>>Back to Past Projects Project: SEPT Date:March 2008 Summary: SEPT - Super Efficient Photosynthesis. A grow light made from red and blue LEDs being pulsed. This light fits inside a Altoids container and requires less than 1.1W of energy to grow a 6"x6"x6" space. Lights can be chained to grow more plants. Total lumens = 111. Plants need primarily red (680nm) light to grow and a small amount of blue (440nm) light. By pulsing the LEDs at 720Hz or higher the plant can achieve maximum growth with a minimal amount of energy. Images:

LED Details:

I've based my LED project on this paper.

Pulse Frequency	720Hz
red LED wavelength (nm)	633
red LED mcd	3920
red LED view	60
red LED lumens	3.3
red LED mA	50
red LED V	2.15
red LED qty	30
blue LED wavelength (nm)	469
blue LED mcd	392
blue LED view	120
blue LED lumens	1.2
blue LED mA	30
blue LED V	3.4
blue LED qty	10

Parts:

Part#	Description	Vendor	Price	qty	sub-total	shipping
gmv1	pcb	barebonespcb	6.57	1	6.57	17.14
atmega169	atmega169pv-8au-nd	digi-key	3.81	1	3.81
555-167	rj45 jack	digi-key	0.56	2	1.12
cat-5	cable per 1'	thrift	0.06	2	0.11
475-1304-1-ND	blue led	digi-key	0.62	10	6.20
475-1321-1-ND	red led	digi-key	0.31	30	9.30
P150ACT-ND	150 ohm 0805	digi-key	0.02	25	0.60
EG1847-ND	power switch	digi-key	0.85	1	0.85
uln2003ad	transistor	digi-key	0.32	4	1.28
NJM#7805FA-ND	5V Reg. 7805	digi-key	0.50	1	0.50
P993-ND	1uF decouple	digi-key	0.06	2	0.12
SAM1074-50-ND	jtag	digi-key	0.22	1	0.22
A24923-ND	rj45 plug	digi-key	0.26	2	0.52	8.00

Files:

1. schematic (pdf)
2. gerbers (zip)
3. schematic (gschem format)
4. pcb (pcb format)
5. source code(html)
6. source (tarball)

Purchase:
I have sold out of grow lights. Thank you for your purchases.

Questions: