Help for a complete beginner!

Forum 2005-2010 (read only) Hardware Interfacing
1

Hi all,

I am a complete beginner with this, Ive done a load of basic tutorials but other than that I have very little experience.

I am attempting to create a sort of prototype for an idea I have for an interactive wall surface. The surface will respond to degrees of proximity of people moving infront of it with a display of colour.

For the prototype I have an Arduino board and am attempting to use that as a method of collecting the information from the sensors (im not yet sure what the sensors should be).

With that information I want to create a real-time, dynamic animation (MAX MSP/Jitter?) which simulates the sort of patterns of colour which would be projected onto the wall surface.

The colour pattern will be a series of squares who's colour and intensity is directly related to the proximity of a person.

Of course this prototype will be a scaled-down example of the wall surface, and the effect can be demonstrated by simply moving your hand over the sensors on the Arduino Board

The two main questions I have are:

  1. What would be the best sensors to use for this? LDRs? How many? Any information on how to set this up on the Arduino would be great

  2. How to I interpret that info in order to create the visualization?

Any help is much appreciated, and I hope I have made some sort of sense!

Thanks

Rich

2

A search for arduino proximity sensor on google should get you started.
There are many different technologies that may be relevant, such as body heat detection (as used in alarm or lighting proximity detection), infra-red or ultrasonic distance detection, or body capacitance (as used in a Theremin for example).

Which one is best depends on how people will move within your installation and how you want it to react.

Have fun!

3

another important factor is distance, how far away / close do you need to sense a person ? and precision how accurate do you need the distance measurement to be ?

4

One of these might be what you are after - http://www.robotshop.ca/sharp-gp2y0a02yk-ir-range-sensor-1.html

5

There are a TON of options for what your trying to do. My advice is narrow it down a bit more. Figure out the distance of the people, how often they're going to be in front of the sensor, do you want to keep track of the people as they walk or just react at the points as they reach them (are the squares following individuals or are there squares all across the surface that will react as the person moves?), what level of accuracy do you want the sensors to report with, and how much are you wanting to spend?

This could go anywhere from a simple range finder, to an acoustics DSP system to machine vision. None of them "better" than the other unless they meet your conditions.

6

thanks for all your help guys, its much appreciated!

For this project in particular, Im not wanting the prototype to function on the same scale as the interactive wall surface, this will be much smaller and detect the movement of, say, someone's hand in front of it. Id say a range of sensitivity of between 0 and 20cm.

It will be used purely for demonstrative purposes, and wont actually be left to record movement over a long period of time.

I dont think the sensors need to be touch-sensitive as such in this case, probably only light or heat sensitive would do.

Imagine that the A,S,D,F,G keys on your keyboard are sensors instead of keys. They are linked to a visualization consisting of an grid of coloured squares on the screen (which are initially white when nothing is sensed). As you move your hand closer to the sensors the coloured squares on the screen react by becoming more vivid, depending on where your hand is. Say you then moved your hand in a line from A to G, a trail on the grid of squares would follow this movement. After few seconds the coloured squares would dissolve back to white.

I hope that's clear!

Thanks again for the help, im checking out those links now...

7

Oh and as for price, studenty sort of prices are most desirable!

maybe £50 max for everything? (not including the board)

8

maybe £50 max for everything? (not including the board)

Ouch!! Good luck with that!! :-/

9

Then something like this would probably do it:

You can hook it up to one af the analog inputs on Arduino.

10

If that sparkfun sensor is too expensive in the quantity you need, perhaps try and prototype something simple like 5 or 6 light sensors arranged behind a screen so that the approximate position of a hand could be detected by monitoring the light and shadow on the sensors.

Another approach is to use body capacitor sensors. Have a search to see if you can find a simple circuit, you would need 5 or 6 of them for your simulation

11

That infrared sensor looks like it could be a good option - thanks MikMo.

Ill also look into those options mem - thanks

Could someone tell me where the best place to buy online in the UK is? I need reasonably fast delivery and fear ordering from the US may take a while...

thanks

12

I order most of my items from the US (as they tend to be cheaper) and to be honest they take no longer than the UK suppliers most of the time.

13

So I think Im going to go for this sensor, as it offers the range I need:

I understand that I also need one of these to connect each sensor to my arduino board?

Will I need a breadboard to connect these to or do they go straight to the Arduino? I also presume there is no soldering involved??

Thanks!