The CCD and fixed
focus lens is housed on a separate circuit board connected to the motherboard
via a 15cm ribbon cable. A shorter cable has been ordered from Pimoroni,a
specialist Raspberry Pi supplier. The lens enclosure was modeled in SketchUp
using the Raspberry Pi reference data for the camera dimensions, allowing for
an enclosure that holds the CCD and lens firmly, while allowing for three
filters ( high pass, low pass, and blue) to be swapped out in front of the
lens.
The model was
then exported to OBJ file format and uploaded to ShapeWays, a Dutch 3d printing
service, who printed it in laser-sintered Nylon 6. A $25 discount from a customer
satisfaction survey bought the cost for the print down to R45. Following
verification and testing, this part will be made available for other users toprint.
An IR block filter, blocking out IR light and
allowing only visible light through, is sought. Suppliers on eBay produce
filters for astronomical imaging that may be suitable. Two layers of exposed
black and white film have traditionally been used as a filter to block out
visible light and allow infrared light through. The blue filter, for monitoring
vegetation health, is supplied with the camera.
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