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Lab #2

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Wendy Ju edited this page Feb 7, 2018 · 47 revisions

In this Lab, we will use the Interaction Engine for an interactive webcam application.

Overview

  1. Set up Arduino connection
  • Connect Arduino
  • Flash sample Blink.ino program.
  • Check that Arduino is running program.
  1. HelloYou test
  • Flash helloYou firmware to Arduino.
  • Run the node program.
  • Test the functionality with a remote browser.
  1. Distant Pictures
  • Fork the distant-picture example project.
  • Plug the webcam into the Pi.
  • Run the node program.
  • Test the functionality with the remote browser.
  1. Make your own variation on this lab assignment: Change the behavior of the interaction.

Detailed steps

  1. Set up Arduino connection
  • You will need to power the Raspberry Pi with the AC adapter because you will need the USB cable from the class kit to connect the Pi to the Arduino.
  • Physically connect Arduino to the Pi using the USB cable.
  • Flash the sample Blink.ino program to make sure the connection to the Arduino is sound. (We will go into more detail on how to program the Arduino, compile code, etc. in the next lab.)
    • Login into your Raspberry Pi.
    • In the ~/sketchbook/blink directory, type make upload to flash the pre-compiled Blink.ino code to the Arduino
pi@ixeXX:~ $ cd sketchbook/blink
pi@ixeXX:~/sketchbook/blink $ ls
blink.ino  build-uno  makefile
pi@ixeXX:~/sketchbook/blink $ make upload

The Arduino LEDs should flash rapidly while the code is being flashed onto the Arduino, and then the red onboard LED should blink on and off at a 10 Hz rate.

  1. HelloYou test

We have demonstrated this example in class. We will have a button connected to an Arduino attached to the IxE via a USB cable change the background color of our webpage. Then we can use a button on the webpage to turn an LED on the Arduino on and off.

  • Set up the Arduino button circuit (We will also go deeper into the electronics in the next lab.) On your breadboard, make this basic button circuit connected to pin 2 of the Arduino. (The LED is built in on the board and connected to pin 13.) David, can we add a photo of the board here, too?
  • Flash the pre-compiled HelloYou.ino code onto the Arduino.
pi@ixeXX:~ $ cd ~/sketchbook/helloYouSketch/
pi@ixeXX:~/sketchbook/helloYouSketch $ make upload

Now that the Arduino code is uploaded, you should see your LED is off (because it isn't running the Blink sketch anymore).

  • Run the HelloYou webserver.
pi@ixeXX ~/sketchbook/helloYouSketch $ cd
pi@ixeXX ~ $ cd helloYou/
pi@ixeXX ~/helloYou $ ls
helloYouSketch.ino  package.json  public  README.md  server.js
pi@ixeXX ~/helloYou $ node server.js /dev/ttyUSB0
listening on *:8000
  • Test the functionality with remote browser. If everything is working, you should see a message in the terminal that the webserver is listening on port 8000.

Now, you can go to you web browser and type your 'ixe[hostnumber]:8000' in the address bar.

  • David add debug stuff
  1. Distant Pictures
  • Fork the 'distant-picture' example project On your IxE, fork and git clone the distant-picture example project.

pi@ixeXX:~ $ git clone https://github.com/**_YourUserName_**/distant-pictures.git

In the distant-pictures directory, install the basic components for the node server by executing npm install

pi@ixeXX:~ $ cd distant-pictures
pi@ixeXX:~/distant-pictures $ git clone https://github.com/**_YourUserName_**/distant-pictures.git
  • We are using the helloYou Arduino circuit and code, so no adjustment is necessary on the Arduino side.
  • Plug in the web camera
  • Check the web camera is working
  • Running the webserver with node.js First navigate out of the 'ArduinoCode' directory with 'cd ..'. Then run the code similar to last weeks assignment. However, we also need to pass reference to the Arduino port to the server. The command should look something like node server.js /dev/ttyUSB0.
pi@ixe05 ~/distant-pictures $ node server.js /dev/ttyUSB0
listening on *:8000

If everything is working, you should see a message in the terminal that the webserver is listening on port 8000.

Just like in the previous assignment you can now go to the browser to control the Arduino and webcam.

To shut down the server, type control + C in the terminal.

ledOFF
ledON
^C
pi@ixe05 ~/helloYou $
  1. Change the Interaction For this lab we want to you to extend the functionality of this basic setup. As a start, we want you to change its behavior so that it takes a picture whenever someone presses the physical button.

Class Resources

Overview Page

Resistor Color Codes, explained!

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