68 lines
2.2 KiB
JavaScript
68 lines
2.2 KiB
JavaScript
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module.exports = function(RED) {
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"use strict";
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var fs = require('fs');
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// unlikely if not on a Pi
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try {
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var cpuinfo = fs.readFileSync("/proc/cpuinfo").toString();
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if (cpuinfo.indexOf(": BCM") === -1) { throw "Info : "+RED._("rpi-gpio.errors.ignorenode"); }
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}
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catch(err) {
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throw "Info : "+RED._("rpi-gpio.errors.ignorenode");
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}
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var mcpadc = require('mcp-spi-adc');
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var mcp3008 = [];
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function PiMcpNode(n) {
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RED.nodes.createNode(this,n);
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this.pin = n.pin || 0;
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this.interval = n.interval || 1000;
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this.dnum = parseInt(n.dnum || 0);
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var node = this;
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try {
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fs.statSync("/dev/spidev0."+node.dnum);
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if (mcp3008.length === 0) {
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for (var i=0; i<8; i++) {
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mcp3008.push(mcpadc.openMcp3008(i, { deviceNumber:node.dnum }, function (err) {
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if (err) { node.error("Error: "+err); }
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}));
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}
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}
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node.on("input", function(msg) {
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var pin = null;
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if (node.pin === "M") {
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var pay = parseInt(msg.payload.toString());
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if ((pay >= 0) && (pay <= 7)) { pin = pay; }
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else { node.warn("Payload needs to select channel 0 to 7"); }
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}
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else { pin = parseInt(node.pin); }
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if (pin !== null) {
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mcp3008[pin].read(function (err, reading) {
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if (err) { node.warn("Read error: "+err); }
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else { node.send({payload:reading.rawValue, topic:"adc/"+pin}); }
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});
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}
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});
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}
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catch(err) {
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node.error("Error : Can't find SPI device - is SPI enabled in raspi-config ?");
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}
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node.on("close", function(done) {
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if (mcp3008.length !== 0) {
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var j=0;
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for (var i=0; i<8; i++) {
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mcp3008[i].close(function() { j += 1; if (j === 8) {done()} });
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}
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mcp3008 = [];
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}
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else { done(); }
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});
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}
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RED.nodes.registerType("pimcp3008",PiMcpNode);
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}
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