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New ( offline )
Posts: 6
Posted: 2012-04-10 13:07 
Hello all,

I have been looking through everything I can, but still need a bit of help :) Sorry for the simple questions you will see below, but I feel overwhelmed at the moment...

Summary: I am going to build a VERY simple lighting system that will require low power (i.e., Typical batteries, if possible) to run for long periods of time. The system will essentially be a lighting system based upon proximity which will require a proximity sensor which will trigger the lights (LED type) based upon the logic I have set.

What I need:

* Low power Microcontroller, Board, and software to program

* Prox sensor which can detect an 'intrusion' quickly and even if it only passes within a sub-second time period (possibly 2 that would 'intersect' to be sure to catch the 'intrusion')

* Switch to power board to keep power off when not in use

* LED Lighting to be powered by board

Programming: Windows-based, if possible. I program in Basic, .NET, php, and very limited other languages. I can pick up any language, though, but would prefer a structured language.



Man, I hope someone can help me :) I am gong to keep looking around, though! It IS fun just doing that :)


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Admin ( offline )
Posts: 3728
Posted: 2012-04-10 13:59 
Most microcontrollers can measure microseconds - so you can choose almost any in the microcontroller category. Next, you need a distance sensor - choose one based on the distance you need (infrared is faster than ultrasonic). We have a range of small LEDs; check the current rating - the lower the better in your application. You can easily put a switch between the battery and the microcontroller to turn it off. To run for long periods, find a high capacity battery (the higher the better) operating at the microcontroller's nominal voltage. If you're new to the field, try Arduino, a Sharp IR sensor and a LED with breakout board. If you have any other specifications (size, cost etc), we can help you narrow the search.

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New ( offline )
Posts: 6
Posted: 2012-04-10 14:22 
ok, so here is what I was thinking:

Microcontroller: Arduino Uno USB Microcontroller Rev 3, RB-Ard-34

Sensor: DFRobot Adjustable Infrared Sensor Switch, RB-Dfr-49 OR Sharp GP2D120 IR Range Sensor - 4 to 30 cm, RB-Dem-03
(I like the simplicity of digital feedback. I'm not sure about the 'bright light' that it mentions, though, as the sensor would be used at night-time only)

LED and breakout board - I am lost :(


Here is more information that might help: Firstly, I am a newbie, but an electrical engineer. I have worked with microcontrollers, but it was a LONG time ago (1995, to be exact) and I forgot most of it :(

The intrusion detection will occur at night. I would prefer a 'line of sight' instead of a reflective detector, but not a huge deal I don't think... this WILL be in a semi-enclosed area, though, so I worry about reflective not being the correct application here. Think of this as a mouse hole (about 8" across) inside a box and a mouse moving quickly in. I need to detect that 'one-shot' and then code the LED actions based upon that intrusion.

The Lighting will be flashing a series of lights in a specific manner.. similar to what you might see in a new toy with the vibration sensor... I want low-intensity LED lights as this will be at night and I don't want super-bright. The code will do this: Flash the lights in a specific pattern. AND, randomly, flash in a different pattern.


I hope that makes more sense :) You have gotten me on my way, though. I had the controller picked, so you helped me validate that decision and had the detection picked as well, but added the Sharp up there just in case I am wrong (now I have reservations on the type of detection, though).


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Posted: 2012-04-10 15:14 
The best ways to detect a physical object are with a button / force / IR / ultrasonic / laser. If the distance can vary, then an IR sensor is best. Use two if the dimensions / location of the object may differ. If you are planning to use multiple LEDs, would the Rainbow LED Ring be of interest? If not, then you only need small LEDs <40mA like RB-Dfr-102 connected to the Arduino IO directly.

_________________
Coleman Benson

RobotShop inc.
Putting Robotics at your service!™
www.robotshop.com

Lynxmotion
Imagine it. Build it. Control it.™
http://www.Lynxmotion.com


New ( offline )
Posts: 6
Posted: 2012-04-10 15:34 
ok, makes sense on the detection stuff.

As far as the Rainbow LED Ring... looks nice, but I will be placing the LED's in specific locations as well :( If it is possible to cable them elsewhere besides on the ring, that may be ok, but likely would be better to output directly from the board to the LED otherwise. The Arduino I selected only has 5 PWM outputs, so I may have to look for others.


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Posts: 3728
Posted: 2012-04-10 16:12 
Certain LEDs need PWM to control brightness, while others are fixed and only need a digital pin.

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RobotShop inc.
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Lynxmotion
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New ( offline )
Posts: 6
Posted: 2012-04-10 16:16 
Yes, sorry I didn't elaborate :) I felt that the RGB LEDs would be better suited for my application which is why I thought to PWM output. I may re-think that, unsure at this point.

[quote]


New ( offline )
Posts: 6
Posted: 2012-04-10 16:42 
ok, thinking out loud here... since there are 6 PWM outputs on this board, could I power more than 1 light with the PWM output? I've never used RGB LED's, so I know nothing about them at all except what I am reading.

Questions:

* Can I power more than 1 RGB LED off a single PWM output?

* Can I change colors with a PWM output? (I'm pretty sure this is yes :) )

* Can I turn the LED's completely off as well?


If so, then I will get some RGB LED's like: http://www.robotshop.com/seeedstudio-5mm-common-anode-rgb-leds-100-pack.html and use the following to complete the project:

Microcontroller: http://www.robotshop.com/arduino-nan-v-3-4.html

2 Sensors: http://www.robotshop.com/sharp-gp2d120-ir-range-sensor-4-30-cm-2.html


What else would I need to purchase as a newbie? I've already got a nice breadboard from my engineering days. Do I have to purchase software to program the controller or is that included?


Thanks for all your help so far, BTW.


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Admin ( offline )
Posts: 3728
Posted: 2012-04-11 08:02 
The RGB LEDs you chose don't need a PWM pin - they operate simply using the digital pins. Be careful about current draw - the microcontroller can output about 40-50mA per pin. The PWM pins on the Arduino are also digital pins as well. Set the pins to low to turn them all off. You'll need the appropriate USB cable, and no, the software is free from http://www.arduino.cc

_________________
Coleman Benson

RobotShop inc.
Putting Robotics at your service!™
www.robotshop.com

Lynxmotion
Imagine it. Build it. Control it.™
http://www.Lynxmotion.com


New ( offline )
Posts: 6
Posted: 2012-04-11 10:36 
[quote]

With the digital pins I wouldn't be able to fade the colors would I? I don't HAVE to do that, but it would be cool :)


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Admin ( offline )
Posts: 3728
Posted: 2012-04-11 11:48 
Correct - but you can still play with that using the analog pins too.

_________________
Coleman Benson

RobotShop inc.
Putting Robotics at your service!™
www.robotshop.com

Lynxmotion
Imagine it. Build it. Control it.™
http://www.Lynxmotion.com


 

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