A low cost sunlight analyser and data logger measuring radiation

摘要: Abstract Growing conditions in the early stages of crop development can be critical to eventual yield. This is true for a wide variety crops such as lettuce, maize and rice. These include not only soil quality, moisture temperature, but also quality duration available sunlight. A simple measure ‘brightness’ however good indication ‘quality’ sunlight available. Research has shown that presence or absence specific wavelengths light (particularly infra-red (IR), red blue) significantly affect photosynthesis hence growth. Further, over exposure plant tissue high levels ultra violet radiation prove damaging. IR known scattered by weak cloud haze, absorbed moderate conditions, resulting lower reaching ground. Ultra capable penetrating even cloud. The total amount received an immature its later yield, determining whether worth harvesting, influence use fertilizers real time control supplementary, wavelength illumination. paper discusses results from low cost, time, stand-alone LED based analyser data logger making both quantitative qualitative measures bands, distinguishing ranging direct sun, through moonlight. unit costs less than 10 Euros give excess 4 months unattended monitoring logging using 3 alkaline AA batteries, storing internal 32Mbit Flash EEPROM transmitting via 2.4 GHz RF link.