialPool.close(this.serialConfig.serialport);
        }
    });
}
RED.nodes.registerType("serial out",SerialOutNode);


function SerialInNode(n) {
    RED.nodes.createNode(this,n);
    this.serial = n.serial;
    this.serialConfig = RED.nodes.getNode(this.serial);

    if (this.serialConfig) {
        var node = this;
        this.port = serialPool.get(this.serialConfig.serialport,this.serialConfig.serialbaud,this.serialConfig.newline);
        this.port.on('data', function(msg) {
            node.send({ "payload": msg });
        });
    } else {
        this.error("missing serial config");
    }

    this.on("close", function() {
        if (this.serialConfig) {
            try {
                serialPool.close(this.serialConfig.serialport);
            } catch(err) {
            }
            this.warn("Deploying with serial-port nodes is known to occasionally cause Node-RED to hang. This is due to an open issue with the underlying module.");
        }
    });
}
RED.nodes.registerType("serial in",SerialInNode);


var serialPool = function() {
    var connections = {};
    return {
        get:function(port,baud,newline,callback) {
            var id = port;
            if (!connections[id]) {
                connections[id] = function() {
                    var obj = {
                        _emitter: new events.EventEmitter(),
                        serial: null,
                        _closing: false,
                        tout: null,
                        on: function(a,b) { this._emitter.on(a,b); },
                        close: function(cb) { this.serial.close(cb); },
                        write: function(m,cb) { this.serial.write(m,cb); },
                    }
                    newline = newline.replace("\\n","\n").replace("\\r","\r");
                    var setupSerial = function() {
                        if (newline == "") {
                            obj.serial = new serialp.SerialPort(port,{
                                baudrate: baud,
                                parser: serialp.parsers.raw
                            },true, function(err, results) { if (err) obj.serial.emit('error',err); });
                        }
                        else {
                            obj.serial = new serialp.SerialPort(port,{
                                baudrate: baud,
                                parser: serialp.parsers.readline(newline)
                            },true, function(err, results) { if (err) obj.serial.emit('error',err); });
                        }
                        obj.serial.on('error', function(err) {
                            util.log("[serial] serial port "+port+" error "+err);
                            obj.tout = setTimeout(function() {
                                setupSerial();
                            }, settings.serialReconnectTime);
                        });
                        obj.serial.on('close', function() {
                            if (!obj._closing) {
                                util.log("[serial] serial port "+port+" closed unexpectedly");
                                obj.tout = setTimeout(function() {
                                    setupSerial();
                                }, settings.serialReconnectTime);
                            }
                        });
                        obj.serial.on('open',function() {
                            util.log("[serial] serial port "+port+" opened at "+baud+" baud");
                            if (obj.tout) { clearTimeout(obj.tout); }
                            obj.serial.flush();
                            obj._emitter.emit('ready');
                        });
                        obj.serial.on('data',function(d) {
                            if (typeof d !== "string") {
                                d = d.toString();
                                for (i=0; i<d.length; i++) {
                                    obj._emitter.emit('data',d.charAt(i));
                                }
                            }
                            else {
                                obj._emitter.emit('data',d);
                            }
                        });
                    }
                    setupSerial();
                    return obj;
                }();
            }
            return connections[id];
        },
        close: function(port) {
            if (connections[port]) {
                if (connections[port].tout != null) clearTimeout(connections[port].tout);
                connections[port]._closing = true;
                try {
                    connections[port].close(function() {
                        util.log("[serial] serial port closed");
                    });
                } catch(err) { };
            }
            delete connections[port];
        }
    }
}();

RED.app.get("/serialports",function(req,res) {
    serialp.list(function (err, ports) {
        res.writeHead(200, {'Content-Type': 'text/plain'});
        res.write(JSON.stringify(ports));
        res.end();
    });
});