//置IO口为高,输入状态<br />ADCOUT = 1;<br />SCLK = 0;<br />//启动转换<br />ADCCS = 0;<br />NOP();<br />//bit7不需要时钟<br />if(ADCOUT)<br /> rbyte = rbyte + 0x01;<br />else <br /> rbyte = rbyte + 0x00;<br />rbyte = rbyte << 1;<br />//读取bit6~bit0<br />for(i = 0; i < 7; i++)<br />{<br /> SCLK = 1;<br /> NOP();<br /> //下降沿读取数据<br /> SCLK = 0;<br /> if(ADCOUT)<br /> rbyte = rbyte + 0x01;<br /> else <br /> rbyte = rbyte + 0x00;<br /> rbyte = rbyte << 1; <br />}<br />//需要第8个时钟<br />SCLK = 1;<br />NOP();<br />SCLK = 0;<br />//开始下次转换<br />ADCCS = 1;<br />--------------------------------------------------<br />完全按照datasheet时序要求来的,Vref+ = 4V;Vref- = 0;<br />是不是比较电压有关? |
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