Sunday, February 24, 2008

Sensors and Time

I chose a photocell for visualizing a sensor because I have never used it. The circuit was simple but it was not easy to connect arduino and processing. So I started with a really simple code and made them talk to each other first then kept developing them based on the code from the sensor wiki. After I did it, the photocell was giving pretty stable values as the amount of light.

Sensors and Time_Arduino code

int photocellPin = 0;
int value = 0;

void setup() {



void loop() {

value = analogRead(0)/2;


Sansors and Time

Version 1.

Processing Code for version 1.

Version 2.

Processing Code for version 2.

Version 3.

Processing Code for version 3.

Sunday, February 10, 2008

Sensor Walk

  • Heating system
    temperature sensor or thermometer outside of windows of my room to control the heater. - On a really cold day, heater is stronger.
  • Fire alarm - smoke sensor
  • Elevator
    weight sensor (scale?)– when the elevator gets overweight, it makes warning sounds.
    Cf. Escalators at the subway station – There are two ways escalator: going up and going down. So if you enter to opposite way, it would warn. And if the escalator is empty, it will stop.
  • ATM
    touch screen – it might be a basic question, how does it work?
  • Bookstore –barcode reader
  • Auto flushed toilets in a public bathroom – IR sensor
  • Auto sinks in a public bathroom – IR sensor
  • Security sensor bars at the store – magnetic sensor(?)
  • Automatic doors at the grocery store– IR sensor
  • Barcode scanner - Barcode
  • Conveyor belt
    IR sensor(?) - this belt looks like moving automatically. When there is some stuff at the edge of the belt, it stops and in the same situation but suff is far from the edge of the belt, it starts moving.
  • Iron
    temperature sensor – the little light on the top of the iron is turned on when it is heated
  • Nintendo DS
    touch screen / thermometer for the blowing option.

  • Night light – light sensor – When the room is bright, it is dimmed but when the room is dark it is getting brighter.

(Can timers be sensors? If they can,)

  • Auto turning off system of my camera - timer
  • Sleeping function of my lap-top - timer
  • Alarm clock - timer
    Cf. Speaking of an alarm clock, one of my friends have funny alarm clock. When it is ringing, to stop it you should make a sound like a voice or clapping instead of hitting a button.

  • People – I sensed people, and they did also.
    I have been thinking about the humans as sensors. When I called my mother she notices my mood, whether I have good news or I am tired just hearing my voice and its tone. At this point I want to talk more about sensing emotions than the five senses such as sight, smell, hearing, touch and taste. Sensing emotions could be related to intuition which is called our sixth sense. We can detect people’s feeling easily even unintentionally and react following what we detect. Sometimes it is wrong but I grantee, over 90 percent, it is right. We have such a good sensor. I can’t stop thinking about an emotion sensor. Is there a sensor that detects emotions except humans? If there is no sensor like it, how could I make it?

Tuesday, February 5, 2008

This one is really good. Actually I saw this company somewhere in Tom's new book, making things talk. It sells accelerometers, touch sensors, temperature, humidity and pressure sensors. And for me the most interesting sensors are light sensor and color sensor. Also this company provides good sources and descriptions for each sensor like codes of datasheets.

I was surprised when I visited this site because it is Korean site. But you can choose English. Sewori mainly makes ultrasonic sensors and image sensors. I think this site is not fancy at all but it is not complicated to search products so you can see the essential information about the products.

This site offers not only electronics but almost everything. But if you search ‘sensors’ in general, you can see various kinds of sensors such as IR, magnetic, vibration, current, optical, , humidity, gas sensors etc.

This company mainly makes temperature sensors.

Gemssensors makes liquid level sensors, many types of level sensors and also temperature sensors.

They offer many types of position sensors such as rotary position sensors, LVDT position sensors and so on.