102-air-quality-sensor-email

ESP8266 over the Web: Getting started with IoT System Architecture

Project Goal

The use scenario of this project.

• Send an alert message by email when the air quality is not good
• Lean how to invoke SendGrid APIs

This project shows how to extend devify-server biolerplate to send an email. Please read Devify to understand Devify in a bit before continue to this project.

Prerequisites

0. Understanding 101-air-quality-sensor-console-print

1. This project uses SendGrid APIs for sending emails. Please signup and get your own credentials at SendGrid.

2. Please copy config.json.example to config.json.

Getting Started

Please open config.json and put on your username and password of SendGrid.

var server = require('devify-server').coapBroker;

// The email utility
var email = require('./utilities/email');

// Sendgrid credentials.
var fs = require('fs');
var credentials = JSON.parse(fs.readFileSync(__dirname + '/config.json'));

// Last time we have sent an email.
var last = 0;
        
var onmessage = function(message) {
    // Parse strings to JSON object.
    var obj = JSON.parse(message.data);

    // Put a timestamp in the message
    var now = Math.floor(Date.now() / 1000); 
    obj.timestamp = now;

    // Don't send too many emails.
    if (now - last < 60)
    	// We have sent an email in 60 seconds.
    	return;

	email({
		credentials: credentials,

	    from: 'jollen <[email protected]>',
	    to: 'jollen <[email protected]>',
	    replyTo: 'jollen <[email protected]>',
	    subject: 'ESP8266 Air Quality',
	    text: JSON.stringify(message.data),

	    success: function(message) {
	    	last = now;
	        console.log('Email sent: ' + last);
	    },
	    error: function(err) {
	        console.log('Email failed: ' + err);
	    }
	});
};

server.start({
    onmessage: onmessage,
});

Please replace from, to, replyTo, subject, and text with yours. The text property is the text context of this email.

NodeMCU

The full source list is as the following.

-- Configure the ESP as a station (client)
wifi.setmode(wifi.STATION)  
wifi.sta.config("<SSID>", "<PASSWORD>")  
wifi.sta.autoconnect(1)

-- Create a CoAP client
cc = coap.Client()

-- Make a POST request
uri="coap://192.168.0.100:8000/object/12345678/send"

-- Setup a timer to send ADC data
tmr.alarm(0, 8000, 1, function() 
    buf = 
          "{" ..
          "\"quality\":" ..
          adc.read(0) ..
          "}"
    
    cc:post(uri, buf)
    print(buf)
end)

The work of modifying the code is just the same with the chapter 101-air-quality-sensor-console-print.

Please read Quickstart to run this project.

Next

• 102-air-quality-sensor-dropbox