Today sensors are all over the place. We undervalue it, yet there are sensors in our vehicles, in our advanced cells, in processing plants controlling CO₂ discharges, and even in the ground observing soil conditions in vineyards. WSN surprisingly cover the broad area of applications, and research and technology advance continuously increase their application field. The internet of things (IoT) introduced in correspondence to WSNs. WSN was traditionally recognized fundamental enabler for the IoT standard. WSNs make IoT applications valuable for both sensing and actuation. In this paper we design the microcontroller specifically for IoT based wireless sensor network. It takes the data from the different sensor node and send it to the gateway sensor node. We also design the Serial communication Peripheral (SPI) so that fast data transmission can be obtained very easily. Internal memory is used in the controller to hold the data for a short period, and then it is transmitted to the other wireless sensor node.