基于 ADuC7061 微處理器(qi)的土壓(ya)傳感(gan)器(qi)硬件系統原理圖，如(ru)圖 3 所示。硬件系統包(bao)括系統電源電路(lu)以及系統外圍(wei)電路(lu)兩部分。

圖中(zhong)(zhong)左上(shang)部分為(wei)(wei)(wei)(wei)系(xi)統電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)路(lu)，電(dian)(dian)(dian)(dian)源(yuan)芯片(pian)采(cai)用ADI 公 司 低 壓(ya)(ya) 差 線 性(xing) 穩 壓(ya)(ya) 器(qi)(qi)(qi)(qi) ADP3330ARTZ-2.5， 芯片(pian)可(ke)接(jie)(jie)受電(dian)(dian)(dian)(dian)壓(ya)(ya)輸(shu)(shu)入(ru)范圍為(wei)(wei)(wei)(wei) 2.9~12V，輸(shu)(shu)出(chu)穩定電(dian)(dian)(dian)(dian)壓(ya)(ya)為(wei)(wei)(wei)(wei)2.5V。在(zai) 25℃溫(wen)度環境(jing)中(zhong)(zhong)，輸(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)壓(ya)(ya)精度為(wei)(wei)(wei)(wei) ±0.7%；在(zai) -40~85℃溫(wen)度范圍內，輸(shu)(shu)出(chu)電(dian)(dian)(dian)(dian)壓(ya)(ya)精度為(wei)(wei)(wei)(wei) ±1.4% 。系(xi)統電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)路(lu)主要為(wei)(wei)(wei)(wei)微處(chu)理(li)器(qi)(qi)(qi)(qi)和(he)傳感器(qi)(qi)(qi)(qi)提供工作電(dian)(dian)(dian)(dian)源(yuan)。對(dui)(dui) 于(yu) ADuC7061 微 處(chu) 理(li) 器(qi)(qi)(qi)(qi)， 需 要 為(wei)(wei)(wei)(wei) 其 數 字 電(dian)(dian)(dian)(dian) 源(yuan) 端 口(kou)DVDD 和(he)模擬電(dian)(dian)(dian)(dian)源(yuan)端口(kou) AVDD 提供（2.5V±5% ）電(dian)(dian)(dian)(dian)壓(ya)(ya)以保證正常工作。對(dui)(dui)于(yu)應(ying)(ying)變(bian)電(dian)(dian)(dian)(dian)橋激(ji)勵電(dian)(dian)(dian)(dian)源(yuan)，由(you)于(yu)應(ying)(ying)變(bian)電(dian)(dian)(dian)(dian)橋信(xin)(xin)號最(zui)終會(hui)由(you)微處(chu)理(li)器(qi)(qi)(qi)(qi)中(zhong)(zhong) ADC 模塊數字化，因此可(ke)直接(jie)(jie)選用微處(chu)理(li)器(qi)(qi)(qi)(qi)模擬電(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)壓(ya)(ya)并采(cai)用比率測量方式，實現(xian)應(ying)(ying)對(dui)(dui)變(bian)電(dian)(dian)(dian)(dian)橋的(de)激(ji)勵 。系(xi)統外(wai)圍電(dian)(dian)(dian)(dian)路(lu)以微處(chu)理(li)器(qi)(qi)(qi)(qi)為(wei)(wei)(wei)(wei)中(zhong)(zhong)心，主要包括復(fu)(fu)位電(dian)(dian)(dian)(dian)路(lu)、通信(xin)(xin)電(dian)(dian)(dian)(dian)路(lu)以及調(diao)零電(dian)(dian)(dian)(dian)路(lu)。復(fu)(fu)位電(dian)(dian)(dian)(dian)路(lu)基于(yu)上(shang)電(dian)(dian)(dian)(dian)復(fu)(fu)位方式，即微處(chu)理(li)器(qi)(qi)(qi)(qi)復(fu)(fu)位端口(kou)直接(jie)(jie)接(jie)(jie)上(shang)拉電(dian)(dian)(dian)(dian)阻 R3 拉高(gao)。對(dui)(dui)于(yu)通信(xin)(xin)電(dian)(dian)(dian)(dian)路(lu)，自定義五線 JTAG 通信(xin)(xin)接(jie)(jie)口(kou)，實現(xian)代碼下(xia)載和(he)調(diao)試 [8]。對(dui)(dui)于(yu)調(diao)零電(dian)(dian)(dian)(dian)路(lu)，直接(jie)(jie)在(zai)微處(chu)理(li)器(qi)(qi)(qi)(qi)外(wai)部中(zhong)(zhong)斷(duan)觸發引腳(jiao) IRQ0 接(jie)(jie)入(ru)電(dian)(dian)(dian)(dian)平(ping)控制器(qi)(qi)(qi)(qi)件(jian)，設(she)置特定電(dian)(dian)(dian)(dian)平(ping)觸發中(zhong)(zhong)斷(duan)，之(zhi)后依靠(kao)軟件(jian)實現(xian)調(diao)零。為(wei)(wei)(wei)(wei)了減小整個硬件(jian)系(xi)統尺寸，電(dian)(dian)(dian)(dian)平(ping)控制器(qi)(qi)(qi)(qi)件(jian)選用封裝尺寸僅為(wei)(wei)(wei)(wei) 3×6mm 的(de)微動(dong)開關實現(xian)。