When aiming to reduce the maintenance costs of environmental sensor systems in industrial factories and plants, sensor power consumption needs to be lowered. This paper describes a method for reducing the power consumption of sensor systems by utilizing the standby functions of a microcontroller. In concrete terms, the frequency of sensor measurements is reduced and the system is kept in the standby condition for as long as possible. Furthermore, abnormality detection is also performed while remaining in this state.
The RL78/G11 16-bit microcontroller IC from Renesas provides numerous peripheral functions that are available in standby mode. With a suitable combination of these functions, it becomes possible to realize abnormality detection and alarm output without having to take the chip out of standby mode.