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Using Arduino to cause email, SMS, etc, to be sent

Using the clever, free, IfThisThenThat service
Written for people new to IfTTT.com

I've "known about" IfTTT.com for years. Just never got around to playing with "If This, Then That" before.

But then I saw a note at Sparkfun, and three days went out the window! That link led me to an earlier one about a similar... project, which gave more detail.

IfTTT (at the heart of both) is BRILLIANT!

Like many brilliant things, it has so many sides that it can be a bit tough getting started. Try this little project if you have an Arduino or ESP8266 or similar which is connected to your LAN (be it by WiFi or cable), and you know about the issues of getting a webserver visible "to the outside world". We won't be creating a web server, but we need a DDNS solution in place, and all the usual firewall, etc, issues solved. (If you can run a webserver, an Arduserver, for instance, the hardest bits of what follows are dealt with.)

We're going to create (in Arduino) a device with a button. When the button is pressed, a IP/TCP "Post" message will be sent off to the nice people at If This Then That. When it gets there, it will cause an email to be sent, due to things we will set up before we press the button. (They only need setting up once.) (I believe you can have the process send an SMS just as easily, but haven't explored that, personally.)

FIRST... you may want to set up one, or even two, new "disposable" email accounts. The first needs to be with Gmail. Google will know about your IfTTT account, and that email address will be known to IfTTT. (Indeed, your IfTTT account will be tied to it.)

You may wish to set up a second disposable email account which can forward emails to a third account. Happily, the third account would typically be one of the accounts you routinely monitor. (And you would have no every-day need to visit either of the first two accounts.)

We'll come back to the email accounts in a moment.

IfTTT always boils down to the "recipes" which you create.

A recipe is just a rule for something happening if certain circumstances arise.

Our recipe, in essence, is....

IF THIS: (a certain message reaches the IfTTT.com servers) THEN, do THAT, "that" being:" send an email, as specified within the recipe. ("Specified": Recipient and text in the message.)

Now... you could have the recipe send the email to the Gmail account that your IfTTT account is attached to... if you look at incoming emails to that eddress. (The email will be SENT FROM that email account, by the way. Consider the security implications, which will be as varied as your use of this system.)

However, you can ALSO have the recipe send the email someplace else.

And if that "someplace else" can forward emails, you can "break the chain" between "you" and your IfTTT activity.

So!... The recipe can send an email. That's the "That" (sort of, for now) taken care of.

The "this": Once the recipe is set up, if you were to send, by whatever means you wish, a message to (something like)...


.. then a recipe in my IfTTT account would cause an email to be sent to me.

"... send, by whatever means..."

Just sticking it into the address edit box on an ordinary browser would suffice. (Very handy for testing purposes!)

Let's take a moment, get ahead of ourselves, and look at that in detail.

The following will always be just what you see here...


Then will come the name of one of the "applets" you have defined (with a recipe) on your IfTTT page. I created something called "door_status", for some wants I had one day. This example (almost) uses that applet.


then, always, as this....


... and finally, the "key"... Lots of gibberish. I've replaced a bunch of it with the "...."


That's it! Put that in a browser, and the "This" part of one... or many... recipes will say "Oh! It Happened! I need to do the "That"".

The magic or the "This" being seen, and orders to effect the "That" all happen in IfTTT's servers. (The service is free, by the way.)

(I'll show you the details of creating the recipe later.)

The thing to create the "This" event

Sending the thing that creates a "This" moment from a web browser, by hand, would have few uses outside of your development work. Hence the place of the Arduino, or ESP8266, or other silicon brains, in the scheme of things.


For our demo, I'm using a Sparkfun ESP8266 "Thing" (another recent (12/16) great enthusiasm!)

ALL you need, besides the device itself, and the software I am about to discuss, is a "doorbell" type switch (SPST momentary) which will connect D4 to ground when it is pressed.

And then there's the software....

This listing isn't tested yet. The SOFTWARE is tested... but publishing it on the internet is fraught with "issues". I would be very grateful if you would contact me, if you are able to use this "as is", or with notes on flaws needing fixing.

Nota Bene: The code won't run exactly as you see it. You have to "tweak" it, supplying things like your WiFi's SSID, and the password into your WiFi connection. This is also written to "put" the ESP8266 at a specific LAN address (192.168...), and to use a specific port. Those things will need setting. And last, but not least, you need to tweak the name of the recipe it will trigger, and supply YOUR key for that. Search on "q-FixThis" to find the pages which need tweaks. qTO BO INSERTED!!


 * If you see this with password or IfTTT key in it, PLEASE
 * contact me...
 * http://sheepdogguides.com/ctact.htm

 See messages to serial monitor for official name, version.
     (search on "gotoVers"

 Lightly adapted from....


 Example created by Rui Santos

 All the resources for this project:

 Rui said "Based on some ESP8266 code examples"

#include <ESP8266WiFi.h>

WiFiServer server(1203);

//Block 1 of 2 to set static IP address
IPAddress ip(192, 168, 0, q-FixThis);
IPAddress gateway(192,168,0,1);//These probably the same in most cases
IPAddress subnet(255,255,255,0);These probably the same in most cases

// WiFi Definitions //
//Tweak next two for your WiFi environment, and take
//  care not to tell people who shouldn't know
//  what settings you've supplied to the Thing...
const char* ssid = "q-FixThis";
const char* password = "q-FixThis";

//Tweak next with the name of the "This" element you
//  are creating. (You get to choose the name, but what's
//  here, and what's provided for in your IfTTT account
//  must match,.... and.....
//The "key" for the trigger. (This will be discussed later
//  in the essay this listing appears in.)
const char* apiKey = "q-FixThis";
const char* triggerName = "q-FixThis";

const char* host = "maker.ifttt.com";

int button_pin = 4;
int OutPutWithLED = 5;//(Use 5 to drive onboard LED of Sparkfun ESP Thing.)
volatile int state = false;
volatile int flag = false;
//"Door" used throughout in places where "switch" might have fit context better
const char* door_state = "closed";//Assumed switch to connect button_pin to ground is OPEN
  //when program initiates. <<double check this one! <<

unsigned long previousMillis = 0;
const long interval = 3000;

void changeDoorStatus() //This happens after interrupt...
    unsigned long currentMillis = millis();

    if(currentMillis - previousMillis >= interval) {
        previousMillis = currentMillis;

        state = !state;
        if(state) {
            door_state = "opened";//was "opened
            door_state = "closed";
        flag = true;

}// end of changeDoorStatus()

void setup() {
    Serial.println("Preparing the Door Status Monitor project...");
    //gotoVers (target for searches)
    Serial.println("Program: SendIfTTTTriggerCode");
    Serial.println("(I.e. this program will send the trigger code to make an IfThisThenThat recipe happen.");
    Serial.println("Version: 11 Feb 17");
    Serial.println("(Started 10 Feb 17... my first IfTTT day.)");
    Serial.println("Inspired by a note in a routine Sparkfun mailshot.");
    Serial.println("This code almost the same as example in...");
    Serial.println("Preparing the Door Status Monitor project...");

    pinMode(button_pin, INPUT_PULLUP);
    pinMode(OutPutWithLED, OUTPUT);

    //My thanks to...
    //... and a tip of the hat to Jeremy Rudge, who would be so pleased, for
    //"introducing" me to interrupts. I've never used one in a program before!
    //And to...
    //... for, in respect of the Sparkfun ESP8266:
    //"Arduino core also supports interrupts on any pin with the attachInterrupt() function."

    attachInterrupt(digitalPinToInterrupt(button_pin), changeDoorStatus, FALLING); //Was "CHANGE". Interrupts: Very cool. Story for another day.

    Serial.print("Connecting to ");

    //ADDED TO DEMO BY TKB... 2 of 2 to set static IP address
    WiFi.config(ip, gateway, subnet);

    WiFi.begin(ssid, password);

    while (WiFi.status() != WL_CONNECTED) {

    Serial.println("WiFi connected");
    Serial.println("IP address: ");

void loop() {
          Serial.print("Connecting to ");

          WiFiClient client;
          const int httpPort = 80;//This is port at destination... not of sending ESP8266
          if (!client.connect(host, httpPort)) {
            Serial.println("connection failed");
            }//of "if (!client.connect(host, httpPort))

          digitalWrite(OutPutWithLED,LOW);//TKB addition... to confirm to user
             //that a POST is happening.

          String url = "/trigger/";
          url +=triggerName;
          url +="/with/key/";
          url += apiKey;

          Serial.print("Requesting URL: ");
          client.print(String("POST ") + url + " HTTP/1.1\r\n" +
                       "Host: " + host + "\r\n" +
                       "Content-Type: application/x-www-form-urlencoded\r\n" +
                       "Content-Length: 13\r\n\r\n" +
                       "value1=" + door_state + "\r\n");
          flag = false;
      } //end of if(flag)...
}//of Loop

Right! That's the code. Shove it into an ESP8266. Watch the messages on the serial monitor. Hook up the switch.

If This, Then (do) That

Right... assuming your email addresses are in place, off to IfTTT.com

Click "Sign Up", and supply the Gmail email account you want to use with IfTTT, and password. (At this stage, I'm not sure if that's the email account's password, to "let you in" to the next stage of signing up, or your chance to define the password which will control your IfTTT account. I think it's the latter. (If someone following these notes could let me know, I'd be grateful.

Sidebar: Along the way of all this, you will encounter three logos built around an "M".

There's the IfTTT "Maker" logo. (You have an IfTTT "Maker" account as part of your IfTTT account.) Then there's the "M" logo of Gmail. Your IfTTT account CAN be tied to a Gmail eddress (and should, to give you access to things you can't do unless it is), but it is only "connected" in that you signed up to IfTTT off of a Gmail eddress. AND, in the course of using your IfTTT account the way I will describe, each will become aware of the other. But IfTTT isn't (yet) just a sub-division of The Evil Empire. And then, there's the "M" logo of Makezine... nothing to do with any of this, but IfTTT projects do get discussed there. (Sidebar ends)

Once you have your IfTTT account, if you want a simple exercise to get started with, use a TIME "This" and a GMAIL (not EMAIL) "That". If you are ready to go at, say, 9:18, set up "If (time is 9:30) THEN (send me an email)

But! For what I am excited about, you have to go a bit fancier.

Start a new Applet (My Applets/ New Applet)

(Click on the blue "+this" to access the "specify the 'this'" page.)

Type as much of "Maker" as you need to into the search bar to filter the alternatives down. You want what's on the right, below...


The second page looks like a mere "help" page. Says "Receive web request...". But the "help" text is actually a button for getting to the NEXT page....

... Where you will be asked to name the event. Keep it simple for now. For this time, use "My1stTrigger". You will, over the years, make many, if you find you like IfTTT. What you put here is what you put in for q-FixThis in...

const char* triggerName = "q-FixThis";

... in the program in the ESP8266.

For now, that's it, as far as the "This" part. The wizard will take you on to the "set up the 'that'" part. And for that, in our example, select a GMail (not mere Email) "action". That takes you to a button for "Send an Email". (I.e. "Set things up TO send an email.) Fill in a "To" eddress. You don't NEED to tinker with the rest, so, for now, probably best to leave the default entries. (You CAN alter these things.... just put your insertion point in the field and start typing.)

Once the screen is as you want it, click "Create Action"... and you are "done". Well. Your action is created, anyway. There's a "Check Now" button... but that merely checks SOME aspects of the new recipe. (You CAN, of course, go back and edit the recipe at a future date. N.B.: The text in the first box is JUST DESCRIPTIVE... and isn't updated automatically if you change a parameter of the applet.)

You also need to go along to https://ifttt.com/maker

Click on "Settings" (upper right), and you'll get something like...

Account Info

Connected as   (your IfTTT user name... defaults to first part of eddress)
URL  https://maker.ifttt.com/use/LongCodeOfGibberish

Where I've shown "LongCodeOfGibberish", you will have... what it says.

Make a careful note of that. It will be your LongCodeOfGibberish not only for this recipe, but for others in the future. Keep it SECRET.

Now, just in an ordinary browser, try to access....


... with LongCodeOfGibberish replaced with what was on your screen. You should get...

Congratulations! You've fired the tmp_del event

... AND an email should turn up, as per the "That" you assigned. (Give it a little time... it may not turn up "instantly". Give it maybe five minutes if you think it "ought" to be okay? (The process completes a lot faster, usually, though... even with my complex system of forwarding emails.)

Earlier, I told you how to fix the...

const char* triggerName = "q-FixThis";

... line in the code for the ESP8266. You will probably have guessed that the "LongCodeOfGibberish" goes in place of q-FixThis in...

const char* apiKey = "q-FixThis";

Once those are fixed, and the ESP8266 up and running, pressing the button should...

1) Take the place of using a browser to "do"...


... doing it whenever you press the button you wired to ground D4.

And, just as when you did it with the browser, IfTTT, when it receives the "thing", should send off the email you specified.


I hope you find all of that cool? 'Cause I haven't time or energy just now to "explain" it all. Sorry! Thank you for stuggling through with me; I hope your IfTTT recipe is working?

For the future

Not only can LAN connected Arduinos, including ESP8266s be the source of a trigger ("this") into an IfTTT recipe, programmed differently, they can effect the action.

And the good news is that you get a double reward for struggling through the above. Sending a "do it" command to an internet connected device, sending a command as the "That" of a "If this then that" recipe is EASY... if you've got through all of the above. And the link in the previous sentence will take you to a tutorial on setting up such a recipe!

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