One of the buzz words in the Information Technology is the Internet of Things (IoT). In coming years, IoT will transform the objects which are present in the real world into virtual objects. IoT keep us informed about the status of objects and controls of things in a sensor network. Sensor node comprises of the sensor, microcontroller and RF transceiver. A microcontroller is an integrated circuit which basically performs one task and executes particular application. It contains programmable in/out peripherals, memory, and processor. Microcontrollers are mostly designed in view of embedded and are used to automatically controllable systems. In digital system design microcontrollers and field programmable gate arrays (FPGAs), both are widely used. Microcontroller based devices are becoming increasingly widespread. On one hand, high speed, power, and falling prices make them an obvious choice whereas fast-growing popularity of FPGAs, the availability of powerful development tools and the increase in speed and high density have made FPGA based systems an alternative choice. Sensor node controller is going to develop using VHDL with behavioral modeling which is an abstract model of the controller and breaks down of the system into subcomponents and functional blocks.