JavaScript: Arduino Bumper Switch Controlling a Led Tutorial

Welcome to the third tutorial in our series geared towards Arduino programming on Node.js, using the Johnny-Five framework. Get caught up here.

Johnny-Five is a Firmata based Arduino programming framework. See: JavaScript: Arduino Programming on Node.js.

In the first tutorial you created a program to control a servo via REPL; then, in the second tutorial you added a slider to control the servo. In this tutorial, we’re going to set the servo and slider aside and build a simple “on/off” switch with a bumper and an led:

New Parts list:

• Bumper Switch
• Led

Tutorial Requirements:

• One (1) Arduino Microcontroller Board
• One (1) 9V wall wart adapter plug or 9v battery harness
• Seven (7) Jumper cables: red (3), black (2), yellow (2)
• One (1) Any color Led
• One (1) Bumper Switch/Button
• One (1) 10k OHM

First, set up the hardware using this schematic as your guide:

Connect the following…

1. Bumper: Black > GND to Breadboard to 10k OHM Resistor
2. Bumper: Red > 5v to Breadboard
3. Bumper: Red > Breadboard to Bumper
4. Bumper: Yellow > Signal to Breadboard on grounded resistor
5. Bumper: Yellow > Breadboard to Pin 7
6. Led: Cathode > GND
7. Led: Anode > Pin 13
8. Microcontroller > USB
9. 9V Power

Assuming you’re using the actual repo, open up eg/button-bumper.js, or follow along here…

And that’s it!

Run node eg/button-bumper.js¹ and try tapping and/or holding the bumper down — the led should switch on and off as you press and release.

Remember to watch this space for more tutorials!

Note: There is a known issue in where the Firmata protocol layer has issues freeing itself on the serial line which results in the program hanging in the ready state. For now, ^C to kill the hanging program and simply run it again.

This entry was posted by Rick Waldron (@rwaldron) on July 17, 2012 in JavaScript, Node.js, Arduino, Johnny-Five and NodeBot.

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