Category Archives: The Rest Of You

Toilet Seat Activated Light

For this project I used the orientation sensor as my switch. I then attached the circuit to the toilet seat. When the seat goes up, the light turns off. When the seat goes down, the light turns on. The point being to remind people to put the seat down. The problem is that the light should be on when the seat is left up, as a reminder to toilet-goers to put it back down, but I don’t believe that can be accomplished without code.

Photo of circuit

In operation WITH MY FOOT!!!

Gas Leak Detector

I realized my apartment doesn’t have a smoke or carbon monoxide detector. So, I decided to make a DIY simple carbon monoxide detector.

The circuit is pretty simple. I connected a cheap gas (and alcohol) sensor to analog in. The LED lights up when the value of the analog in is higher than 400.

It wasn’t working first, but it turned out that the resistor had bad connection or broken. After I replaced the resistor, it started working.

The code looks like this.

int val=0;
int red=8;

void setup(){
  pinMode(red, OUTPUT);
void loop(){
  if (val >= 400){




Light detector

Have you ever found yourself too lazy to reach for the switch to turn on a lamp? Ever needed an indicator that the sun has already set? Or just wanted to check if your flashlight was on? Introducing a lamp that switches itself on when the light is low in its surroundings.

After thinking hard what could be a switch that doesn’t need hands to switch itself on or off, I have came across the phototransistors in my Arduino Starter Kit and had a “Eureka!” moment with them. They can detect the change in light and don’t require touch to switch on or off.

At least on paper. Due to the characteristic of the phototransistor, the switch only happens in total darkness and during exposure to direct light. But it can easily detect your flashlight if you are pointing at the sensor from point blank.

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Subway Grate Powered Switch- Eleni Giannopoulos

When I started thinking about hands free switches I might’ve taken it a bit too far and started thinking about people free switches. I guess realistically there’s no such thing: there’s always some sort of human component, in the construction or the operation. But still, I was thinking of a way to take the control out of my hands completely.

I took Urban Arts last semester and we talked a lot about the mechanisms of New York City,  and the different byproducts of the way it functions. One of those, that I pinpointed as a useful force for my switch, was te gust of warm air that comes up out of the subway grates when the trains go by. I thought I could use that physical force to close the circuit.

To do this I knew I needed a light material that the air would lift. I shaped a plastic bag into a small dome with tape and by tying it. I also stuck some aluminum foil on top of the bag to be a light conductor. This would be the first part of the switch. For the second part I built a cube type structure around the bag with cardboard, clay, some brads, and these one direction pencils  my roommate gave me as a gag gift that I never knew what to do with (and now its perfect ’cause technically electricity moves in one direction (!!!))

The bottom of the base has a hole to let in the subway air, and the top has another piece of foil, so that when the bag is blown upwards, it’s just the right height and both pieces of foil are pressed together. I also added some clay as weight so when the air stops the bag sinks back down and the circuit is open again (the bag was surprisingly structural and wouldn’t collapse by itself which is surprising for flimsy trash).

This was basically the switch. I tested it on the subway grate first and all the other people on Broadway were a little upset and confused that I was sitting on a grate with a weird trash cube. Then I actually hooked up the wires, connecting the power source and resistor to a wire that was connected to the aluminum on the bag, connecting the LED to the aluminum on top, and then running another wire back to ground. So everyone got even more upset and confused when I sat on the grate with a weird trash cube that lights up every time the train goes by.  I didn’t anticipate the strength of the draft, and I had to hold the whole thing down so it didn’t launch like a parachute but that’s fine and easily fixed. (Consequently I couldn’t also film it in action because I couldn’t find anyone to hang around the grate with me, but I had my roommates help me film a replica of the situation with a blowdryer.)



Hands-Free Switch- Kevin Zhang

For my circuit, I wanted to make a switch that could be activated with any part of the body, so I looked up how to make a touch sensor. As it turns out, Arduino has a library called Capacitative Sensor that is designed to do just that. The picture below shows my circuit.

Pins 2 and 6 are the sensor pins. They detect whether or not the wires connected to them are being touched. Since I actually did not have any aluminum foil or metal strips at home, I just used the wire as the touch sensors. If I had the materials, I would have attached aluminum foil squares to the wires. In any case, the LED turns on when both the sensors are touched. Of course, this sensor can be activated by touching with the hands, but it can also be activated by any part of the body including, yes indeed, the butt. Here is the code for the Arduino:

#include <CapacitiveSensor.h>

 * CapitiveSense Library Demo Sketch
 * Paul Badger 2008
 * Uses a high value resistor e.g. 10 megohm between send pin and receive pin
 * Resistor effects sensitivity, experiment with values, 50 kilohm - 50 megohm. Larger resistor values yield larger sensor values.
 * Receive pin is the sensor pin - try different amounts of foil/metal on this pin
 * Best results are obtained if sensor foil and wire is covered with an insulator such as paper or plastic sheet
 * Code edited for class by Kevin Zhang on 1/29/2017

// 1 megaohm resistor between pins 4 & 2, pin 2 is the sensor, which has a wire connected to it
CapacitiveSensor sensor1 = CapacitiveSensor(4,2);
CapacitiveSensor sensor2 = CapacitiveSensor(4,6);
boolean value = LOW;
boolean activated = false;

void setup() {

void loop() {
 digitalWrite(8, HIGH);

 long start = millis();
 long touch1 = sensor1.capacitiveSensor(30);
 long touch2 = sensor2.capacitiveSensor(30);

 if (touch1 > 99 && touch2 > 99) {
 if (!activated) {
 value = !value;
 activated = true;
 } else {
 activated = false;

 digitalWrite(13, value);

 // check on performance in milliseconds
 Serial.print(millis() - start);

 // tab character for debug window spacing

 // print sensor output 1

 // arbitrary delay to limit data to serial port 

The values touch1 and touch2 are the input from the sensors. When the sensors are not activated, they hang around the 0-20 range, but when touched they shoot up to the hundreds and sometimes the thousands. There are a lot of ways to use the touch sensor. An idea I had was to attach up to 9 sensors and have a key code to turn on the light!

Handless Circuit

We were assigned to create a circuit in which you don’t use your hand to flip the switch. I had a lot of difficulty deciding how I would go about doing that, but decided to try to attempt some sort of method using a floating piece of conductive material to complete a circuit. I thought about using washers, some sort of metal plate, or some sort of copper wire weave, but wasn’t sure how effective any of those methods would be. After doing a quick Google search for some conductive materials, I found I could use aluminum foil. After assembling all my components, I tried to actually put together the circuit.

I used the breadboard because I thought it would help me better visualize and organize the flow of electricity through the circuit. Using a resistor was confusing and I had difficulty trying calculate which sort of resistor I should use, and how to determine the function of the resistor. When asking a friend for her opinion, she thought that we were always advised to use the 1k resistor, so that’s the one I ultimately chose. When most of the circuit was set up, I tried figure out the “handless” part of the assignment.

Here, a test was conducted to see if tinfoil would be a reliable conductor for the electricity. It turns out the internet didn’t lie this time around.

In the ITP shop I found a small cup and some tape. The cup was small enough to act as a bit of a guide for the tinfoil, to make sure water poured from above wouldn’t force the tinfoil away from two pieces of exposed wire, which would complete the circuit. The tape was used to attach the wire to the cup, and position the wires to come into contact with the aluminum. When water is poured into the cup, the aluminum foil comes into contact with the wires, completing the circuit and making the LED light shine.

When putting the whole circuit together, I had some difficulty having the light shine. I tried to figure out what the issue was, maybe the positive end of the battery was attached to the black wire, maybe I needed the resistor to be in another place, maybe I had a defective battery. Testing the potential problems resulted with the same dark LED. I decided it could have been the voltage for the LED, I knew the green one I was using was 2 volts, changing to a red one allowed the light to shine dimly. When changing to a blue LED with 3 volts, it shone the way it had in class, I I realised this was the proper LED I should use with this battery and resistor. Finally, I was able to put together the circuit.

Ryan Chong Post #1 – Some Ideas.

I’m not really sure what to write here. I have thought of couple of ideas of how to have a switch that didn’t require hands. They probably exist somewhere out there, but my ideas are being able to have a switch that operates when there’s a vacuum vs in open air, kind of like a vacuum detector. Then there’s the idea of operating when there is water vapour where you blow into it, or kind of like a humidity detector, where it can be prevented from activated when it’s dry wind or something.

The video about Red Burns was really inspiring though, gave me a new drive to stay in the class.

Tea Time

I wanted to make a switch that would turn on the LED when I set my tea cup down, in other words a sort of two-piece coaster that will only touch and close the circuit when pressure is applied. I started by wrapping two cardboard circles in aluminium foil and attaching them to jumper wires. I then taped a piece of sponge to the middle of the bottom piece so that the two pieces will remain separated unless pressure is applied by a heavy object such as a cup.

Initially, I cut the sponge into a larger piece but it made the coaster very wobbly, and I didn’t want the cup to topple and spill and possibly set my apartment on fire. So I cut the sponge down to minimise wobbliness and to make the circuit more sensitive to pressure.

And here we are. Reviews from friends include “plsssssss hahahahaha”, “cute”, but also “dumb”.

Orientation Switch

For my circuit, I decided to use the tilt sensor included in the Arduino starter kit as my hands-free switch. The tilt sensor is a hollow cylinder with a metal ball inside that makes a connection across two leads when tilted in the proper direction. The switch is closed when the circuit is lying flat and opened when the circuit is tilted.

View post on

Switch on

View post on

Switch Off

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In Action

ASG 23/01 (kotomori)

DISCLAIMER: I am not an engineer/STEM person. I got a C in geometry if that’s any indicator and the only math I’m good at is calculus because I’m good at manipulating things.

The first thing I did was conceptualize how in the hell I was going to make a switch not directly set off by hands. My first idea was a windmill, then some type of water-pressure system (once again: not an engineer). After kicking myself for even thinking that water could work with electricity, I focused on the ‘pressure’ part and came up with the idea of a balance pressure switch. Then I drew a little schematic, and I went to building:

Problem no. 1: finding the sturdiest fulcrum.


I tried 3 different types of cylindrical fulcrums, and then settled on making my own triangular on out of some plastic from a false-eyelash container. Reduce, re-use, recycle. As for the actual balance “beam” if you will, I found aluminum foil to be the most accessible conductive material, so I made one with similar dimensions to a piece of 5 gum. Then I made little weight holders, also out of aluminum foil, and stuck them to the beam using nail polish because my glue dried up.

Problem no. 2: proper weight

Initially I used a foil ball to tip the switch, but it was not heavy enough.  Eventually I tried a pearl earring and everything went swimmingly.

Here are some bits from my snapchat. As you can tell, I was excited.

IMG_4283.mp4 IMG_4284.mp4 IMG_4285.mp4

Assignment 1

First I decided to build a simple motor with a battery, magnet, and copper wire. The motor causes the copper wire to spin around. I used this to complete the circuit, and cause the light to turn on. The circuit was really simple and just used a LED light, two AA batteries( they are 1.5V each), and the motor. I used the bread board to make everything in series. Taped two batteries together since they are in series and are both facing the same way the voltage builds up instead of cancelling out. And since the source voltage only adds up to 3V there is no need for a resistor. Then the rest is connected in series and then I left a break in the circuit to be closed when the motor spun the wire around to fill the gap. The motor is a simple physics trick and works because an electromagnetic field is produced, and the wire is also carrying a charge and so a force is induced and pushes the wire around in a circle. Ideally I would have made it so the motor would just brush up against the wires at the same moment so the light would flicker on and off by itself as the motor continued to spin the wire around, but it was a bit difficult as the wire was difficult to balance on the battery and to space the connecting wires perfectly.


This is how the motor works.

This is how I set up the circuit.

This is my project in action.

Assignment- Yip- from Jan 23

I started the assignment by creating a simple circuit with 9V battery and LED on a breadboard. I am using breadboard just to make things clear to me:

Then I added a switch with a piece of aluminum foil. The setup is pretty straight forward: I used some materials that I could find from my apartment (cardboard, toothpicks, origami paper, aluminum foil) to hang the small piece of aluminum foil, so that the circuit would be connected when I blow the foil.

The only slightly tricky thing for this set up is to find the best height for the foil to hang, since the foil is thin and flexible.  After a couple trials, the best height is where the edge of the foil could touch the alligator clips when one blow the foil.

Here is the result: