Ultra-low Power Self-powered Wireless Oxygen Sensor Design

In remote environments where wiring is difficult or difficult to route,the use of wireless sensors is becoming increasingly widespread.Wireless sensors generally refer to the use of wireless signal transmission sensor,and some sensors although the use of wireless means for signal transmission,but the power supply is still wired.Some sensors use battery power,to achieve a real sense of the wireless.However,for some applications,it is not possible to use wired power supply,it is difficult to replace the battery regularly,you must consider the use of self-powered way.Since the self-powered need to obtain energy through the external environment,so the disadvantage is a strong dependence on the external environment,such as wind,solar and so on.Especially for some applications,the volume of the sensor is strictly required,can not use a large volume of solar panels or wind turbines for power supply,the smaller the size of the sensor,access to sufficient power of the external energy more difficult.Therefore,in this case,the system's low-power design is extremely important.This paper presents the design of an ultra-low power self-powered wireless oxygen content sensor.The sensor design is not proposed for a specific engineering application,so it has certain versatility.By modifying the sensor interface circuit,other types of sensors can be connected to realize self-powered wireless signal transmission function,so the utility is high.MSP430 MCU that introduced by Texas Instruments is selected as controller of the system.The wireless transmitting part adopts a capacitor three-point oscillator to realize simple wireless data transmission.The controller and the wireless communication module are normally in a sleep state,and only wake up when data is transmitted,thereby significantly reducing system power consumption.Since the energy such as light energy and mechanical energy in the natural environment could be discontinuous,in order to improve the stability of the system power supply,a two-way energy method based on photocell energy collection and piezoelectric ceramic based vibration energy acquisition is proposed.Photoelectric energy harvesting technology is mature and widely used.Therefore,this paper focus on the vibration energy harvesting.The final design of the self-powered system can meet the needs of the ultra-low-power sensor data acquisition and wireless transmission of this design in the laboratory test environment.