对A0 A1 A2 三个通道进行电压检测,ADC结果存于 ad_value[3] 数组中.并用 result[X]= ((Avcc * ad_value[X] )/ 1023 的公式来计算电压值 .程序中写到的 "*1000" 是将结果扩大1000倍,保留3位小数点-Right A0 A1 A2 3 channel voltage detector, ADC results stored in ad_value [3] array. And with the result [X] = ((Avcc* ad_value [X])/1023 of the formula to calculate the voltage value. Program writes The " * 1000"　is the result of the expansion will be 1000 times, retaining three decimal places