Touch sensitive led table

[cubera]

Hi I'm actually new to the forum and I'm not quite sure if this is the right spot or not.. But anyways im trying to build a circuit similar to the octolively kit created by a company called evilmadscience.

Here's the website:
http://cdn2.evilmadscience.com/KitInstrux/octolively/html/index2.html

Im wondering two things:
1. What do the infrared photoresistors do? as in how is it used?
2. What does the infrared led do? and how is it used?

Here's what I want to achieve:
A table top in which the leds get turned by either the motion of hands waving over the glasses or led lights that turn on as the hand is hovering over the glass.  Im planning to have the photo-resistors take in the serial values, and when someone hovers there hand over the photo-resistor the led light turns on, as the photo-resistor is used to detect the ambient light surrounding it. I'm not looking for a led rippling effect I just want something simple as leds turning on by either motion detecting or light detection.

Also is there a way to build something similar to this using photo resistors and leds? If so could anyone provide me with a pseudo code or just explain to me the theory of how this could work? If there are other methods of building something similar to this I would really love to hear your opinions!

I have something in mind but I have to wait until my photo-resistors arrive to put it in action and start coding. As of right now any help is appreciated! And if this is in the wrong spot please post it below and tell me where I should post this. 

[Riva]

Im wondering two things:
1. What do the infrared photoresistors do? as in how is it used?
2. What does the infrared led do? and how is it used?

The infrared led & phototransistors are used to do proximity detection.

Im planning to have the photo-resistors take in the serial values, and when someone hovers there hand over the photo-resistor the led light turns on

Where does the serial data come from?

I just want something simple as leds turning on by either motion detecting or light detection.

Light detection = easy. Motion detection is harder as you either need PIR sensors or some other form of machine motion detection that may be beyond arduino's capabilities.

Also is there a way to build something similar to this using photo resistors and leds?

Have a look here http://learn.adafruit.com/photocells

If there are other methods of building something similar to this I would really love to hear your opinions!

Might be worth looking at this http://www.thebox.myzen.co.uk/Workshop/LED_Sensing.html as you could use the LED as the light sensor.

[cubera]

Sorry for the late reply, but thanks alot for your input, i'v decided to do light detection method, but im wondering is there any way to do proximity detection with an arduino? could I use the same mechanics as the company that made the octolively kit and use both infrared photo resistors and infrared leds to get proximity sensing?

Im wondering two things:
1. What do the infrared photoresistors do? as in how is it used?
2. What does the infrared led do? and how is it used?

The infrared led & phototransistors are used to do proximity detection.

Im planning to have the photo-resistors take in the serial values, and when someone hovers there hand over the photo-resistor the led light turns on

Where does the serial data come from?

I just want something simple as leds turning on by either motion detecting or light detection.

Light detection = easy. Motion detection is harder as you either need PIR sensors or some other form of machine motion detection that may be beyond arduino's capabilities.

Also is there a way to build something similar to this using photo resistors and leds?

Have a look here http://learn.adafruit.com/photocells

If there are other methods of building something similar to this I would really love to hear your opinions!

Might be worth looking at this http://www.thebox.myzen.co.uk/Workshop/LED_Sensing.html as you could use the LED as the light sensor.

[Riva]

i'v decided to do light detection method, but im wondering is there any way to do proximity detection with an arduino? could I use the same mechanics as the company that made the octolively kit and use both infrared photo resistors and infrared leds to get proximity sensing?

A quick google will list several Arduino projects that do proximity detection. http://bildr.org/2011/03/various-proximity-sensors-arduino/ shows IR proximity. Depending on how big the table is / how many IR detectors you need you may need to use some external hardware to multiplex the analogue inputs. A possible problem with using regular photo-resistors (Light Dependant Resistors) is the table would light up as the room gets dark and this light could effect the LDR. The probable reason they used IR is it will work in the dark and is less effected by visible light.

[cubera]

MAN! i just noticed that right now! In the dark the photo-resistors become useless. Is there anything like infrared photo resistors or anything like that to capture some signature from objects or human hands? I know infrared leds can be seen on camera so could i use those to transmit a light to the object coming in contact, then use something else to capture the infrared light beaming on the object?

i'v decided to do light detection method, but im wondering is there any way to do proximity detection with an arduino? could I use the same mechanics as the company that made the octolively kit and use both infrared photo resistors and infrared leds to get proximity sensing?

A quick google will list several Arduino projects that do proximity detection. http://bildr.org/2011/03/various-proximity-sensors-arduino/ shows IR proximity. Depending on how big the table is / how many IR detectors you need you may need to use some external hardware to multiplex the analogue inputs. A possible problem with using regular photo-resistors (Light Dependant Resistors) is the table would light up as the room gets dark and this light could effect the LDR. The probable reason they used IR is it will work in the dark and is less effected by visible light.

[Riva]

Maybe something like this http://www.pololu.com/catalog/product/959 but get other views on this as I have not used IR proximity so cannot be sure they are really suitable.

[toxman]

i believe i'll make one of this....

[Riva]

i believe i'll make one of this....

I'm not sure if cubera made this. I have since seen a few examples here that actually use an LED as the light detector so if your using individual addressed LED's it may work. Grumpy Mike has done an article on this