Let's Make a Robot!

We're going to wire a button and LED to our Pi and play with them offline before hooking them up online

1. Open these tabs in your browser

johnny-five.io

https://github.com/nebrius/raspi-io/

https://github.com/nebrius/raspi-io/wiki/Pin-Information

2. Let's plug some stuff in!

Then we're going to wire an LED and push button to our Pi

2a. The LED

(diagram)

2b. The Button

(diagram)

3. Install Dependencies

Let's create a folder on our pi for code:

mkdir ~/code && mkdir ~/code/bot && cd ~/code/bot

Then, we're going to install johnny-five and raspi-io so we can start coding!

npm init -y
npm i --save johnny-five raspi-io

4. OMG YES FINALLY CODE TIME

Let's create a file for our code

nano exercise1.js

(name it whatever)

And start typing in the following code:

const Raspi = require('raspi-io')
const five = require('johnny-five')
const board = new five.Board({
  io: new Raspi()
})

board.on('ready', () => {
  let led = new five.Led('P1-19')
  led.strobe()
  let strobing = true

  let button = five.Button('P1-11')
  button.on('press', () => {
    strobing ? led.stop().off() : led.strobe()
    strobing = !strobing
  })
});

4b. Stop for a quick dance party because omg you just built a robot!

5. Using the REPL (Read, Eval, Print Loop)

add the following after the close of your button.on() call:

this.repl.inject({
    button,
    led
})

This allows you to access the LED and the button from the command line once your code is run-- run your code and wait for the prompt. While the LED is strobing, type in

led.stop.off()

then try

led.on()

This tool is super useful for debugging more complex johnny-five programs, so keep it in mind when writing your own projects!

Let's make a robot!