Pew Pew Laser Blog

Code. Glass art. Games. Baking. Cats. From Seattle, Washington and various sundry satellite locations.

tinylab Flashlight.

8.2.2017

Photograph of a tinylab - an all-in-one arduino-compatible prototyping board. I've been fiddling around with my tinylab - an all-in-one prototyping board with an embedded Leonardo and a fair selection of components. I'd already got it working with Node and Johnny-Five. Next I wanted to do something which demonstrated interaction between the software and some real-world conditions.

Note that my tinylab (perhaps because it's an early crowd-funded version) doesn't have the breadboard shown in the current production versions of the tinylab. No worries - a mini breadboard (without the connector tabs) fits in there perfectly.

I made a "flashlight" - where an LED gets brighter when the hardware detects less ambient light. Since all the components on the tinylab are already built in, I didn't have to do any wiring. It's pretty easy to test by covering the photoresistor with your finger. Here is the code:

var five = require("johnny-five"), board, photoresistor;
var board = new five.Board();

board.on("ready", function(){

  var led1 = new five.Led(10);

  photoresistor = new five.Sensor({
    pin: "A2",
    freq: 500 // Data is polled every half second
  });

  maxLight = 750 // Set this to the "high" value of light in your room.
  minLight = 250 // Set this to the "low" value of light in your room.
  lightRange = (maxLight - minLight) // Will change for different rooms.

  photoresistor.on("data", function() {

    currentLight = this.value;
    ledValue = (((currentLight - minLight) * 255) / lightRange); 
    ledValue = Math.max(ledValue, 0);  
    ledValue = Math.min(ledValue, 255);

    console.log("Photosensor: " + this.value + "     ledValue: " + ledValue); 
    led1.fade(ledValue, 500); // Smooth transition of LED brightness

  });

});

You'll need to set the maxLight and minLight values for your environment.

With this experiment, you now have a way to read a value from your environment, report it to a computer, and act on it.

Subscriptions.

7.13.2017

I recently bought digital subscriptions to some "newspapers" (Seattle Times, NYT, WaPo) because I believe that creators should be paid for their work, that the news media is important in these political times, and because I wanted to move the motivation equation away from "ads and eyeballs". But I'm kinda disappointed at the less-than-premium treatment of paid subscribers by these organizations. Here are some examples of what I do not want:

Common Resume Feedback.

6.23.2017

A resume is a marketing document. Its job is to get you a phone screen or interview. During that interview, the resume can guide the conversation. Each bullet point should be able to start a story which demonstrates the specific ways in which you are awesome.

When I was unemployed a number of years ago, I learned a lot about resume writing from books, articles, and especially the career counselor that I saw. Because of this, I've offered to review friends' resumes. After a few rounds of this, I've put together the common pieces of feedback that I've shared:

Orphans and Widows in Wider CSS Contexts.

6.6.2017

Currently, orphans and widows aren't supported unless you're working inside paged media or columns. Phooey on that - I've got a few use cases where it would be nice to use it in other contexts.

Multiline Headline.

Here is a multiline headline inside an element whose width leaves just one word on the bottom line: Screenshot of a multiline headline in a width that leaves one word on the bottom line. See a demo. It would be nice if a declaration of orphans: 4; on the headline caused the browser to reflow the text so that 4 was the minimum number of words remaining in the bottom line of the paragraph.

Flexbox.

Here is a group of images arranged with flexbox, and just one lonely element stretched at the bottom of the group: Screenshot of images arranged with flexbox, with one element stretched at the bottom of the group. See a demo. It would be nice if a declaration of orphans: 2; on the flexboxed element caused the browser to try its best to arrange the child elements so that 2 was the fewest number of children at the bottom row.

Advice for Speaking.

5.16.2017

Here is a collection of some of the best pieces of advice for speaking at a conference that I've given and received over the last year:

Here are some HTML-based slideshows frameworks that you can use:

More advice:

Jim's Artichoke Spinach Dip.

4.25.2017

Artichoke spinach dip in a casserole dish I've got a friend named Jim who is pretty skilled in the kitchen. I've stolen and modified this recipe for artichoke spinach dip from him; it's a creamy warm dip which I often make when hosting friends for the yearly gluttony and football game extravaganza. Reminder to self - many of the ingredients can be bought at Trader Joe's.

The STEMTera Breadboard and Johnny-Five's five.Leds.

4.7.2017

The STEMTera Breadboard is a nifty combination Ardunio (Uno R3) / breadboard. It has a Lego-compatible backside and it's available in black, white, and pink. When I got mine, of course the first thing I did was get it set up to run with Johnny Five. The StemTERA breadboard with some resistors and LEDs installed.

Basic Functionality / Hello world

Making an LED blink is the Hello world! of hardware. It's common to just use an Arduino's onboard LED on pin 13. Here's what you do to get up and running from scratch:

Red and Green LEDs

Fritzing diagram of StemTERA breadboard with LEDs and resistors installed. Now let's add external LEDs (and protective resistors of course). Build your circuit as shown here, using 2 330? resistors, two 3mm LEDs, and two jumper wires. This is the magic of the StemTERA breadboard - the circuit doesn't need to hop back and forth between the breadboard and the external Arduino.

Here's the code - store it in a file and run it as with the first block of code.

var five = require("johnny-five");
var board = new five.Board();

board.on("ready", function() {

  // We can address them separately, or together in leds
  var red = new five.Led(6);
  var green = new five.Led(5);
  var leds = new five.Leds([red, green]);

  green.off();
  red.on();
  leds.blink(1000);

  this.repl.inject({
    leds: leds
    // leds.stop() // Stop the strobing
    // leds.off // Turn them both off
    // leds.stop().off(); // Combine!
  });

});

You should see the red and green LEDs alternating between on and off every second, and only one of the LEDs will be on at a time.

The interesting thing about this code is that it uses the Leds class - which allows us to control all the LEDs at the same time. At first, the green LED is off, and the red one is on. Then we blink the leds class; flipping the on/off state of each LED at the same time. You could use this to easily control many more LEDs.