raspiTemp.py

Raspberry PiのCPU温度をAWS IoTにパブリッシュするサンプル

var awsIot = require('aws-iot-device-sdk'); // AWS IoT SDK
var moment = require('moment'); // Date library // moment
var exec = require('child_process').exec;

// constant parameters
const DEVICE_NAME = 'dev1';
const TOPIC = "raspi/temp"; // MQTT TOPIC
const REGION = 'ap-northeast-1';

// device config.
var device = awsIot.device({
  keyPath: './cert/private.pem',
  certPath: './cert/certificate.pem',
  caPath: './cert/rootCA.pem',
  clientId: DEVICE_NAME,
  region: REGION
});

// get CPU Temp. from Raspberry PI
function getCPUTemp(callback) {
  exec('cat /sys/class/thermal/thermal_zone0/temp', function(error, stdout, stderr) {
    if (stdout) {
      var value = Number(stdout) / 1000.;
      console.log('stdout: ' + value);
      callback(value);
    }
  });
}

// publish CPU temp
function publish_cpu_temp() {
  getCPUTemp(function(value){
    var message = {
      "device": DEVICE_NAME,
      "sensor": 'raspi',
      "time": moment().format(),
      "temp": value
    };
    message = JSON.stringify(message);
    console.log("# Publish: " + message);
    device.publish(TOPIC, message); // publish
  });
}

// loop for publish
setInterval(function() {
  publish_cpu_temp();
}, 10 * 1000); // per 10sec

// event for device "connect"
device
  .on('connect', function() {
    console.log('# Connected to Message Broker.');
  });