Spark | The Research Part 1

Though exciting, finding the right way to tackle this project has been tough! But I’m taking it in chunks.

As always, Trello is my organization go to! This is my Spark board, with the in-the-works outline, the next steps, the animation to-dos, and what I’ve done so far. (…I promise I actually have done more than that.)

screenshot

As it goes, for a project like this there is always things to learn and research to be done! And especially for this one, since there are things that I will be covering in the video/animation that I myself don’t fully understand. 😀

Here’s some of the basic information I’ve learned so far.

The word electricity is used in so many different ways that I am going to avoid using it as much as possible, though that is the thing I will be attempting to teach. Electricity has many connotations, many different meanings, and is all around confusing when you use it repeatedly to describe contrasting ideas.

A useful link: http://amasci.com/miscon/whyhard2.html

I assume that the reader understands the basic model of an atom and has a foundation of  Work and Energy concepts. This is the generic highschool definition of voltage, which is about halfway accurate. I’m saving the calculus definition for another blog post by itself.

Disclaimer: Though I mention and talk about V = IR, I will not cover resistance.


Charge. In the physics world, Charge is a physical property of matter, similar to how plants have different chemical properties. Particles and matter have the charge property, like the lavender plant has the calming property*, or how matter can also have properties such as mass, temperature, and more.

Of course plants are on a much larger scale than the particles in question, but the analogy still stands.

Charge is measured in Coulombs. Protons have a positive charge of +1.60217662 x 10^-19 Coulombs, electrons have a negative charge of -1.60217662 x 10^-19 Coulombs. That is an extremely small number! (0.000000000000000000160217662, to be visually exact.)

Since the charge of 1 electron is just a fraction of 1 Coulomb, how many electrons would it take to equal 1 Coulomb total?

1 ÷ 1.60217662 x 10^-19 Coulombs6,241,509,000,000,000,000,000,000 electrons! (6.241509 x 10^18)

Protons and electrons are so tiny that it takes trillions of them to equal 1 Coulomb of measurement, as seen above.

In the topic of electricity, we often hear of terms such as current, voltage, and resistance. All three of these terms make up a very important equation we call Ohm’s Law.

Ohm’s Law looks like this: V = I * R

Where V stands for Voltage, I stands for Current, and R stands for Resistance.

For you non-equational folk, have no fear. I will do my best to explain without mathematics.

Because we know about charge, we can start using our knowledge to flesh out more of these concepts. Lets start with I, Current.

Current is the measurement of how many Coulombs (or charge) is running past a certain point every second. When we look at the unit of Current, it is:

coulomb-per-sec

Remember how many electrons are in one coulomb? If we had a Current that was 1 Coulomb per Second (1C/s). That would equal 6.241509 x 10^18 Electrons / Second (I just replace 1 Coulomb with the amount of electrons it is equal to), which is a lot of charge! 2 Coulombs per second would double that electron amount, which means more charge is flowing.

Current is measured in Amperes, so we can replace current in the unit equation with:

 

1 Ampere = 1 Coulomb / Second

 

This also means that Amperes is proportional to Coulombs, as long as that 1 second stays consistent. To translate, that means that 2 Amperes = 2 Coulombs / Second, or 4 Amperes = 4 Coulombs / Second.

 

Question time! If we have 20 Amperes of current, how many Coulombs would that be in a second? How many electrons would that be?

 

Amperes is always equal to Coulomb / Second, so if we have 20 Amperes, we have 20 Coulombs / Second.

 

1 Coulomb is equivalent to 6.241509 x 10^18 electrons, so 20 Coulombs would be equal to:

coulomb-conversion

20 Coulombs x 6.241509 x 10^18 electrons ≅ 1.2483018 x 10^20 electrons!

Let’s make sure we remember what we’ve covered so far.

Charge is a property of matter, and it’s measured in Coulombs. 1 Coulomb is equal to a lot of electrons.

Current is the amount of charge moving past a certain point each second, measured in Amperes.

Now, to understand what Voltage really is, we need to examine more about the side effects of charge.

Each individual proton and electron produces an electric field. These electric fields correspond to it’s charge, so if it is a proton (or a positively charged particle), the electric field is positive. If it is an electron (or a negatively charged particle), the electric field is negative.

electron repel

See how these electron’s electric fields surround them, and repel each other? That mass of blue in the middle shows they can’t grow any closer. The force lines (with arrows) show where the electrons will go if the two are pushed any closer.

Same with these protons:

proton repel

Like charges repel. Because of the electric fields around them, they cannot grow any closer. Therefore, their force is pointed away in the other direction.

But if you have a proton and an electron:

electron proton attract

Opposites attract…do you see how the forces of the electric fields are drawn towards each other? They will get closer and closer until the +1.60217662 x 10^-19 and -1.60217662 x 10^-19 charges cancel each other out.

An electric field is like a bubble that exerts a force on other charges to attract or repel them.

If we had a stationary charge, a proton, like this one:

stationary proton

And we added another proton into the mix, what would happen to it, if this one (above) stayed stationary?

proton-repel

The added proton, wherever placed, would be repelled in the direction the arrows were pointing, because the protons repel each other.

See how the added proton is forced towards the stationary one, but is repelled because the electric fields can only get so close?

proton-repel

(pardon my GIF making…it’s the first one I ever tried!)

If we kept the original proton stationary and added an electron, they would accelerate towards each other due to the attractive force of their fields.

These electric fields play a huge part in explaining what Voltage is.

Electric fields, as I said earlier, exert a force on other charged particles. This force is measured in Newtons. These forces can react in three different ways: repelling forces that can be overcome (a proton moving over a repelling group of like charges), attractive forces will come together (proton + electron), and repelling forces that are too strong are pushed away (simply repelling).

The force needed to overcome moving past a group of repelling charges is called instantaneous electric potential. Instantaneous just implies the electric potential at one super-specific point in time. Instantaneous electric potential has a unit of:

joule-per-coulomb

If you remember in chemistry and physics, A Newton*meter is the unit for a Joule. This means we can simplify Nm/C to simply be J/C. But what does that actually represent?

joule-per-coulomb

A Joule is representative of energy. Energy is, by definition, the ability to do work. Work, scientifically defined, is exerting a force on an object to move it over a distance. A Joule, then,  is a measurement of the amount of energy it takes to accomplish exerting a variable force on an object to move it over a distance.

work-per-coulomb

Taking this definition, we can define what instantaneous electric potential is ourselves.

Instantaneous electric potential is the amount of Joules–the energy to move charges over a distance–per Coulomb of charge–that huge number of electrons–over a distance (this distance is often the opposite force exerted by the electric fields the new charge must overcome).

So, if we have 1 Joule of energy (the ability to exert a force on the charges to move them), and with it we move 1 Coulomb of charge (6.241509 x 10^18 electrons!), we have the equivalent of 1 Volt.

Keep in mind, this is only instantaneous electric potential (instantaneous Voltage), and charges are moving all the time! So this isn’t wholly useful, yet.

Voltage is accurately described as electric potential difference, and this is only slightly different from instantaneous voltage.

If we have a group of charges:

group-o-electron

And little Mr. Electron wants to get past them:

group-o-electron2

The force he needs to get around these guys at the beginning point (lets call it point A):

group-o-electron3

Is much larger than the force he needs to move once he’s gotten past them:

group-o-electron4

The electric potential difference of this situation is the Final electric potential (at Point B) minus the initial electric potential (at point A).

If you remember from algebra, subtracting the initial value from the final value gives us the difference. And this, my friends, is what Voltage is: electric potential difference. The difference between the initial amount of force per charge to move it over a distance, subtracted from the final amount of force per charge to move it over a distance.

Take this 3V battery. The top part of the battery labeled (+) is a positively charged plate of metal. The bottom part of the battery labeled (-) is a negatively charged plate of metal. When you connect the two, the opposite charges are attracted to each other, and the charged particles move because of that attractive force.

battery-circuit

Because this battery is 3 Volts, that is the amount of Joules per Coulomb needed to move the protons and electrons through this circuit. (3 J / 1 C = 3V) There are no obstructions for the charges to overcome, so the current (charge per second!) is constant.

Another real world example can be had with a common circuit component: Capacitors!

Capacitors are cool little nuggets. To put it simply, capacitors store charge. They have two metal plates on the inside, and the plates are separated by an insulator (material that does not conduct charge).

One of the leads is connected to the electron flow, and the other is connected to the proton flow. The metal plates begin to collect charge, but the charge can never meet in the middle due to the insulator. Therefore, a ton of positive and negative charge is built up on each plate, creating one massive electric field equal to the net charge of each individual electric field.

capacitor diagram

This electric field becomes an obstruction for charge to go past, which adds to the difference in electric potential magnitude. More Joules are needed to move the same number of Coulombs past the big electric field, which means a higher voltage is needed.

capacitor diagram2

Voltage is an extremely confusing subject if you don’t have a good understanding of the foundational principles of charge, energy, and work. But with a little thinking, it’s an incredible subject to be able to understand.

{thallia}

P.S. There will be a follow up post sometime soon with a visual on the calculus definition of voltage.

* disclaimer: there is a difference between chemical and physical properties, but the idea of a object or particle sporting a property is still the same.

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Binary Watch | Complete

5 months ago, I’d never designed a project from scratch. 5 months later, I’ve learned to design a PCB from a schematic, manufacture it, use a barebones microcontroller, 3D model with fusion360, write code that interacts with hardware, and much more. This was a crazy fun project!

<insert fanfare here>

Debugging the PCB was easier than I thought, I realized I was pressing the wrong buttons, therefore the code was running but it wasn’t displaying. You would think the designer of the device would know what buttons to press, right? Haha.

Gector (from UTW) bought a 3D printer of his own, so I revamped my 3D-modeled case design and sent it to him to print. img_6081

Nice and shiny and black. :))

img_6082

Looks preeetty slick!

forimg_6083

The PCB fits really well, too.

I deem this project officially done, from a designing standpoint! Everything after this will be upgrades, which I will work on when I have the time. With college in the very near future and working 2 jobs, my time will be pretty divvied up between work and family.

But! I have a list of upgrades and things to do next for this, so my mind isn’t taking a rest.

For the next board and case revision, I want to upgrade:

  • Power – The charging and power circuit needs to be on the board itself. That way I can charge it and not have to worry about buying a bunch of LiPo batteries over and over.
  • Experimenting with new power – I want to try powering this thing from a coin cell again. I have 2 other boards with this design, so I’m going to solder them together, but with different resistor types on the LEDs to see how much current the LEDs and microcontroller are drawing. That way I can estimate what the best resistor value is for brightness + mAh value of battery to get.
  • The 3D case is cool with the PCB exposed, but it ain’t cool because it’s exposed to the weather and other wet and sticky things. Therefore I must cover it up. The lid for case I design next will likely be screwed on, 1) for easier access and 2) for better security of the PCB. Depending on how secure I want it, I may add some kind of sealant. We’ll see…
  • 3D case – If I add a charging port, it’ll need a hole for the plug.
  • Through-hole LEDs – if the PCB is to be covered by the case, SMD LEDs aren’t going to shine through very well. I have some cool cylindrical blue LEDs that should work, so I’ll have to design the case cover to sit around/on top of them, which requires a new PCB design entirely.
  • With the PCB case covering the top, I’ll need to either add holes for the pushbuttons or design a way to put them on the sides of the case.
  • Watch strap – I’m planning on weaving some leather cord in a celtic knot fashion, or maybe some cool braided thing. I’ve been looking at some chunkier weaves on Pinterest, but I haven’t found the right one yet.
  • With the new case top, I may make it thicker and engrave some cool circuit-looking designs around the LEDs poking through and paint the engravings an electric blue color. Electric blue is a great idea.

And there you have it. This project is finished, and just getting started at the same time!

As for mini updates on other projects: I’m still saving up to replace the hard drive in my dell server (the old one croaked on me), and Spark is still very much in the works. Spark has some script work and content work to be done, but it will be updated soon 🙂

Onward, hackers!

{thallia}

 

Project Hype: Spark

So far, I have completed all of the goals I wanted to get done before college. This is huge! And now I’m bored…

Aside from debugging my binary watch’s PCB of course, but that’s minor and doesn’t take a ton of intellectually-stimulating brain thinking.

In the past month, I have invested more into my drawing and art-ing skills. I’ve always loved to draw, but just drawing scenery and characters and chibis have never really filled the gap I wanted it to. I love drawing and the results are always super fun, but I’ve never known what to actually do with what I produce.

Then…I had a spark.

What if I combined my art and creativity with technology and physics?

Thus was born Spark, an animation project to bring physics concepts to life. For this animation, I’ll be focusing on electricity/voltage, V=IR, electrostatic forces, and electromagnetic fields.

I have had a brief history of animation, starting when I was the wee age of twelve. I was fascinated with animation companies and how they produced movies. I would buy the art books of my favorite movies to see the concept art, storyboards, character design, and more. img_6006

(my collection of art books!) And yes, I have thoroughly inspected each and every one of these. I would pour over them for hours. I still do, sometimes!

Back to the point: I love animation. The process, the execution, the art. Gector lent me a laptop a while ago with Krita on it (Krita is an art and animation software), so I got my first taste of animation before the computer deleted my files .-.

But all hope is not lost! My grandma surprised me a week ago and bought me a Huion H610Pro tablet, which was beyond wonderful and I can’t be more thankful that she did that for me.

img_5970.jpg

img_5971.jpg

Isn’t it pretty?

I did some configuration on Linux following this guide: https://askubuntu.com/questions/500141/huion-h610-tablet#854842

img_5972

And Huion was easily recognized by my laptop! 😀 It’s seriously like drawing on butter. I love it.

So far, I created a basic script/timeline of how the animation will run, and to do that I’m researching my brain off to learn deeper and deeper about the things I’m explaining.

It is likely I won’t get it done super fast right now since I have a lot of schoolwork and work piling on me, but I’m doing my best to keep up with the speed my brain is running at on this project.

I hope you all will be as excited for the next update as I am!

{thallia}

PCB 95% Complete | Binary Watch

A little under a month ago, my PCBs arrived! It has been a hilariously long wait to get everything else up to par.

My GitHub repo is a little more updated every now and then before I write posts, if you want to follow along as I finish up: https://github.com/thallia/BinaryWatch

The binary watch came in the cutest purple package:

img_5899img_5898

And here’s the final product!!img_5897

Isn’t it gorgeous? I love the purple color.

I went immediately into soldering with the parts I had (which of course, took an extra week to arrive because of weather.)

img_5906

I forgot how tedious SMD/T soldering is.
Finally, I had all the parts soldered except for my lovely ATMega328P-AU.

img_5936

It took me forever to get a programmer for that thing. First I tried soldering wires to it, which was a bad idea.

Next, I tried ordering a cheap board from this place called Schmartboard. They had really good pricing but…img_5935

The place for the TQFP was wayyyyy too small. Oh well. I got a free pair of headphones out of it, so who am I to complain?

I finally got a paycheck where I could order one of these babies:

img_5990.jpg

And lemme tell ya. It was worth the $3.99 shipping. Not only was it super sleek and easy to solder the headers onto, but it worked ON THE FIRST TRY.

img_5991

That doesn’t usually happen, so I was extremely ecstatic.

img_5992

With some handy dandy wires I got the chip programmed, soldered onto the board, and I was finished.

But….the circuit doesn’t work on the PCB. So I now get to go through the delights of debugging a PCB, which sounds nightmare inducing and fun at the same time. We’ll see! XD But either way, this project is literally 99.9% done! I’m so excited.

In my next post, I’ll announce my newest project, the hardware and software I’m using, and what I’ve been learning to complete it in this post-absence of an Aprilish-May.

{thallia}

Final code, schematic, and PCB | binary watch

Last we saw, I got the binary watch code working with the 32.768kHz clock and fuse bytes (aside from the buttons!

The final code is out, I made the decision to keep the buttons simple and have them work only when the ATmega is awake. It’s much easier to let it happen that way than to use interrupts when the microcontroller is sleeping/waking up every second.

You can see my final code here:

https://github.com/thallia/BinaryWatch/blob/master/src/bwatch-clk.cpp

The display button is checked every time the ATmega wakes up, and if it’s pressed, it’ll display the time as long as the display button is held down.

Figuring out a way to stop the sleeping for 10 seconds would take a lot of workarounds and a lot of errors that I don’t have time to figure out right now, and I’m actually kind of liking the blinking display, too. Makes it feel more like a clock 🙂

As for the schematic, the final one looks like this!

screenshot.png

 

I moved some of the GPIO pins around for the buttons, added VCC and GND to everything, and added a JST connector. I decided it would be best to power this thing through a bigger power supply with easier access, so I bought a LiPo and added the JST connector to the schematic.

Routing the PCB was super easy with eagleCAD:

screenshot.png

And that’s the final board design! It’s super compact, so it should be able to fit on my wrist. The final dimensions were 37.0 mm x 43.4 mm. (I have a tiny wrist.)

I ordered the PCB through OshPark, I super highly recommend their services. They accept EagleCAD board files directly, so you don’t have to generate a bunch of gerber files, and keep you up to date on where your PCB is at at all times. I’ve gotten emails that my PCB has been through paneling and fabrication so far, and they should receive it back by mid-April.

The prices for the PCBs weren’t bad either. For 3 copies of mine it turned out to be a decent $12.75.

The parts (LEDs, caps, SMD parts, etc) should be here in a couple days…and I can’t wait.

Since I added a LiPo battery to the design, I now need to make a 3D printed case for the watch to hold it all. I’ll be using Fusion360 for that, so stay tuned!

{thallia}