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1  Using Arduino / LEDs and Multiplexing / Re: Very Simple LED Question on: January 29, 2013, 12:50:12 pm
Thank you all very much for the help.  As far as I understand, I will be using PWM to dim the light to a certain point. 

I am planning to run a light intensity (irradiance) sensor with it [TSL235R (https://www.sparkfun.com/products/9768)].  Will the pulses of light interrupt the reading of irradiance?  Such as, if I take a 500 ms reading, will the on/off (say 5ms on 5ms off) will it screw up the reading in some way?  It's kind of blowing my mind right now. 
2  Using Arduino / LEDs and Multiplexing / Very Simple LED Question on: January 26, 2013, 12:40:26 pm
I'm planning to run a single LED at varying voltages (and presumably light intensities).  Is this possible, or are LED's simply on or off (without varying intensities)?  Thank you all in advance. 

MP
3  Using Arduino / Sensors / Laser to Light Sensor on: January 13, 2013, 07:34:35 pm
All,

I'm working on a project involving a light-to-frequency converter IC (TSL235R) measuring something similar to light intensity (irradiance actually in uW/cm^2) and a red LED as a light emitter. I'm planning to replace the LED with a laser in order to better control the emitting part of the system.  I'm not very experienced with light/lasers, but would it be possible to operate an LED and laser in the same wavelength?  Also, if they are the same wavelength, would their irradiance be the same at the same voltage?

Thank you.
4  Using Arduino / Sensors / TSL235R Op Conditions on: November 29, 2012, 01:31:36 pm
I have a problem with this light intensity sensor (shown below).  We are using an LED and basically running items of varying opacity between it and the sensor.  We have isolated both the LED and sensor from external light.  Therefore the light intensity range will vary with the items between the sensor and LED (the transparency of the obstruction changes).  I'm having trouble understanding the RANGE the sensor will operate at.  We are operating a red LED (presumably 635nm wavelength) with a 3.3v source from the arduino.  We are operating the sensor with the 5v pin. 

In other words, we are operating at the exact parameters listed in the data sheet (and shown below).  BUT, only some of the wavelengths measured are between the 200-300 kHz range.  Does this mean the range is only accurate/operable at these ranges?  Or does this mean that the frequency should be in the 200-300 kHz range? Thank you all in advance.
___________________________________________________________________
Operating Characteristics at VDD = 5 V, TA = 25°C
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

f Output frequency for
Ee = 430 μW/cm2, λp = 635 nm

Min: 200 kHz
Typ: 250 kHz
Max: 300 kHz
___________________________________________________________________
Data sheet:
http://www.parallax.com/Store/Sensors/ColorLight/tabid/175/CategoryID/50/List/0/SortField/0/Level/a/ProductID/783/Default.aspx

Basics of code:
http://arduino.cc/forum/index.php/topic,21536.0.html

THANK YOU!!!
5  Community / Bar Sport / Maker Presentation - Cost of Starting a Business on: November 08, 2012, 08:44:10 pm
All,

I guess this is me welcoming me to the forums.  Recently I bought an Arduino Uno due to my love of design, software, mechanical engineering, and even Matlab.  As a mechanical engineering student, I have to present on an engineering related issue.  I have chosen the Maker culture as a topic (more specifics in a second).  Arduino is clearly a part of this, and although I'm not yet active, I've made the first steps in one day being so. 

I want to introduce other students to the maker culture and to mainly introduce them to the changes the Maker culture is spearheading in industry (manufacturing for small businesses/startups mainly).  I am personally amazed at being able to draft, prototype, test, manufacture, and ship for very little money, in a very short amount of time. 

Long story short, I am wondering if anyone could suggest some reading materials for this (especially business cases).  I am currently reading "Makers" by Chris Anderson as a backbone for my presentation.  He talks of companies being able to start on a credit card budget.  I also think Amazon web services are amazing, so any useful applications of MAKER TOOLS for small businesses would apply here.  Thank you all!
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