Recipe for Controlling an LED and Relay Using Text/Email Messages
This recipe demonstrates how to control multiple Devices using text/email messages. Here we will control and LED and a relay, but the recipe could be changed to support most any Device and any number of Devices. Each time a message is sent, it will be acknowledged with a return message, so the sender knows what happened.
For this recipe, you will need:
You need an email account to which you can send messages to via SMTP and receive from using POP. Most email accounts support SMTP and POP interfaces. If you look on your provider's support page, you should find addresses for sending and receiving messages such as "smtp.provider.com" and "pop.provider.com". Once you know these addresses, you can use your account name and password to send and receive messages.
The address where your messages will be sent can be any email address. It can also be an email address for a text message (see the Email Addresses for Texting section). You can add additional addresses using the addEmailAddress Script.
Unlike configurations which only send messages, this Recipe can receive and respond to messages as well. Receiving requires that the Recipe poll your email account for email. Don't use an email account which has email you wish to keep, or which is receiving email you wish to read. When this Recipe picks up the mail, it cleans out the mailbox. It will act upon messages from users it recognizes, but all the messages it receives will be deleted.
You can find the Script in the Scripts "examples" area. The Script is called "led_and_relay_texting.script". The Script is as follows:
To run this Script, you need 8 parameters: arduino_port, pop_host, smtp_host, smtp_port, ssl_enable, user, password, and messaging_address.
The arduino_port parameter is the name of the USB port of the Arduino. On *nix hosts, the USB port name is in the "/dev" directory. To see the devices in order of their creation, type "ls -lrt /dev" at a shell prompt and look near the bottom of the list for your Arduino's USB port.
The pop_host is the name of the POP server hosting the email account, and the smtp_host and smtp_port are the name and port of the SMTP server hosting the email account. ssl_enable determines whether SSL will be used when talking to the server. The user parameter is the user name of the email account on the server and the password parameter is the password for the email account. The messaging_address is the email/texting address of the device that will be controlling the system.
As an example, for an Arduino at USB port "/dev/cu.usbserial-00002006", an email server using SSL with name "email_server" with an email account of "user" and a password of "secret", and a controlling device which is a Verizon cell phone with phone number 111-555-1212, the Script parameters are:
Running the Script
Run the Script above. Go to the Device Explorer, click on the Arduino's "led" terminal, and enter
This recipe uses a Wired Messaging POP Device. The Wired Messaging Device supports multiple outputs and inputs, so we can control multiple devices with it. In order to tell the Device which output terminal we are addressing, messages to the Device have 2 values - a terminal name and a value. To turn the LED off, send a message back to the device that looks like this:
Email Devices, by default, quote their output values. In this recipe, we don't want quoted values, we want unquoted
Try sending something to a nonsensical Device. For example, send the message: