dgbuilder/core_nodes/hardware/36-rpi-gpio.js

   1 /**
   2  * Copyright 2013 IBM Corp.
   3  *
   4  * Licensed under the Apache License, Version 2.0 (the "License");
   5  * you may not use this file except in compliance with the License.
   6  * You may obtain a copy of the License at
   7  *
   8  * http://www.apache.org/licenses/LICENSE-2.0
   9  *
  10  * Unless required by applicable law or agreed to in writing, software
  11  * distributed under the License is distributed on an "AS IS" BASIS,
  12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  * See the License for the specific language governing permissions and
  14  * limitations under the License.
  15  **/
  16
  17 module.exports = function(RED) {
  18     "use strict";
  19     var util = require("util");
  20     var exec = require('child_process').exec;
  21     var fs =  require('fs');
  22
  23     var gpioCommand = '/usr/local/bin/gpio';
  24
  25     if (!fs.existsSync("/dev/ttyAMA0")) { // unlikely if not on a Pi
  26         throw "Info : Ignoring Raspberry Pi specific node.";
  27     }
  28
  29     if (!fs.existsSync(gpioCommand)) { // gpio command not installed
  30         throw "Info : Can't find Raspberry Pi wiringPi gpio command.";
  31     }
  32
  33     // Map physical P1 pins to Gordon's Wiring-Pi Pins (as they should be V1/V2 tolerant)
  34     var pintable = {
  35     // Physical : WiringPi
  36             "11":"0",
  37             "12":"1",
  38             "13":"2",
  39             "15":"3",
  40             "16":"4",
  41             "18":"5",
  42             "22":"6",
  43              "7":"7",
  44              "3":"8",
  45              "5":"9",
  46             "24":"10",
  47             "26":"11",
  48             "19":"12",
  49             "21":"13",
  50             "23":"14",
  51              "8":"15",
  52             "10":"16",
  53             "27":"30",
  54             "28":"31",
  55             "29":"21",
  56             "31":"22",
  57             "32":"26",
  58             "33":"23",
  59             "35":"24",
  60             "36":"27",
  61             "37":"25",
  62             "38":"28",
  63             "40":"29"
  64     }
  65     var tablepin = {
  66     // WiringPi : Physical
  67             "0":"11",
  68             "1":"12",
  69             "2":"13",
  70             "3":"15",
  71             "4":"16",
  72             "5":"18",
  73             "6":"22",
  74             "7":"7",
  75             "8":"3",
  76             "9":"5",
  77            "10":"24",
  78            "11":"26",
  79            "12":"19",
  80            "13":"21",
  81            "14":"23",
  82            "15":"8",
  83            "16":"10",
  84            "30":"27",
  85            "31":"28",
  86            "21":"29",
  87            "22":"31",
  88            "26":"32",
  89            "23":"33",
  90            "24":"35",
  91            "27":"36",
  92            "25":"37",
  93            "28":"38",
  94            "29":"40"
  95     }
  96
  97     function GPIOInNode(n) {
  98         RED.nodes.createNode(this,n);
  99         this.buttonState = -1;
 100         this.pin = pintable[n.pin];
 101         this.intype = n.intype;
 102         var node = this;
 103
 104         if (node.pin !== undefined) {
 105             exec(gpioCommand+" mode "+node.pin+" "+node.intype, function(err,stdout,stderr) {
 106                 if (err) { node.error(err); }
 107                 else {
 108                     node._interval = setInterval( function() {
 109                         exec(gpioCommand+" read "+node.pin, function(err,stdout,stderr) {
 110                             if (err) { node.error(err); }
 111                             else {
 112                                 if (node.buttonState !== Number(stdout)) {
 113                                     var previousState = node.buttonState;
 114                                     node.buttonState = Number(stdout);
 115                                     if (previousState !== -1) {
 116                                         var msg = {topic:"pi/"+tablepin[node.pin], payload:node.buttonState};
 117                                         node.send(msg);
 118                                     }
 119                                 }
 120                             }
 121                         });
 122                     }, 250);
 123                 }
 124             });
 125         }
 126         else {
 127             node.error("Invalid GPIO pin: "+node.pin);
 128         }
 129
 130         node.on("close", function() {
 131             clearInterval(node._interval);
 132         });
 133     }
 134
 135     function GPIOOutNode(n) {
 136         RED.nodes.createNode(this,n);
 137         this.pin = pintable[n.pin];
 138         var node = this;
 139
 140         if (node.pin !== undefined) {
 141             process.nextTick(function() {
 142                 exec(gpioCommand+" mode "+node.pin+" out", function(err,stdout,stderr) {
 143                     if (err) { node.error(err); }
 144                     else {
 145                         node.on("input", function(msg) {
 146                             if (msg.payload === "true") { msg.payload = true; }
 147                             if (msg.payload === "false") { msg.payload = false; }
 148                             var out = Number(msg.payload);
 149                             if ((out === 0)|(out === 1)) {
 150                                 exec(gpioCommand+" write "+node.pin+" "+out, function(err,stdout,stderr) {
 151                                     if (err) { node.error(err); }
 152                                 });
 153                             }
 154                             else { node.warn("Invalid input - not 0 or 1"); }
 155                         });
 156                     }
 157                 });
 158             });
 159         }
 160         else {
 161             node.error("Invalid GPIO pin: "+node.pin);
 162         }
 163
 164         node.on("close", function() {
 165             exec(gpioCommand+" mode "+node.pin+" in");
 166         });
 167     }
 168
 169     var pitype = { type:"" };
 170     exec(gpioCommand+" -v | grep Type", function(err,stdout,stderr) {
 171         if (err) {
 172             util.log('[36-rpi-gpio.js] Error: "'+gpioCommand+' -v" command failed for some reason.');
 173         }
 174         else {
 175             pitype = { type:(stdout.split(","))[0].split(": ")[1], rev:(stdout.split(","))[1].split(": ")[1] };
 176         }
 177     });
 178
 179     RED.nodes.registerType("rpi-gpio in",GPIOInNode);
 180     RED.nodes.registerType("rpi-gpio out",GPIOOutNode);
 181
 182     RED.httpAdmin.get('/rpi-gpio/:id',function(req,res) {
 183         res.send( JSON.stringify(pitype) );
 184     });
 185 }