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Wk1: Getting Into Physical Computing

Reading Part

The required reading part for the first class gives me a thorough brushup on the basics of electronics due to my electrical engineering background. Yet it has been about two years or so since last time I played with circuits and electronic components, so not all of the content is quite familiar to me. I will just markdown things that I need to take a second look at here.

– Electricity: the Basics

— Terminology
actuator: convert electrical energy into other forms
transduction: transfer one energy into another
transducer: device to do transduction

— Components
conductor & insulator: A piece of dry wood is an insulator, yet a piece of soaked wood is a conductor. The human body is a conductor or insulator? – poor conductor, so an insulator

Switch: Dual-pole switch: I have only seen it on schematic diagrams, so I am not sure how it works in a real circuit with its multiple leads. (I should buy one to try.)

transistor & relay: They are both electrical switching devices (but what is the difference?) Relay includes a coil wire and a switch, turn the switch on/off with magmatic field, normally rely allows much larger current to go through, the coil wire is the actual part connected into the circuit

resistor:
variable resistor: eg. FSR
Potentiometer: linear and rotary type
Light-dependent resistor: passive component, decrease resistance with respect to receiving luminosity on the component’s sensitive surface (Wikipedia is my good friend)
Thermistor: how? resistance increase as temperature goes up? Or go the other way around?
Photoresists: how?
Flex sensor: how?
Piezoelectric device: what?

– Understanding DC Power Supplies

I tested the DC volts using a multimeter by connecting two probes. 

DC Voltage with proper probes connection
w/ proper probes connection

DC Voltage with reverse probes connection
w/ reverse probes connection

 

Lab Part

– Knowing your components

The first assignment assigned in this part is to help us identify each electronic component with some basic introduction. This is like a data sheet that I will come back and check pretty often. I just markdown something that I hardly used before here.

voltage regulator: convert the voltage from one level to another. (input: left leg, ground: middle leg, output: right leg) 

– Setting up breadboard &
– Electronics and using a Multimeter

This was the first time that I used the voltage regulator to convert voltage from DC 12v to 5v. I tested its function with a multimeter by reading the voltage from its output leg. I also connected it to a LED to check whether the LED illuminates.

regulator7805 turns DC12v to 5V
regulator7805 turns DC12v to 5V and illuminate LED

In this part, I played with the LEDs both in series and parallel.

3 LEDs in parallel do not illuminate
LEDs do not illuminate cause the current flow through is too small
3 LEDs in series illuminate
LEDs illuminate because the current flow through them is large enough.

 

 

 

 

 

 

 

– Switch

I used a button switch to turn on/off of the LED, which gave me a brushup on how switch worked in a circuit. 

 

– My creative switch design: Soap Bubble Switch 

Idea:
When it comes to making a switch, the first thing that popped up in my head is to find some conductive materials. The idea of using a soap bubble as the conductive media to operate the switch hit me when I was washing hands with liquid soap. Is the soap bubble conductive? With some research online, I confirmed that it is conductive. Once I decided the most essential material, I began to design my switch. I expected the process of turning the switch on and off be entertaining and interactive, so I believe blowing bubbles to let bubbles land across two conductive pad can be a good choice. 

Prototype:
I put the copper tape on both sides of a plastic pad and remain the middle part still plastic, which allows the soap bubble to be the conductive bridge. The entire circuit is quite similar to the one with a common button switch plugged in.

conductive pad
conductive pad
soap_bubble_switch_prototype_v2
soap bubble switch prototype

 

 

 

 

 

Demo:

I demo it in two versions – light one and dim one because the brightness of the LED is not obvious when the room light is on. I fast forward both videos because it took me about 1 minute to blow a bubble right landing across two conductive areas. Maybe I am not good at blowing bubbles or my recipe for homemade soap water is not at the magic ratio. 

 

 

Future Work:
If I can transfer the current conductive pad to a chessboard-like conductive pad, it will be much more entertaining and effortless to blew bubbles and light LEDs up. 

 

Reflections on “ fallacy of invisible interfaces” by Timo Arnall

I think the points that the author makes in this article towards the fancy concept “invisible design” are quite convincing. I think when people consider “invisible”, they expect an everywhere AI to provide anything they are thinking or want to do at that moment without any further physical instructions. I admit that some products like auto-vehicle have already been on this track, but excluding this intelligent part, what we still want is a response before action commits. We want to see (from the customer side) the system or product is under control and performs follows the instruction. That’s maybe a reason that I believe Tesla keeps a huge touch screen in his car even though the voice is enough to control and give the response.

I’d like to mention one of my favorite artworks “Hi, a real human interface”, a short display in the Museum of Modern Art (MoMA). Inside a small screened box, a flesh-and-blood person disintegrated three representations of abstract computations (emailing, loading and updating) with tangible objects and movements. This work amazed me that these subtly designed interactions could facilitate mutual adaption and information transmission between technology and us in a way that we barely perceive its existence in our daily life. This is the kind of invisibility that I think should be hailed for. Creating an understandable technology and design and applying to form people’s habit unconsciously, then the gap between interpretation and application becomes invisible.

 

Reflections on “A Brief Rant on the Future of Interaction Design” by Bret Victor

I wholeheartedly agree with Bret’s argument that “hands are our feature”. The dexterity of our hands and bodies is a great asset for us to take into account when creating interactive technology.

The intuitiveness to lose the lid of a jar, to flip pages of a book, to hold the plates and etc. can be a great start for transferring that intuitiveness to an interface or a technology. For example, many digital readers now provide the page-flipping effect to allows people to go forward or backward using a finger to slide from any corner to center. Comparing to the older version – a click button with an arrow on it, we can feel that this gesture is quite natural and intuitive.