A multiple function illuminance meter was developed based on BH1750, a digital ambient light sensor. Besides illuminance, the meter can measure temperature and humidity, even conduct wireless communication each other. Low voltage and low power Micro-controller STC12LE5A60S2 was used as processing unit, radio transceiver IA4420 with strong anti disturbance capacity and the simplest application circuit was used as communication element, SHT11 was used as sensor element, besides BH1750. A data Tx/Rx method through nIRQ pin of IA4420 was presented, which do Tx/Rx according to content of status register in interrupt service routine. Illuminance contrast measurement between commercial illuminance meters was done and results were given.