ir_NEC.cpp

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#include "IRremote.h"
 
//==============================================================================
//                           N   N  EEEEE   CCCC
//                           NN  N  E      C
//                           N N N  EEE    C
//                           N  NN  E      C
//                           N   N  EEEEE   CCCC
//==============================================================================
 
#define NEC_BITS          32
#define NEC_HDR_MARK    9000
#define NEC_HDR_SPACE   4500
#define NEC_BIT_MARK     560
#define NEC_ONE_SPACE   1690
#define NEC_ZERO_SPACE   560
#define NEC_RPT_SPACE   2250
 
//+=============================================================================
#if SEND_NEC
void  IRsend::sendNEC (unsigned long data,  int nbits)
{
    // Set IR carrier frequency
    enableIROut(38);
 
    // Header
    mark(NEC_HDR_MARK);
    space(NEC_HDR_SPACE);
 
    // Data
    for (unsigned long  mask = 1UL << (nbits - 1);  mask;  mask >>= 1) {
        if (data & mask) {
            mark(NEC_BIT_MARK);
            space(NEC_ONE_SPACE);
        } else {
            mark(NEC_BIT_MARK);
            space(NEC_ZERO_SPACE);
        }
    }
 
    // Footer
    mark(NEC_BIT_MARK);
    space(0);  // Always end with the LED off
}
#endif
 
//+=============================================================================
// NECs have a repeat only 4 items long
//
#if DECODE_NEC
bool  IRrecv::decodeNEC (decode_results *results)
{
    long  data   = 0;  // We decode in to here; Start with nothing
    int   offset = 1;  // Index in to results; Skip first entry!?
 
    // Check header "mark"
    if (!MATCH_MARK(results->rawbuf[offset], NEC_HDR_MARK))  return false ;
    offset++;
 
    // Check for repeat
    if ( (irparams.rawlen == 4)
        && MATCH_SPACE(results->rawbuf[offset  ], NEC_RPT_SPACE)
        && MATCH_MARK (results->rawbuf[offset+1], NEC_BIT_MARK )
       ) {
        results->bits        = 0;
        results->value       = REPEAT;
        results->decode_type = NEC;
        return true;
    }
 
    // Check we have enough data
    if (irparams.rawlen < (2 * NEC_BITS) + 4)  return false ;
 
    // Check header "space"
    if (!MATCH_SPACE(results->rawbuf[offset], NEC_HDR_SPACE))  return false ;
    offset++;
 
    // Build the data
    for (int i = 0;  i < NEC_BITS;  i++) {
        // Check data "mark"
        if (!MATCH_MARK(results->rawbuf[offset], NEC_BIT_MARK))  return false ;
        offset++;
        // Suppend this bit
        if      (MATCH_SPACE(results->rawbuf[offset], NEC_ONE_SPACE ))  data = (data << 1) | 1 ;
        else if (MATCH_SPACE(results->rawbuf[offset], NEC_ZERO_SPACE))  data = (data << 1) | 0 ;
        else                                                            return false ;
        offset++;
    }
 
    // Success
    results->bits        = NEC_BITS;
    results->value       = data;
    results->decode_type = NEC;
 
    return true;
}
#endif