The technique is designed to optimize the energy consumption for sensor processing layer in Internet of Things (IoT). Sleep time calculation algorithm is built on the gateway to predict the sleep time of sensor nodes according to information quality, information history, and remaining battery capacity. The power reduction techniques are designed to turn off the functions of node sensors in sleep mode. Sensor Node consumes 2.84% of battery power, compared to 12.52% of reading data in a given cycle in 2 hours. Transmission results are 100% successful rate with distances less than 500 m. The sensor node consumes 4.47mAh to 28.8mA, corresponding to one AA battery that can sustain the node from 15.6 hours to 11 days. The study also calculates the solar cell solution provided for sensor nodes.