/** * Copyright 2014 Maxwell R Hadley * * 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. **/ // Require main module var RED = require(process.env.NODE_RED_HOME + "/red/red"); // Require bonescript try { var bonescript = require("bonescript"); } catch (err) { require("util").log("[145-digital-in] Error: cannot find module 'bonescript'"); } // The node constructor function DiscreteInputNode(n) { RED.nodes.createNode(this, n); // Store local copies of the node configuration (as defined in the .html) this.topic = n.topic; // the topic is not currently used this.pin = n.pin; // The Beaglebone Black pin identifying string if (n.activeLow) // Set the 'active' state 0 or 1 as appropriate this.activeState = 0; else this.activeState = 1; this.updateInterval = n.updateInterval * 1000; // How often to send totalActiveTime messages this.interruptAttached = false; // Flag: should we detach interrupt when we are closed? this.intervalId = null; // Remember the timer ID so we can delete it when we are closed this.currentState = 0; // The pin input state "1" or "0" this.lastActiveTime = NaN; // The date (in ms since epoch) when the pin last went high this.totalActiveTime = 0; // The total time in ms that the pin has been high (since reset) this.starting = true; // Define 'node' to allow us to access 'this' from within callbacks (the 'var' is essential - // otherwise there is only one global 'node' for all instances of DiscreteInputNode!) var node = this; // This function is called whenever the input pin changes state. We update the currentState // and the ActiveTime variables, and send a message on the first output with the new state // Note: this function gets called spuriously when the interrupt is first enabled: in this // case x.value is undefined - we must test for this var interruptCallback = function (x) { // node.log("interruptCallback: x.value = " + x.value); // node.log("interruptCallback: node.currentState = " + node.currentState); // node.log("interruptCallback: node.totalActiveTime = " + node.totalActiveTime); // node.log("interruptCallback: node.lastActiveTime = " + node.lastActiveTime); if (node.currentState === x.value - 0) { node.log("Spurious interrupt: " + x.value); } else if (x.value != undefined) { node.currentState = x.value - 0; var now = Date.now(); if (node.currentState === node.activeState) { node.lastActiveTime = now; } else if (!isNaN(node.lastActiveTime)) { node.totalActiveTime += now - node.lastActiveTime; } var msg = {}; msg.topic = node.topic; msg.payload = node.currentState; node.send([msg, null]); } }; // This function is called by the timer. It updates the ActiveTime variables, and sends a // message on the second output with the latest value of the total active time, in seconds var timerCallback = function () { // node.log("timerCallback: node.currentState = " + node.currentState); // node.log("timerCallback: node.totalActiveTime = " + node.totalActiveTime); // node.log("timerCallback: node.lastActiveTime = " + node.lastActiveTime); if (node.currentState === node.activeState) { var now = Date.now(); node.totalActiveTime += now - node.lastActiveTime; node.lastActiveTime = now; } var msg = {}; msg.topic = node.topic; msg.payload = node.totalActiveTime / 1000; node.send([null, msg]); }; // This function is called when we receive an input message. Clear the ActiveTime variables // (so we start counting from zero again) var inputCallback = function (msg) { // node.log("inputCallback: node.currentState = " + node.currentState); // node.log("inputCallback: node.totalActiveTime = " + node.totalActiveTime); // node.log("inputCallback: node.lastActiveTime = " + node.lastActiveTime); node.totalActiveTime = 0; if (node.currentState === node.activeState) { node.lastActiveTime = Date.now(); } if (node.starting) { node.starting = false; var msg = [{topic:node.topic}, {topic:node.topic}]; msg[0].payload = node.currentState; msg[1].payload = node.totalActiveTime; node.send(msg); // node.log("Initial message: " + msg[0].payload + " " + msg[1].payload); // node.log("currentState: " + node.currentState); // node.log("activeTime: " + node.totalActiveTime); } }; // If we have a valid pin, set it as an input and read the (digital) state if (["P8_7", "P8_8", "P8_9", "P8_10", "P8_11", "P8_12", "P8_13", "P8_14", "P8_15", "P8_16", "P8_17", "P8_18", "P8_19", "P8_26", "P9_11", "P9_12", "P9_13", "P9_14", "P9_15", "P9_16", "P9_17", "P9_18", "P9_21", "P9_22", "P9_23", "P9_24", "P9_26", "P9_27", "P9_30", "P9_41", "P9_42"].indexOf(node.pin) >= 0) { setTimeout(function () { bonescript.pinMode(node.pin, bonescript.INPUT); bonescript.digitalRead(node.pin, function (x) { // Initialise the currentState and lastActveTime variables based on the value read // node.log("digitalRead: x.value = " + x.value); // node.log("digitalRead: node.currentState = " + node.currentState); // node.log("digitalRead: node.totalActiveTime = " + node.totalActiveTime); // node.log("digitalRead: node.lastActiveTime = " + node.lastActiveTime); node.currentState = x.value - 0; // node.log("First read - currentState: " + node.currentState); if (node.currentState === node.activeState) { node.lastActiveTime = Date.now(); } // Attempt to attach a change-of-state interrupt handler to the pin. If we succeed, // set the input event and interval handlers, then send an initial message with the // pin state on the first output if (bonescript.attachInterrupt(node.pin, true, bonescript.CHANGE, interruptCallback)) { node.interruptAttached = true; node.on("input", inputCallback); node.intervalId = setInterval(timerCallback, node.updateInterval); } else { node.error("Failed to attach interrupt"); } setTimeout(function () { node.emit("input", {}); }, 50); }); }, 50); } else { node.error("Unconfigured input pin"); } } // Register the node by name. This must be called before overriding any of the Node functions. RED.nodes.registerType("discrete-in", DiscreteInputNode); // On close, detach the interrupt (if we attached one) and clear the interval (if we set one) DiscreteInputNode.prototype.close = function () { if (this.interruptAttached) { bonescript.detachInterrupt(this.pin); } if (this.intervalId !== null) { clearInterval(this.intervalId); } };