A Cornucopia Keyboard Options

Once I started looking, I found a lot of options for a custom keyboard.  In fact, I started seeing them everywhere.1 I found these offered as some combination of “media,” “macro,” “button,” “board,” “keypad,” and “keyboard.”  I’m offering this list in no particular order – other than how I noticed each one.

 "6 Key Macro Keypad" by @iHayri1

“6 Key Macro Keypad” by
@iHayri1

1. 6 Key Macro Keypad” by @iHayri1, ~$87

I found @iHayri1‘s keyboard in HackSpace magazine, issue #37, page 101.  If you don’t happen to have it lying around – no problem!  This magazine published by the Raspberry Pi Foundation gives away their digital version!  While on the pricier end of the keyboards, it’s got a lot of interesting features.  Six buttons, a media dial, an RGB LED under each key, a series of LED’s at the base of the keypad, and an LCD screen displaying each key’s current function.  I would have ordered this one, except it’s been out of stock for a little while.  :)

"NoodlePad" by @TheMadNoodle

“NoodlePad” by @TheMadNoodle

2. “NoodlePad” by @TheMadNoodle, ~$86

I found the NoodlePad by @TheMadNoodle on Etsy after searching for media keypads.  This is another beautifully designed board – eight buttons, knurled metal knob, mounted onto a shaped board and thick lasercut acrylic plate.  This was the first board I saw referencing “QMK” firmware.  This board is also offered in a “semi-assembled” state where the buyer supplies their own switches and keycaps.  If you’re going to fall down a rabbit hole on mechanical keyboards, the switches may be what get you.  The ordering options also offer “Cherry Red,” “Cherry Blue,” “Cherry Brown,” and “Cherry Black” switches.  At first I thought this referred only to the color of the switch underneath the keycap.  As it turns out, each color matches the little bit of plastic connecting into the keycap which in turn is associated with a different set of mechanical features for that particular kind of switch.  Maybe you want a key with more bounce, requires more force, or a more gentle touch.  That you can order your keypad with the exact keys you need says a lot about this maker and their product.

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3. “BYO Keyboard” by @travis_the_makr, starting at $36

I happened to catch @travis_the_makr showing off a prototype “BYO Keyboard” on Adafruit’s Show and Tell.  I should probably feel a little bad for hassling Travis to sell me one of these board immediately after his appearance on the show.  Intended as both a way to get started with soldering and programming as well as an actually useful final project. I kinda love the project is powered by an Adafruit Itsy Bitsy M0 so you can use either Arduino or CircuitPython.  I note QMK firmware support is a stretch goal.  :)  Don’t let this bare bones DIY kit without LED’s, knobs, and displays fool you.  If, like me, you’re only now embarking on your mechanical keypad journey and don’t have a drawer full of Cherry MX switches and keycaps, this is an excellent and affordable starting point.  Suffice it to say, I immediately pledged the Kickstarter and am really looking forward to playing with this project.

BigKnob by Leafcutter Labs

BigKnob by Leafcutter Labs

4. “BigKnob” by Leafcutter Labs, starting at $45

Of all the various keypads I’ve looked at, this was the very first one I ordered.  I opted for the version with the black steel case, wonderfully heavy metal knob, and asked the owner for some variation in the keycaps.  Craig shipped the keypad immediately and it arrived well packed in bubble wrap, only requiring that I pop in my choice of keycaps and apply the included sticky rubber feet.2 This keypad rocks four Cherry MX switches, a big hefty knurled metal knob, six RGB LED’s which glow through the lasercut acrylic base plate.  My configuration (with the metal case) was $62, including shipping.  While this is the only keypad I’ve actually used so far, it’s going to hard to top.

5. “8K Controller” by 2XLNetworks, starting at $32

Once I started tweeting about picking out some keypads, my buddy Pete told me about the “8K Controller” by 2XLNetworks.  This keypad has no LED’s, no metal knobs, no LCD displays – but it doesn’t need any of that.  It comes with a built-in USB cable, you can order it with pre-programmed with custom button assignments at no extra cost, reprogram it if you like, and it unlike a hipster clicky-clacky Cherry MX switch, it rocks arcade buttons.  If you need a bulletproof box that can stand up to repeated abuse at the hands of the public (perhaps for a photobooth, art project, school installation?), this is be the keyboard for you.

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  1. I’m reminded of the Baader–Meinhof phenomenon; after the first time you notice something, you notice it more everywhere []
  2. These are a great touch! []

Falling Down the Mechanical Keyboard Rabbit Hole

The Solace of Quantum (Mechanical Keyboards)

The Solace of Quantum (Mechanical Keyboards)

TLDR:  I’m going to try some mechanical keyboards to help me work from home and blog about my experiences.

I’m fortunate that I’ve been able to work from home this pandemic.  I’ve always made a special effort to make my work more “digital,” by scanning and organizing digital copies of important work documents.  In many ways working from home hasn’t required too many changes to my overall workflow.  My entire office and desk space shrunk to just a single laptop propped up on a plank of cardboard with some holes to help distribute heat.  I have to be more disciplined about creating digital notes, since I can’t cover my work space in post-its and illegible scraps of paper.  Two pairs of noise cancelling bluetooth headphones are are taking the place of four walls and a door to help me concentrate and communicate “I’m working” to the kids. 1  While I’ve gotten used to one medium sized laptop screen, in place of a dual monitor setup, the one thing that’s been extremely difficult is using a laptop keyboard instead of a full fledged keyboard.

Which brings me, dear reader, to the QMK or “quantum mechanical keyboards.”  The QMK is a keyboard firmware2 that allows you to create very customized keyboards and keyboard layouts.

A while back I wrote a Chrome extension to help me with some work related data entry tasks.  It works by intercepting some of the top row function keys, preventing their default actions, and replacing them with some macros.  This setup probably slashed the number of required clicks and keystrokes by 75%.  My fevered dream is for a custom keyboard which could cut this yet in half.

Now, if that keyboard also has some media controls and sweet RGB goodness, well, then, awesome.  Of course, this means I can’t just go order a keyboard off a shelf.  While there are plenty of neat custom and QMK keyboards, to really get the most out of a board, to get exactly what I need, I will need to roll up my sleeves and actually dive into the firmware itself.

Next up – which keyboards?!

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  1. Why two pairs?  I originally bought one for myself and one for my wife, but now I’m just using one while the other charges… []
  2. “Firmware” is nothing more than software built to run inside a piece of hardware []

PCB Design with KiCAD

It is pretty incredible that you can find a written or1 video tutorial on virtually any topic to learn anything.  Today, I’m particularly thankful to Shawn Hymel, Sparkfun, and Digi-Key for putting together their Intro to KiCAD video series on printed circuit board design.

This series took me from knowing nothing at all about PCB layout and design to ordering my very first board through OSHPark.  My first design isn’t anything amazing – it was basically a breakout board for an ATTiny85 to make it easier to build small projects. 

My first ATTiny hacked tap light was a mess.  I soldered wires directly to the microcontroller making it a real pain to update. ((I ask you – is this the work of a sane man?)) I soon realized my mistake and soldered an 8-pin socket in its place so I could reprogram the chip easily.

This is the alternative to a custom PCB – a rat’s nest of wires soldered to a chip

Mercifully, Shawn’s tutorial series got me up and running very quickly.  This post is not meant to be a tutorial for KiCAD, but more like a “lab notebook” for the workflow to create a board.  If you haven’t built a board yet, go check out Shawn’s series and follow along in KiCAD.  If you are a novice like me, you might find these notes helpful:

Eeschema

  • If you launch Eeschema separately from KiCAD, you can save different versions of a schematic.  Keeping old versions of design files is hugely helpful to me and if you launch KiCAD directly, the option to save different file names and versions is not available!
  • The keyboard shortcuts in Eeschema are great.  With just a few, it’s possible to really get around quickly.
    • “Shift-A” and left click to place parts 
    • “M” to move parts
    • “R” to rotate parts
  • It is necessary to add “PWR_FLAG” to both the power and ground lines.
  • Double check your connections work by clicking on the bug icon. 
  • Assign the parts you intend to use to match up with the symbols using the “Assign PCB footprints” icon.
  • Save your work and “Generate netlist” to have something the Pcbnew will be able to work with.

Pcbnew

  • First configure the Design Rules by going to Setup -> Design Rules.  Shawn pulled these KiCAD Design Rules from the OSHPark.com website.  KiCAD has apparently changed a little since the version used on the OSHPark website, but the settings are easy enough to identify and change.
    • Net Classes Editor
      • Clearance: 0.01.  Track Width: 0.01.  Via Dia: 0.03.  Via Drill: 0.015.  uVia Dia: 0.03.  uVia Drill: 0.015.  Diff Pair Width: default.  Diff Pair Gap: default.
      Global Design Rules
      • Minimum track width: 0.006.  Minimum via diameter: 0.027.  Minimum via drill: 0.013Custom Track Widths: Track 1: 0.03
  • Read netlist” to bring your design over from Eeschema.
  • Placing parts and drawing lines gets a lot easier when you fine tune the Grid.  I started with 5.00 mils at first, then smaller figures to place smaller parts and features.
  • Once the parts are arranged in Pcbnew, connect the ground and power lines using 30 mil traces and everything else using 10 mil traces.
  • Create the outline for the board cutout by clicking on “Edge.Cuts” and drawing with the “Add graphic lines” tool.  Starting with my second board, I began cutting the corners off, so that they were a little nicer to hold and 
  • Label things on the “F.SilkS” and “B.SilkS” layers using the “Add text”‘ button.  Since my boards are so small, I wanted the text to be a fair bit smaller than the default settings.  I edited the text settings by going to Setup -> Text and Drawings.  
    • Copper text thickness:  0.007.  Text height:  0.035.  Text width:  0.035.
  • Create a copper pour with Place -> Zone, then choose “F.Cu”2 and “GND”.3 and draw a box around your board.  Then repeat for the “B.Cu” and “GND.”

Again, I’m a total newbie at circuit design.  If I got something wildly wrong, please let me know.  :)

  1. More frequently these days []
  2. Front copper []
  3. Ground, natch []

Cheapest Easiest Easy Button Hack EVER

But... could it be even EASIER?!

But… could it be even EASIER?!

I’ve always liked the idea of the Staples Easy Button.  Not so much a button that says “That was easy,” but the idea of having an enormous button on my desktop that would do… anything at all.  Official “Staples Easy Buttons” used to sell for about $20 and are now only about $7.  But, this is still a lot to pay for a big button that I’d want to gut anyhow.  Recently I figured out a way to build a big useful button, very inexpensively.

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The secret sauce is … a tap light!  You can buy a pack of 4 big (10cm diameter) tap lights for under $4 and they’ll ship free as a “Prime add-on.”  For less than $1 each, you get a three AA battery holder, toggle on/off switch, a bright LED, all neatly organized into a big plastic button.  This button also has another “feature” which is missing from many other pricier options.  The dome over the light is white – which means you can put any color LED or, as I did, an Adafruit Neopixel inside and the dome will change color accordingly!

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Here are some pictures of the disassembled tap light so you can see if it would work for you.  I had originally bought these so that I could put a light right next to my newest 3D printer.123

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There’s actually quite a bit of room inside the tap light for a small project.  I was able to pack a Neopixel, a small buzzer, an ATTiny85, and a rat’s nest of wires.  I expect this project to take a lot of abuse at Maker Faire, so I applied a liberal amount of hot glue inside to hold the wires down and out of the path of the springs, switch, case, and the likely path of the button dome.

Once reassembled, there really isn’t any way to tell the button was hacked.  It looks identical to three other tap lights.  I just love that I was able to make use of the battery holder and existing switch inside the project.  The 4.5V supplied by the batteries is perfect for powering my ATTiny85 and lone Neopixel.  If you’ve got a junk drawer, you could probably build something very similar for about $2-3.4 As it is, I “splurged” by using $1 worth of Neopixel because I was being lazy and didn’t want to either wire up three sets of LED’s or track down three resistors to go with an RGB LED.  Even so, this is an incredibly cost-effective project enclosure.

15 Second Timer-Buzzer

15 Second Timer-Buzzer

In case it’s of interest to you, this project is the newest iteration of our 15 Second Timer-Buzzer from my daughter’s 15 Second Drawings project for Maker Faire Bay Area 2017.  The prior version used an Adafruit Circuit Playground, a 100mm Red Button, and a LiPo battery and probably cost around $40 or so. 5

All of the code is on Github. Basically, the buzzer flashes amber three times with a very short tone in between flashes, then turns green for 14 seconds, amber for one more second, and then turns red and buzzes angrily to let you know time is up.  I had written most of the code to work on an ATTiny45… until the code ballooned to a whopping 4560 bytes and I had to switch to an ATTiny85.6 If I had to build this over again, I’d solder in an 8-pin DIP socket for the ATTiny rather than mutilating the chip and hot gluing it directly to the inside.  ;)

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  1. I have a power strip next to it, but it’s fully utilized, I only need a little bit of light sometimes, and I was getting tired of holding a flashlight on it at night []
  2. In my tradition of naming my 3D printers after characters from Futurama, my Monoprice Mini Delta is named “Roberto.” []
  3. My prior 3D printers are Bender the MakerBot Cupcake CNC, Flexo the MakerBot Thing-O-Matic, and HedonismBot the Replicator 1 Dual []
  4. I figure about $1 for an ATTiny85 and $1 for the button.  Most people can find a way to scrounge an RGB LED or a few different LED’s, an old buzzer or piezoelectric disc, and some bits of wire []
  5. Not counting the gelato we ate, of course []
  6. What a waste!!! []

Paper Circuits: The Adventure Begins

While I’m a big fan of paper and circuits, I’ve never really given paper circuits/circuitry a shot.  Unfortunately, I have no good excuse for this.  (Fair warning:  I’ve been collecting links and ideas on this topic for several weeks now, and even though I intend to break up the post into more manageable chunks, I have a feeling this is going to be a doozy)

1. TapeTricity

Years ago Chris Connors, a STEAM educator/maker and friend, had posted some photos and videos about something called, “TapeTricity” and helped hundreds of kids as young as 3 and 4 years old build their very first circuit at Maker Faire 2013.  TapeTricity is all about making electronics accessible to people by showing them how to make real circuits using cheap and common components while removing the need for specialized tools and materials.  This system of designing circuits made use of several very interesting innovations: aluminum HVAC tape and paperclips along the edges to form electrical contacts.

1. Aluminum HVAC Tape – Benefits and Limitations

Back in 2013 copper tape was reasonably common in artistic settings for use with soldering stain glass.  However, the copper tape wasn’t readily available with conductive adhesive and tended to be more expensive than the aluminum HVAC tape used in Chris’ projects.  While the prices of copper tape with conductive adhesive have fallen over the last few years and conductive inks/paints have become more common, pretty much nothing is going to beat aluminum HVAC tape for price per project.  However, HVAC tape is not without its limitations.  The adhesive is a decent insulator rather than a conductor, the tape only comes in strips about 2 inches wide and must be torn or cut to much thinner strips, and has a tendency to curl at torn edges, and aluminum tape does not take solder well.1 I expect that the non-insulation properties of the underside of the aluminum tape could actually be very useful in conjunction with copper tape – to essentially make for circuit board traces that can cross over one another.

2. Taped Edges – Contact Points

TapeTricity components

As you can see from some of the photos above, the edges of the cards had foil tape wrapped over some edges which were then connected to some of the components.  The result is that the edges of the paper essentially become functional I/O pins.  The nifty thing about this is that it could allow TapeTricity cards to be wired/rewired/networked together.

3. Paperclips – Alternatives to Alligator Clips

Another interesting feature of TapeTricity comes from the use of paperclips.  Paperclips are ubiquitous and cheap23 and, with a little bit of wire, become cheap DIY alligator clips replacements.  While individual alligator clips aren’t that expensive (let’s say around $0.25 each?), the cost of providing a number of them to a room full of students would quickly add up.

These TapeTricity cards allowed kids to color and draw on one side of an index card – then bring their designs to life with electronics on the back and through the card.

4. Lessons from TapeTricity

  • HVAC tape is a great choice for paper electronics with a few limitations.  The adhesive is an insulator which allows HVAC tape to be leveraged in bridges and there aren’t easy ways to solder to it.
  • Edge conductive pads from HVAC tape allow for cards to be powered or networked
  • Paperclips and wire are a great cheap DIY alternative to alligator clips

2. Evil Mad Scientist Labs and Paper Electronics

Evil Mad Scientist Labs is one of my all time favorite open source arts/electronics designers/manufacturers ever.  Not only do they enable other people to realize their plans for world domination, they’re pretty cool people.  I had the good fortune to be able to visit Evil Mad Scientist Labs (now celebrating their 10th birthday!) a few years ago.

1. One Sided Circuit Board – paper, conductive ink, and soldering

Mobius Circuit - 21

While there Windell Oskay and Lenore Edman gave me a tour and showed off their awesome single sided mobiüs circuit board.4

2. Electronic Origami – several methods for electrifying paper

toner - 15

More recently, while researching for this blog post I discovered their simpler, but perhaps more spectacular, origami balloon circuit.  EMSL posted several possible methods for electrifying paper.  Since the post explains each of these methods in detail, I’ll only list them:

  • Using dry mount adhesive to glue aluminum foil to paper
  • Using an iron to fuse aluminum foil to freezer paper
  • Using an iron to fuse aluminum foil to the toner on laser printed paper
  • Lessons on resistors and simple LED/battery combinations inspired by LED throwies

This circuit is beautiful and eerily reminiscent of a certain other cube.  If someone hasn’t made an origami LED paper circuitry companion cube, well, this is just a thing that needs to exist in the universe.

3. Edge-Lit Cards

EdgeLitCard - 31

Another particularly cool post from EMSL is their piece on edge lit holiday cards.  The electronics are essentially the same as a simple throwie or TapeTricity circuit, but the use of scored sheets of plastic allow incredibly interesting display possibilities.

4. Lessons from EMSL

In no particular order, here are some of the lessons I’ve learned from EMSL:

  • The conductive ink in the mobiüs circuit has enough resistance that the LED’s don’t really require actual resistors
  • Electronic paper projects need not be merely two-dimensional and adding a third dimension can be truly transformative
  • Scored or scratched plastic plus paper and carefully designed LED circuits can create amazing display possibilities

3. Paper Circuits / Paper Circuitry / Electronic Notebook

Just before Maker Faire 2016 I saw a tweet from Jeannine Huffman showing off her development of a paper circuitry robot panda which would cost about $5 per student.

I was astounded by what Jeannine was doing.  Where TapeTricity was a great way to introduce kids to electronics, making those same electronics smart by adding a microcontroller could make those same pages smart and interactive.  Moreover, a TapeTricity project could be “leveled” up by just wiring the aluminum contact pads to a microcontroller.

1. Jeannine Huffman’s Notebook

I was fortunate enough to be able to catch up with Jeannine at Maker Faire Bay Area 2016 this year and we compared notebooks.  Here’s some pictures of her work:

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I regret that I didn’t take more pictures of Jeannine’s notebook, she’s been kind enough to post much of her designs on her website, her Twitter account, her Google Plus page, and in the 21st Century Notebooking Google Plus community.

2. Lessons from Jeannine Huffman

To just jot down some of the problem solving and ideas I noticed in the few moments when we compared notebooks:

  • Mixing off the shelf electronic components and circuit stickers with conductive ink, copper tape, and soldering
  • Incorporating electronic components, sensors, and microcontrollers with DIY sensors, switches, and other solutions
  • Melding a notebook and electronics – by sketching in, around, and through circuits to provide annotations and instructions
  • Finding a way to create a copper tape hinge that could survive repeated opening and closing of the notebook

4. 21st Century Notebooking

The ideas shared in the 21st Century Notebooking Google Plus community are just too numerous for me to do justice.  Since my blog posts are as much about me documenting my own discoveries as it is about sharing with you, gentle reader, perhaps you’ll forgive my jotting down just a few of the ideas found within a 30 second scan of this community:

  1. Paper electronics with mixed media arts crafts
  2. Paper electronics mixed with origami
  3. From +Jie Qi and @Chibitronics:
    1. Conductive fabric to create conductive hinges for use in circuits spanning more than one page in a notebook
    2. Light up paper helicopters
    3. Copper tape paper speakers
    4. UPDATE 10/26/2016: Jie Qi’s “paper-based electronics for creative expression” tutorials have some really great ideas for getting started with paper circuitry.  Frankly, this is to be expected from the lady who created Chibitronics and circuit stickers.  :)  These tutorials are great – and you can see exactly how she refined these ideas to become circuit stickers and the kind of skill building projects seen in Chibitronics books.  These tutorials include:
      1. basic circuits,
      2. paper battery holder,
      3. parallel circuits, soldering,
      4. making switches,
      5. blinking LED’s,
      6. pressure sensors,
      7. basic programming,
      8. fading program,
      9. blinking program,
      10. random program,
      11. sequence program,
      12. and a microphone program!

5. Project Daffodil (Update 10/26/2016)

Project Daffodil is the work of Sian Geraghty, Robert Foster, and Christine Ho as their graduate thesis project for the Masters in Multimedia Program at CSUEB.  Their project combines pop-up books, paper circuitry techniques, and 3D printing to provide an interesting introduction to electronics for kids.  When I saw them at Mini Maker Faire Rocklin on 10/5/2016 they had combined their work with an iPad app which could interact with some of their 3D printed models infused with conductive material.  They’ve been interviewed on the Make Magazine website and published a tutorial on building pop up paper crafts with electronics.

1. Lessons from 21st Century Notebooking, Circuit Stickers, and Project Daffodil

I think what I learned most out of these projects is that there’s a lot of ways to combine paper circuitry with other interesting and creative ideas like origami, paper crafts, greeting cards, pop up books, and 3D printing.

6. What’s Next???

Smart sketchbooks, electronic origami, and the ability to program anything.  With all these incredible designs, pieces of code, and ideas – where can we go next?

Well, I have a few ideas…

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  1. When I googled “how to solder copper wire to aluminum foil” the top result was a YouTube video which suggested applying a thin layer of oil to the foil, using a soldering iron with solder to heat up the foil, with the oil supposedly preventing the aluminum from oxidizing, then the wire could be soldered to the foil. []
  2. Or free when you are at a Kinko’s []
  3. Perhaps the better phrase is “complimentary”? []
  4. I hope you will, once again, forgive me as I present these items in the order of my discovery, rather than chronological order? []

What are the minimum parts necessary for an Arduino?

Outside a MintDuino, a book is a man's best friend

Outside a MintDuino, a book is a man’s best friend

It was hard for a beginner like me to imagine that an Arduino actually requires a whole lot less than all the stuff you would see on an Arduino Uno.  Assembling a MintDuino – and slowly pulling parts out to see what was really necessary – helped me understand what was truly critical to its operation.

Inside a MintDuino, it's too dark to read...

Inside a MintDuino, it’s too dark to read…

I found it useful to know what the (near) minimum necessary components of an Arduino were so that I could build a small project directly around just the chip and whatever critical parts were absolutely required to run the circuit.1 I wanted to build the circuit as small as possible – not to save on parts or cost, but to make sure everything could fit into an Altoids tin.23

As a side note, there is a very definite monetary benefit to figuring out how to build a minimal Arduino compatible device.  A brand new Arduino will run you about $30 – whereas soldering a chip into perfboard with the least amount of parts required would probably only cost you about $9 or less if you source the pieces carefully.  While an actual Arduino form factor makes a lot of sense when you’re using off-the-shelf shields, it’s not nearly as important when you’re building a very simple or completely custom project that you don’t intend to take apart.  And, when you’re talking about leaving a chunk of electronics in a project, it’s a lot easier to leave $9 in parts inside rather than a $30 Arduino board.

Here’s what I found to be the (near) least number of parts and (basically) the smallest configuration for the programming MintDuino:

The (almost) minimum you need to upload an Arduino sketch

The (almost) minimum you need to upload an Arduino sketch

This is the “almost” minimum since the configuration above includes (1) a red power indicator LED and a 220 Ohm resistor and (2) a red wire, another red LED, and another 220 Ohm resistor for running the “Blink” sketch.  Once you remove those parts, you could still upload a sketch to the Arduino – but it wouldn’t be able to do anything.  You’ll notice that this configuration doesn’t even include the usual reset button for the Arduino.4 It’s not pictured, but you’d also need a way to communicate with the Arduino, such as a USB cable plus FTDI Friend or FTDI cable.

Here’s what I found to be the (near) least number of parts and (basically) the smallest configuration for running a sketch on the MintDuino:

The (almost) minimum you need to run an Arduino sketch

The (almost) minimum you need to run an Arduino sketch

Again, I’m qualifying the statement with an “almost.”  This nearly minimum configuration above again includes a red wire, another red LED, and another 220 Ohm resistor for running the “Blink” sketch.  You could remove all of these parts and connect whatever else you wish the Arduino to do for you.  While the power LED indicator is useful to know that your project has power, I could see some situations where you wouldn’t want it – such as for a project that needs to work in the dark without drawing undue attention to itself.

Besides fiddling around yanking parts out of my MintDuino to see what would happen, I also found some interesting tidbits about building a minimum possible Arduino.  If your project is tight on space or you are tight on parts or budget, you might find some of the following useful:

I’m still very new to this whole Arduino thing, so if you notice something wrong here, please let me know so I can fix it.

My very next Arduino project is going to be something that fiddles with my television’s IR (infrared) control codes.  You can expect some definite wackiness soon…

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  1. Since I wanted to include a picture of the MintDuino inside and out, I couldn’t help putting a spin on this classic Groucho Marx quote. []
  2. I ended up using the Mintduino tin – and actually recycling some of its packaging into the project as well []
  3. What project am I referring to? Stay tuned… []
  4. I discuss this more below, but I don’t think you need the crystal and two capacitors for the “external clock” functions of the Arduino if all you’re doing is uploading a sketch. []

Arduino Adventures: What I learned building a MintDuino

A MintDuino

A MintDuino

My first real foray into tinkering with an Arduino began a few weeks ago with a MintDuino.  About two years ago I contemplated trying one out, but I never pulled the trigger.  This was due to a combination of decision paralysis, a very short attention span1 , and a plethora of other projects that were always vying for my2 attention.

Overall, I think this was a good place for me to start learning about Arduinos.3 The nifty thing about the assembly tutorial for the MintDuino is that it takes you slowly through the creation of an Arduino.  I learned a surprising amount from assembling this little breadboard Arduino – more so than I ever did by just making an LED blink on a regular Arduino Uno.

  • The first thing the tutorial does is show you how it converts the power from a 9 volt battery into the 5 volts that an Arduino would use.  I found this incredibly useful.  Even if I had stopped reading the tutorial at Step 7, I would have learned that with some capacitors and a “voltage regulator,” I could create a system for converting power from a 9 volt battery into something I could use in a different project.  Sure, I didn’t learn how these parts made that happen, but this was something I could put to use immediately, if I so chose.
  • The second thing the tutorial takes you through, at step 9, is adding a “crystal.”45  This wasn’t particularly useful to me – except that now I know how the Arduino is able to keep time.  While doing some ‘net research on what constitutes a bare-bones minimal Arduino, I discovered that it is possible to omit the crystal and two capacitors in favor of the chip’s internal clock.
  • The third thing I learned from this tutorial, at Step 12, is what appeared to be the bare minimum MintDuino setup required to run a program that was loaded onto the Arduino’s chip.6 Now, it’s possible to remove several more pieces and still have a working Arduino.  If you just had to have an Arduino with an absolute minimum of parts (I’ll get to why later) you could pull the red LED, the 220 Ohm resistor, the black wire going to the red LED.  The result would be a pretty minimal Arduino that didn’t have a status/power LED, but could blink a single green LED.  Remove the green LED, the red wire going to it, and the 220 Ohm resistor going to the green LED, and you have a really stripped down Arduino – that can’t do anything.  But, if you were to design your own Arduino project, you could build this minimalistic Arduino, add connections to whatever additional parts you needed, and solder it all together.
  • By the time I got to Step 17, I learned the connections to the ATmega328 necessary to program the chip with an Arduino program.7  This was interesting to me because it meant that any circuit that I wanted to design, but still have the capability of reprogramming at a later date, would have to have these connections.  However, it would probably easier to add a 28-pin socket or 28-pin ZIF socket to your project so you can remove the chip, reprogram it, and replace it without much fuss.  ((I mean, why add a bunch of wires you only need for reprogramming to a project when you can add a little socket?))

Overall, tinkering with a MintDuino taught me quite a lot about Arduinos.  Staring at an Arduino for the first time out of a box, it’s a little daunting.  There are a ton of little surface mount parts and pins and I had no idea where to start.  I had made an LED blink – but that didn’t seem to do much for me.

Having assembled a MintDuino, I already knew what a bunch of the parts already did – so I could focus on building on my knowledge from there. Having the breadboard handy meant it was easy to connect more wires and try out other sketches and configurations.  Lastly, I went back over my work from the first time I built the MintDuino and rewired it so that the little red, black and green wires didn’t have any slack.  This let me see better which wires when where – which meant I could concentrate on working with the other pins.

I mentioned earlier why I was interested in finding out the absolute minimum amount of parts necessary to operate an Arduino.  Well, more on this in the very next post…

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  1. Oh!  A squirrel! []
  2. Oooh!  A shiny! []
  3. I say “start” because my prior experience with Arduinos consisted of just putting shields on Arduinos and uploading sketches. []
  4. I don’t know why they call it a crystal – it just looks like a little bit of metal with two wires sticking out []
  5. I’m just kidding.  I’m guessing they’re using a quartz crystal – similar to quartz watches – as a timer/clock.  For those of you who aren’t familiar with quartz watches – they keep time by applying a little bit of electricity to a piece of quartz and counting the vibrations of the crystal. []
  6. The Arduino’s chip is called an ATmega328 []
  7. Or, in Arduino parlance, “sketch” []

Arduino Adventure Series – The Adventure Begins!

Arduinos, Arduinos, Arduinos... where to start?!

Arduinos, Arduinos, Arduinos… where to start?!

A few weeks ago I started fiddling with an Arduino in earnest.1 I’ve built things using Arduinos before, but each time all I did was slavishly follow a tutorial as it took me step by step through a process.

Just as a child memorizes the Pledge of Allegiance, committing to memory the right sounds in the right order, I had a grasp of the assembly – but not the underlying meaning.  Sure, I built a MakerBot Cupcake CNC (“Bender”), a MakerBot Thing-O-Matic (“Flexo”), an Egg-Bot, a Polargraph/PlotterBot, and an IoT Printer.  ((FYI, my MakerBot Replicator 1 is named “HedonismBot“))  However, I have only the dimmest understanding of how the things I did actually created the things I ended up building.

However, I want more – there are several ideas I would like to create using electronics.  One is a sonic screwdriver flashlight.  Another is device for … shall we say…2  interfering with television infrared codes.3

My goal for this series of posts4 is to document my triumphs and failures playing with an Arduino.  I think it’s time to get started on that next post now…

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  1. Photo courtesy of Arkadiusz Sikorski []
  2. Mu-ah-ha-ha!!! []
  3. Nope, not a TV-B-Gone []
  4. I know it’s ambitious to call a post the “first” post – but dammit, a man’s got to dream []