综合的ADC_pic源代码

这是经过验证可用的ADC代码，具有很高的参考值. * Basic A2D sample code for an PIC16F87x device. * This code willl set up the A2D module to return an * 8-Bit result. If greater precision is needed, a 10-Bit * result can be returned if read_a2d() is modified to * return the short ((ADRESH<<8)+(ADRESL)). Note also that * ADCON1 should be set to 0x80 in the init_a2d() routine * instead of zero.