Commodore Amiga CDTV: new protocol or RCA-38(old)?
Posted: Tue Feb 07, 2017 3:55 am
Please have a look at this issue. It is claimed that this is a new protocol. As I ("bengtmartensson") wrote, decodeir (within IrScrutinizer) identifies the signal as RCA-38(Old) (D=8) However, I get the impression that the timing differences may be significant.
Searching for this device gave me only a Lirc file. This also decodes with IrScrutinizer as RCA-38(old), but with different device number (0), although the timings appear to be off.
This is the C code written:
Is this a new protocol, or is it RCA-38(old)? Is DecodeIR too tolerant here?
Searching for this device gave me only a Lirc file. This also decodes with IrScrutinizer as RCA-38(old), but with different device number (0), although the timings appear to be off.
This is the C code written:
Code: Select all
#define CDTV_BITS 24
// timing intervals in usec
#define CDTV_HDR_MARK 8850 // start burst
#define CDTV_HDR_SPACE 4450 // pause after start
#define CDTV_BIT_MARK 350 // pulse
#define CDTV_ONE_SPACE 1250 // receive a '1'
#define CDTV_ZERO_SPACE 450 // receive a '0'
#define CDTV_RPT_SPACE 2250 // repeat signal
// message sizes measured in raw pulses
#define CDTV_RAW_REPEAT_LENGTH 4 // CDTV_HDR_MARK + CDTV_HDR_SPACE + CDTV_BIT_MARK
#define CDTV_RAW_SIGNAL_LENGTH 52 // CDTV_HDR_MARK + CDTV_HDR_SPACE + CDTV_BITS * (CDTV_BIT_MARK + CDTV_ZERO_SPACE | CDTV_ONE_SPACE)
//+=============================================================================
#if SEND_CDTV
void IRsend::sendCDTV(unsigned long data, int nbits) {
// set IR carrier frequency
enableIROut(40);
// send header
mark(CDTV_HDR_MARK);
space(CDTV_HDR_SPACE);
// send data
for (unsigned long mask = 1UL << (nbits - 1); mask; mask >>= 1) {
if (data & mask) {
mark(CDTV_BIT_MARK);
space(CDTV_ONE_SPACE);
} else {
mark(CDTV_BIT_MARK);
space(CDTV_ZERO_SPACE);
}
}
// send footer
mark(CDTV_BIT_MARK);
// always end with the LED off
space(0);
}
#endif
Is this a new protocol, or is it RCA-38(old)? Is DecodeIR too tolerant here?