From 83f7ff429f68e33bbfec768503f69651257cd315 Mon Sep 17 00:00:00 2001 From: Maxwell Hadley Date: Mon, 3 Feb 2014 20:08:33 +0000 Subject: [PATCH] Added BBB-digital-in Added digital input node - initially this is just BBB-discrete-in --- hardware/BBB/145-digital-in.html | 111 +++++++++++++++++++++++++ hardware/BBB/145-digital-in.js | 137 +++++++++++++++++++++++++++++++ 2 files changed, 248 insertions(+) create mode 100644 hardware/BBB/145-digital-in.html create mode 100644 hardware/BBB/145-digital-in.js diff --git a/hardware/BBB/145-digital-in.html b/hardware/BBB/145-digital-in.html new file mode 100644 index 00000000..dcca5583 --- /dev/null +++ b/hardware/BBB/145-digital-in.html @@ -0,0 +1,111 @@ + + + + + + + + + + + + + diff --git a/hardware/BBB/145-digital-in.js b/hardware/BBB/145-digital-in.js new file mode 100644 index 00000000..0b98d1d4 --- /dev/null +++ b/hardware/BBB/145-digital-in.js @@ -0,0 +1,137 @@ +/** + * 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 bs = require("bonescript"); +} catch(err) { + require("util").log("[BBB-discrete-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 + this.updateInterval = n.updateInterval*1000; // How often to send total active time messages + + // Define 'node' to allow us to access 'this' from within callbacks (the 'var' is essential - + // otherwise there is only one 'node' for all instances of DiscreteInputNode!) + var node = this; + 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 = 0; // 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; + + // This function is called whenver 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 + var interruptCallback = function (x) { + if (node.currentState == x.value) { + node.error("Spurious interrupt" + x.value); + } else { + node.currentState = x.value; + var now = Date.now(); + if (node.currentState == "1") { + node.lastActiveTime = now; + } else { + node.totalActiveTime += now - node.lastActiveTime; + } + } + var msg = {}; + 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 () { + if (node.currentState == "1") { + var now = Date.now(); + node.totalActiveTime += now - node.lastActiveTime; + node.lastActiveTime = now; + } + var msg = {}; + 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.totalActiveTime = 0; + if (node.currentState == "1") { + node.lastActiveTime = Date.now(); + } + if (node.starting) { + node.starting = 0; + var msg1 = {}; + msg1.payload = node.currentState; + var msg2 = {}; + msg2.payload = node.totalActiveTime/1000; + node.send([null, msg2]); + node.send([msg1, null]); + node.error("Initial message" + msg1 + " " + msg2); + } + }; + + // 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) { + bs.pinMode(node.pin, bs.INPUT); + bs.digitalRead(node.pin, function (x) { + // Initialise the currentState and lastActveTime variables based on the value read + node.currentState = x; + if (node.currentState == "1") { + 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 (bs.attachInterrupt(node.pin, true, bs.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.starting = 1; node.emit("input", {}); }, 250); + }); + } 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("BBB-discrete-in", DiscreteInputNode); + +// On close, detach the interrupt (if we attaced one) and clear the interval (if we set one) +DiscreteInputNode.prototype.close = function () { + if (this.interruptAttached) { + bs.detachInterrupt(this.pin); + } + if (this.intervalId!= null) { + clearInterval(this.intervalId); + } +};