(Project on hold as of 1/5/18)

* Paper: http://ohm.bu.edu/~hazen/LedArray/LED%20array%20and%20controller.pdf

{{{
My name is Mikel Garcia-Marcos and I am an Associate Professor of
Biochemistry at the medical campus. I am writing to inquire about a
possible project. I would like to recreate something identical or very
similar to what is described in the attached manuscript (scroll down
to "Support Protocol 1: Construction of programmable LED light device"
on page 10 and the related Figure 2 on page 27).


Basically, I would like to build an array of LED lights that fits the
dimensions of a small plate used for culturing cells and that can be
controlled in terms of intensity and duration of "on" and "off"
cycles.
}}}


== Parts cost / sourcing ==

||= Qty =||= Item =||= Price Ea=||= Total =||= Link =||
|| 1 || Arduino Uno || $22.00|| $22.00|| ||
|| 1 || !SainSmart LCD / keypad shield || $11.00|| $11.00|| [https://www.sainsmart.com/products/lcd-keypad-shield-for-arduino-duemilanove-uno-mega2560-mega1280 link] ||
|| 1 || !BuckBlock Luxdrive LED driver || $18.00|| $18.00|| [https://www.ledsupply.com/led-drivers/buckblock-dc-led-driver?gclid=CjwKCAiA693RBRAwEiwALCc3u3W5YCNsb5PZpmAPolBVqn0dGDXfce29f38SyyW-Y3BnuC8cVgZtMxoCHYoQAvD_BwE link] ||
|| 12 || 470nm LED module || $6.00|| $72.00|| [https://www.luxeonstar.com/470nm link] ||
|| 1 || Power supply 15V 1.5A || $18.00|| $18.00|| [https://www.digikey.com/product-detail/en/cui-inc/SWI24-15-N-P5/102-3629-ND/5415100 link] e.g. ||
|| 3 || TIP120 darlington || $0.85|| $2.50|| [https://www.digikey.com/product-detail/en/on-semiconductor/TIP120TU/TIP120TUFS-ND/1052473 link] e.g. ||
|| 1 || Other misc parts || $10.00|| $10.00|| ||
|| 1 || Custom PC board || $100.00|| $100.00|| ExpressPCB Miniboard (lot of 3) ||
|| || Total (est) || || $250.00|| ||

== Reference ==

* Heatsinks:  https://www.luxeonstar.com/130mm-x-70mm-1.5-degree-cw-alpha-heat-sink
* Thermalloy:  https://www.digikey.com/product-detail/en/aavid-thermalloy/645002F00000G/HS509-ND/6558793
* Trays:  https://mx.vwr.com/assetsvc/asset/es_MX/id/7830342/contents

The original Arduino software uses analogWrite() to set the intensity.  This is implemented using PWM on the Arduino at 490 or 980 Hz depending on the pins.  6 pins are available so 6 LED groups can be controlled independently (with modifications to the software which currently supports only 3 channels)

A mystery is that in the original design one LED controller is apparently shared by 3 groups of 12 LEDs.  Perhaps only one group is ever on at once?  Need to discuss with the customer.