User interface design for LPC2138 to configure wireless sensor node parameters

Power consumption is the key challenge of designing a reliable wireless sensor embedded computational system. For a deployed WSN, the infrastructure of various motes is built using the traditional 8-bit 5V DC operative microcontrollers because of its low-cost. There exist many schemes and power reduction techniques for a single node. However, the power consumption for a Coordinator node wherein the user or other network is typically interfaced is often been ignored since the same 8-bit microcontroller is used as the infrastructure to design. This paper suggests the usage of ARM LPC2138 as the MCU to be replaced in Coordinator irrespective of other node´s architecture of WSN. The efficient, clean and bug-free device driver implementation to connect a LCD for displaying messages is presented in the first part of the paper. The user input through a low-cost dumb conventional 4×3 matrix keypad is implemented and suggested in the second part of the paper. The integration of these two drivers with the UART driver for achieving WSN related prototype is discussed in the next phase of the paper. This firmware is implemented using Keil4 IDE and the hardware design is validated using Proteus7.8i. The firmware debugging techniques strategy being opted for the implemented drivers is illustrated along with the Results and a note with the current work at the end of the paper.