/* C52ADC.C
   4-channel 8-bit resolution ADC and 6-bit input port for C52-EVB
   Copyright 2000 Wichit Sirichote
   start conversion by high to low signal at RB0,
   40-bit data is then shifted out through PA4 with low-to-high trnasition at RB0
   The format is started from ADC0,ADC1,ADC2,ADC3,port_B
   ----________---___---___---___---___---___---___---~
      ^        ^
        ~60uS LSB
   after high-to-low starting 711 chip to read analog input and port B, at least 60 microseconds
   required before low-to-high data shifted out to begin.
*/

#include <C52ADC.H>
#fuses   RC,NOPROTECT,NOWDT,PUT,BROWNOUT

byte buffer[5];

read_analog()
{
   byte i;
   for(i = 0; i < 4; i++)
   {
      set_adc_channel(i);
      delay_us(5);
      buffer[i] = read_adc();
   }

}

read_portB()
{
   buffer[4] = port_B;
}

send_data_out()
{
   byte i;
for(i=0;i<40;++i){    // 5 bytes
   while (!input(PIN_B0));
	output_bit(PIN_A4,shift_right(buffer,5,0));
   while (input(PIN_B0));}   // shifted out when RB0 change from LOW to HIGH
}
/*This shifts 40 bits out Pin_A4, LSB first.*//*This shifts 40 bits out Pin_A4, LSB first.*/

//    ___---___---___---___---____
//      LSB ......................... MSB


main() {
   port_b_pullups(TRUE);
	setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
	setup_port_a(ALL_ANALOG);
	setup_adc(ADC_CLOCK_INTERNAL);

while(1){
   while(input(PIN_B0));   // wait High to Low trigger read signal from C-52EVB
       read_analog();
       read_portB();
       send_data_out();    // send 40 bits in buffer array to PIN_A4
    }


}