Design of a battery-less smart sensor platform using Texas instrument (TI) MSP430 ultra-low power microcontroller (MCU)

• Main Author: Wu, Zhixiang
• Other Authors: Siek Liter
• Format: Final Year Project
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
• Online Access: http://hdl.handle.net/10356/60179
• Institution: Nanyang Technological University

Due to advancement of the CMOS technology in the power consumption of a microcontroller (MCU) as well as the wireless identification and sensing platform (WISP), it is possible now to design a zero energy WISP. The WISP designed in this final year project consists of several important components. They are the MCU itself (MSP430G2553), temperature sensor (TMP100) and the low-frequency (LF) transponder (TMS37157). The energy required for powering up the sensor platform is entirely harvested from the LF Reader. As low-power consumption is the key factor in motivating this entire project, the sensor platform is therefore designed to operate on the lowest power budget possible and yet still able to perform and sustain for its minimal operations required. This project is centered on the MCU as it acts as the brain for the entire sensor platform and is therefore responsible for the all the communication between the internal components. By utilizing the Serial Peripheral Interface (SPI) communication mode and Inter Integrated Circuit (I2C) communication mode available in the MCU, the communication between the MCU, temperature sensor and the LF transponder is realized. Some of the key functions of the MCU such as the low-power modes were also employed extensively in order to fulfil the tight power budget available for the entire platform. The flow of communication starts with a wake up signal coming from the LF transponder. The MCU then wakes up from the LPM and perform its intended operation and entering LPM again once all the required instructions and operations is carried out. The overall system interface and program is designed with the knowledge and constraint of the allowable power budget.