///////////////////////////////////////////////////////////////////////////
////   Library for a 74165 Expanded Input Chip                         ////
////                                                                   ////
////   Any number of these chips may be connected in serise to get     ////
////   8 additional  inputs per chip.  The cost is 3 I/O pins for      ////
////   any number of chips.                                            ////
////                                                                   ////
////    read_expanded_inputs(eo);  Reads the array ei from the chips   ////
////                                                                   ////
///////////////////////////////////////////////////////////////////////////
////        (C) Copyright 1996,1997 Custom Computer Services            ////
//// This source code may only be used by licensed users of the CCS C   ////
//// compiler.  This source code may only be distributed to other       ////
//// licensed users of the CCS C compiler.  No other use, reproduction  ////
//// or distribution is permitted without written permission.           ////
//// Derivative programs created using this software in object code     ////
//// form are not restricted in any way.                                ////
////////////////////////////////////////////////////////////////////////////

#IFNDEF EXP_IN_ENABLE

#define EXP_IN_ENABLE   PIN_B3
#define EXP_IN_CLOCK    PIN_B1
#define EXP_IN_DI       PIN_B2
#define NUMBER_OF_74165 1

#ENDIF


void read_expanded_inputs(byte *ei) {
  byte i;

  output_high(EXP_IN_CLOCK);
  output_low(EXP_IN_ENABLE);      // Latch all inputs
  output_high(EXP_IN_ENABLE);

  for(i=1;i<=NUMBER_OF_74165*8;++i) {      // Clock in bits to the ei structure
    shift_left(&ei,3,input(EXP_IN_DI));
    output_low(EXP_IN_CLOCK);
    output_high(EXP_IN_CLOCK);
  }
  output_low(EXP_IN_ENABLE);
}