unsigned int read_analog_channel(int channel)
     {
      ADCHS = channel; // channal is the input  analoge
      ADCSSL = 0;
      ADCON3 = 0x0205; // Manual Sample, ADCS=5 -> Tad = 3*Tcy = 0.1us
      ADCON2 = 0;     // one sample
      ADCON1bits.ADON = 1; // turn ADC ON
      ADCON1bits.SAMP = 1; // start sampling then ...
     // after 3Tad go to conversion
      while (!ADCON1bits.DONE); // conversion done?
      ADC value = ADCBUF0