| 1. | The analog circuit of the system in this thesis is composed with pre - positive circuit of 4 - probe electrode sensor and temperature - measure circuit . the digital circuit regards at89c55 single - chip as core , expanding ad , key in , display out and memory peripheral chips 系统硬件的模拟电路部分设计了四电极传感器前置模拟电路以及热敏电阻测温电路;数字电路部分以at89c55单片机为核心,扩展了a / d ,键盘输入,显示输出等基本功能。 |