Spindle flowmeter , a new type of differential pressure flowmeter , is used as the sensor of flow measurement . and aiming for a small and intelligent design , we use the mcu named sst89e564rd as the main controller , the leds and the keyboard as the user interface 本著小型化、智能化的原則,該積算儀采用sst公司的微控制器sst89e564rd作為控制核心,并設(shè)計(jì)了由數(shù)碼管和矩陣式鍵盤組成的人機(jī)對(duì)話接口。