This document discusses the design and implementation of a microcontroller in an FPGA for Internet of Things applications. It begins with an introduction to sensor nodes, microcontrollers and FPGAs. It then reviews literature on microcontroller architectures and FPGA design. The paper describes developing a behavioral model of an 8-bit microcontroller in VHDL and synthesizing it for the Xilinx Spartan 3E FPGA. Simulation results showed the basic functionality of the microcontroller was achieved. The modular VHDL design allows expanding it to develop more advanced microcontrollers.