基于MSP430的高精度微功耗可存取数字压力表设计

采用MSP430F149作为总控制器,设计了高精度微功耗数字压力表。压力传感器采用恒流源供电,其输出采用AD7714进行A/D转换,以ADR291产生的恒压作为其参考电压。采用模块化供电和分时数据采集的策略降低系统功耗,采用自主设计的MOSFET电源开关切断不工作模块的电源。运用基于变化速率的均值滤波方法对采集的压力数据进行滤波,最后采用多点校准的方式对压力表进行校准。采用简化的文件系统实现实时压力数据的存储与回放。压力表精度达到0.25‰以上,在采用4节5#干电池供电的情况下,正常连续工作时间达3 000h以上。

Design of Accessable Digital Pressure Gauge of High Precision and Micro-power Consumption Based on MSP430

Taking MSP430F149 as the master controller,a digital pressure gauge of high precision and micro-power consumption was designed,in which,the A/D conversion of pressure sensor output which having a constant power supply and taking constant voltage from ADR2914 for reference can be implemented though AD7714,and the strategy of modular power supply and timesharing data acquisition can be used to reduce system power consumption,as well as the self-designed MOSFET power switch can be taken to turn off the power of module which doesn’t work.Having the mean filtering method which based on change rate taken to filter the pressure data collected,and the multi-points calibration method employed to calibrate the pressure gauge,as well as the simplified file system used to store and replay pressure data show that the precision of the pressure gauge can exceed 0.25‰,and its continuous working time can be more than 3 000 hours when it’s powered with 4 AA 1.5V batteries.