controlling Arduino via sms (text msg)

I shouldn't say SMS, because technically I am using email, but either way, I thought I would share.

Some background.

I live in an old apt building that has a doorbell type system for opening the front door to let people in. You press a button, and the strike is magnetized, allowing someone to push the front door open. I wanted to be able to control this by sending a txt message. A good project for arduino.

I am going to be brief with my process; if anyone wants details, i can share. First, I built a linux box. Next, I installed Exim (MTA) and procmail and fetchmail. Fetchmail grabs email via POP3 from a gmail account. once the email is local on my system, procmail scans the body of the email and if it finds certain expressions, it runs a shell script. The shell script sends variables to Arduino via a program written in C over USB.

What it boils down to is i send a txt message to a certain gmail addy, fetchmail grabs it (i have a script that checks the gmail acct every 5 secs), procmail understands I sent a "open door" request and fires the app that sends a message to arduino to close a relay for 2.5 seconds, thus opening my door.

This was my first project with Arduino and I had a blast figuring it all out!

A very cool sounding project. I guess the computer is within your apartment? At first I thought you would have to put it down by the front door, but then realized it could all be in your space.

I suppose you have some security steps implemented? I guess you are fine unless the gmail address gets out. You wouldn't want internet wags opening your front door at all hours of the day or night. It would be nice to be able to give the address to trusted friends so they can let themselves in. You can easily change the special phrase send in the email to control who can still get in.

I bet you will enjoy using this project! Once your neighbors find out, they will be asking how much for one of their own! Just change your code to handle and log multiple email addresses or different special phrases and then charge each neighbor per use. :wink:

indeed.

The pass code changes every hour, but is easy for someone to figure it out if they know what hour it is and can do some quick math.

Also, every person that uses it gets logged by a unique identifier in their code. When the door opens, a msg is sent to my phone with the user's name. So far it has been a hit with the neighbors.

Sending junk to the gmail address, or anything that isn't the correct code, is logged as well, along with where it came from.