You can read incoming data from the serial port where we wrote data using the Python script in the previous section using Arduino. The following Arduino sketch will read the incoming data from the serial port and turn on the PowerSwitch Tail if it finds 1, and turn off the PowerSwich Tail if it finds 0.

The sample code, B04844_07_01.ino, can be found in the Chapter 7 codes folder, so you can copy and paste it on a new Arduino IDE and upload it to your Arduino UNO board.

Connecting the PowerSwitch Tail with Arduino

Connect the PowerSwitch Tail to your Arduino UNO board, as shown in the following Fritzing diagram. For this project, we will use a 240V AC PowerSwitch Tail:

1. Using a hook-up wire, connect the Arduino digital pin 5 with the PowerSwitch Tail positive (+ in) connecter.
2. Using another hook-up wire, connect the Arduino ground pin with the PowerSwitch Tail negative (- in) connector.
3. Connect a 240V AC light bulb to the LOAD end of the PowerSwitch Tail.
4. Connect the LINE end of the PowerSwitch Tail to the wall power socket and make sure that the main's electricity is available to the PowerSwitch Tail.
5. Using a USB A-to-B cable, connect the Arduino UNO board to the computer or laptop on which you wish to run the Python script. Make sure that you attach the USB cable to the correct USB port that is mentioned in the Python script.
6. Connect your computer to the Internet using Ethernet or Wi-Fi.
7. Now, run the Python script using Windows Command Prompt.
8. Log in to your Twitter account and create a new tweet including the text, #switchon. In a few seconds, the light bulb will turn on. Now, create a new tweet that includes the text, #switchoff. In a few seconds, the light bulb will turn off.

   Tip

   The drawback to this system is that you can't send the same Tweet more than once, because of the Twitter restrictions. Each time, make sure you create different combinations of text to make your tweet, and include your control word (#switchon, #switchoff) with it.