/*

* ir_BangOlufsen.hpp

*

* Contains functions for receiving and sending Bang & Olufsen IR and Datalink '86 protocols

* To receive B&O and ENABLE_BEO_WITHOUT_FRAME_GAP is NOT defined, you must set RECORD_GAP_MICROS to

* at least 16000 to accommodate the unusually long 3. start space.

*

* This file is part of Arduino-IRremote https://github.com/Arduino-IRremote/Arduino-IRremote.

*

************************************************************************************

* MIT License

*

* Copyright (c) 2022-2023 Daniel Wallner and Armin Joachimsmeyer

*

* Permission is hereby granted, free of charge, to any person obtaining a copy

* of this software and associated documentation files (the "Software"), to deal

* in the Software without restriction, including without limitation the rights

* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

* copies of the Software, and to permit persons to whom the Software is furnished

* to do so, subject to the following conditions:

*

* The above copyright notice and this permission notice shall be included in all

* copies or substantial portions of the Software.

*

* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,

* INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

* PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT

* HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF

* CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE

* OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

*

************************************************************************************

*/

#ifndef _IR_BANG_OLUFSEN_HPP

#define _IR_BANG_OLUFSEN_HPP

//==============================================================================

//

//

// Bang & Olufsen

//

//

//==============================================================================

// https://www.mikrocontroller.net/attachment/33137/datalink.pdf

// https://www.mikrocontroller.net/articles/IRMP_-_english#B&O

// This protocol is unusual in two ways:

// 1. The carrier frequency is 455 kHz

// You can build your own receiver as Bang & Olufsen did (check old schematics) or use a TSOP7000

// Vishay stopped producing TSOP7000 since 2009 so you will probably only find counterfeits:

// https://www.vishay.com/files/whatsnew/doc/ff_FastFacts_CounterfeitTSOP7000_Dec72018.pdf

// It is also likely that you will need an oscilloscope to debug a counterfeit TSOP7000

// The specimen used to test this code was very noisy and had a very low output current

// A somewhat working fix was to put a 4n7 capacitor across the output and ground followed by a pnp emitter follower

// Other examples may require a different treatment

// This particular receiver also did receive lower frequencies but rather poorly and with a lower delay than usual

// If you need to parallel a receiver with another one you may need to delay the signal to get in phase with the other receiver

// 2. A stream of messages can be sent back to back with a new message immediately following the previous stop space

// It might be that this only happens over IR and not on the datalink protocol

// You can choose to support this or not:

// Mode 1: Mode with gaps between frames

// Set RECORD_GAP_MICROS to at least 16000 to accept the unusually long 3. start space

// Can only receive single messages. Back to back repeats will result in overflow

// Mode 2: Break at start mode

// Define ENABLE_BEO_WITHOUT_FRAME_GAP and set RECORD_GAP_MICROS to less than 15000

// to treat the 3. start space of 15.5 ms as a gap between messages, which makes decoding easier :-).

// The receiving of a transmission will then result in a dummy decode of the first 2 start bits with 0 bits data

// followed by a 15.5 ms gap and a data frame with one start bit (originally sent as 4. start bit).

// If the receiver is not resumed within a ms or so, partial messages will be decoded

// Debug printing in the wrong place is very likely to break reception

// Make sure to check the number of bits to filter dummy and incomplete messages

// !!! We assume that the real implementations never set the official first header bit to anything other than 0 !!!

// !!! We therefore use 4 start bits instead of the specified 3 and in turn ignore the first header bit of the specification !!!

// IR messages are 16 bits long. Datalink messages have different lengths.

// This implementation supports up to 40 bits total length split into 8 bit data/command and a header/address of variable length

// Header data with more than 16 bits is stored in decodedIRData.extra

// B&O is a pulse distance protocol, but it has 3 bit values 0, 1 and (equal/repeat) as well as a special start and trailing bit.

//

// MSB first, 4 start bits + 8 to 16? bit address + 8 bit command + 1 special trailing bit + 1 stop bit.

// Address can be longer than 8 bit.

/*

* Options for this decoder

*

*/

#define ENABLE_BEO_WITHOUT_FRAME_GAP // Requires additional 30 bytes program memory. Enabled by default, see https://github.com/Arduino-IRremote/Arduino-IRremote/discussions/1181

//#define SUPPORT_BEO_DATALINK_TIMING_FOR_DECODE // This also supports headers up to 32 bit. Requires additional 150 bytes program memory.

#if defined(DECODE_BEO)

# if defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

# if RECORD_GAP_MICROS > 15000

#warning If defined ENABLE_BEO_WITHOUT_FRAME_GAP, RECORD_GAP_MICROS must be set to <= 15000 by "#define RECORD_GAP_MICROS 12750"

# endif

# else

# if RECORD_GAP_MICROS < 16000

#error If not defined ENABLE_BEO_WITHOUT_FRAME_GAP, RECORD_GAP_MICROS must be set to a value >= 16000 by "#define RECORD_GAP_MICROS 16000"

# endif

# endif

#endif

#define BEO_DATA_BITS 8 // Command or character

#define BEO_UNIT 3125 // All timings are in microseconds

#define BEO_IR_MARK 200 // The length of a mark in the IR protocol

#define BEO_DATALINK_MARK (BEO_UNIT / 2) // The length of a mark in the Datalink protocol

#define BEO_PULSE_LENGTH_ZERO BEO_UNIT // The length of a one to zero transition

#define BEO_PULSE_LENGTH_EQUAL (2 * BEO_UNIT) // 6250 The length of an equal bit

#define BEO_PULSE_LENGTH_ONE (3 * BEO_UNIT) // 9375 The length of a zero to one transition

#define BEO_PULSE_LENGTH_TRAILING_BIT (4 * BEO_UNIT) // 12500 The length of the stop bit

#define BEO_PULSE_LENGTH_START_BIT (5 * BEO_UNIT) // 15625 The length of the start bit

// It is not allowed to send two ones or zeros, you must send a one or zero and a equal instead.

//#define BEO_LOCAL_DEBUG

//#define BEO_LOCAL_TRACE

#ifdef BEO_LOCAL_DEBUG

# define BEO_DEBUG_PRINT(...) Serial.print(__VA_ARGS__)

# define BEO_DEBUG_PRINTLN(...) Serial.println(__VA_ARGS__)

#else

# define BEO_DEBUG_PRINT(...) void()

# define BEO_DEBUG_PRINTLN(...) void()

#endif

#ifdef BEO_LOCAL_TRACE

# undef BEO_TRACE_PRINT

# undef BEO_TRACE_PRINTLN

# define BEO_TRACE_PRINT(...) Serial.print(__VA_ARGS__)

# define BEO_TRACE_PRINTLN(...) Serial.println(__VA_ARGS__)

#else

# define BEO_TRACE_PRINT(...) void()

# define BEO_TRACE_PRINTLN(...) void()

#endif

/************************************

* Start of send and decode functions

************************************/

/*

* TODO aNumberOfRepeats are handled not correctly if ENABLE_BEO_WITHOUT_FRAME_GAP is defined

*/

void IRsend::sendBangOlufsen(uint16_t aHeader, uint8_t aData, int_fast8_t aNumberOfRepeats, int8_t aNumberOfHeaderBits) {

}

void IRsend::sendBangOlufsenDataLink(uint32_t aHeader, uint8_t aData, int_fast8_t aNumberOfRepeats, int8_t aNumberOfHeaderBits) {

}

/*

* @param aBackToBack If true send data back to back, which cannot be decoded if ENABLE_BEO_WITHOUT_FRAME_GAP is NOT defined

*/

void IRsend::sendBangOlufsenRaw(uint32_t aRawData, int_fast8_t aBits, bool aBackToBack) {

}

/*

* Version with 64 bit aRawData, which can send both timings, but costs more program memory

* @param aBackToBack If true send data back to back, which cannot be decoded if ENABLE_BEO_WITHOUT_FRAME_GAP is NOT defined

* @param aUseDatalinkTiming if false it does the same as sendBangOlufsenRaw()

*/

void IRsend::sendBangOlufsenRawDataLink(uint64_t aRawData, int_fast8_t aBits, bool aBackToBack, bool aUseDatalinkTiming) {

}

#define BEO_MATCH_DELTA (BEO_UNIT / 2 - MICROS_PER_TICK)

static bool matchBeoLength(uint16_t aMeasuredTicks, uint16_t aMatchValueMicros) {

const uint16_t tMeasuredMicros = aMeasuredTicks * MICROS_PER_TICK;

return aMatchValueMicros - BEO_MATCH_DELTA < tMeasuredMicros && tMeasuredMicros < aMatchValueMicros + BEO_MATCH_DELTA;

}

bool IRrecv::decodeBangOlufsen() {

#if defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

if (decodedIRData.rawlen != 6 && decodedIRData.rawlen < 36) { // 16 bits minimum

#else

if (decodedIRData.rawlen < 44) { // 16 bits minimum

#endif

return false;

}

#if defined(SUPPORT_BEO_DATALINK_TIMING_FOR_DECODE)

uint16_t protocolMarkLength = 0; // contains BEO_IR_MARK or BEO_DATALINK_MARK depending of 4. mark received

uint64_t tDecodedRawData = 0;

#else

uint32_t tDecodedRawData = 0;

#endif

uint8_t tLastDecodedBitValue = 0; // the last start bit is assumed to be zero

uint8_t tPulseNumber = 0;

uint8_t tBitNumber = 0;

BEO_TRACE_PRINT(F("Pre gap: "));

BEO_TRACE_PRINT(decodedIRData.initialGapTicks * 50);

BEO_TRACE_PRINT(F(" raw len: "));

BEO_TRACE_PRINTLN(decodedIRData.rawlen);

#if defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

/*

* Check if we have the AGC part of the first frame, i.e. start bit 1 and 2.

*/

if (decodedIRData.rawlen == 6) {

if ((matchMark(decodedIRData.rawDataPtr->rawbuf[3], BEO_IR_MARK)

|| matchMark(decodedIRData.rawDataPtr->rawbuf[3], BEO_DATALINK_MARK))

&& (matchSpace(decodedIRData.rawDataPtr->rawbuf[4], BEO_PULSE_LENGTH_ZERO - BEO_IR_MARK)

|| matchSpace(decodedIRData.rawDataPtr->rawbuf[4], BEO_PULSE_LENGTH_ZERO - BEO_DATALINK_MARK))) {

BEO_TRACE_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_TRACE_PRINTLN(F("B&O: AGC only part (start bits 1 + 2 of 4) detected"));

} else {

return false; // no B&O protocol

}

} else {

/*

* Check if leading gap is trailing bit of first frame

*/

if (!matchSpace(decodedIRData.initialGapTicks, BEO_PULSE_LENGTH_START_BIT)) {

BEO_TRACE_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_TRACE_PRINTLN(F(": Leading gap is wrong")); // Leading gap is trailing bit of first frame

return false; // no B&O protocol

}

if (matchMark(decodedIRData.rawDataPtr->rawbuf[1], BEO_IR_MARK)) {

# if defined(SUPPORT_BEO_DATALINK_TIMING_FOR_DECODE)

protocolMarkLength = BEO_IR_MARK;

} else if (matchMark(decodedIRData.rawDataPtr->rawbuf[1], BEO_DATALINK_MARK)) {

protocolMarkLength = BEO_DATALINK_MARK;

# endif

} else {

BEO_TRACE_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_TRACE_PRINTLN(F(": mark length is wrong"));

return false;

}

// skip first zero header bit

for (uint8_t tRawBufferMarkIndex = 3; tRawBufferMarkIndex < decodedIRData.rawlen; tRawBufferMarkIndex += 2) {

#else

for (uint8_t tRawBufferMarkIndex = 1; tRawBufferMarkIndex < decodedIRData.rawlen; tRawBufferMarkIndex += 2) {

#endif // defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

uint16_t markLength = decodedIRData.rawDataPtr->rawbuf[tRawBufferMarkIndex];

uint16_t spaceLength = decodedIRData.rawDataPtr->rawbuf[tRawBufferMarkIndex + 1];

BEO_TRACE_PRINT(tPulseNumber);

BEO_TRACE_PRINT(' ');

BEO_TRACE_PRINT(markLength * MICROS_PER_TICK);

BEO_TRACE_PRINT(' ');

BEO_TRACE_PRINT(spaceLength * MICROS_PER_TICK);

BEO_TRACE_PRINT(F(" ("));

BEO_TRACE_PRINT((markLength + spaceLength) * MICROS_PER_TICK);

BEO_TRACE_PRINTLN(F(") "));

#if !defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

/*

* Handle the first 4 start bits

* Check if the 3. bit is the long start bit. If we see the long start bit earlier, synchronize bit counter.

*/

if (tPulseNumber < 4) {

if (tPulseNumber < 2) {

// bit 0 and 1

if (matchSpace(spaceLength, BEO_PULSE_LENGTH_START_BIT - BEO_IR_MARK)) {

BEO_TRACE_PRINTLN(F(": detected long start bit -> synchronize state now"));

tPulseNumber = 2;

}

} else {

if (tPulseNumber == 3) {

if (matchMark(markLength, BEO_IR_MARK)) {

# if defined(SUPPORT_BEO_DATALINK_TIMING_FOR_DECODE)

protocolMarkLength = BEO_IR_MARK;

} else if (matchMark(markLength, BEO_DATALINK_MARK)) {

protocolMarkLength = BEO_DATALINK_MARK;

# endif

} else {

BEO_DEBUG_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_DEBUG_PRINTLN(F(": 4. (start) mark length is wrong"));

return false;

}

}

// bit 2 and 3

if (!matchBeoLength(markLength + spaceLength,

(tPulseNumber == 2) ? BEO_PULSE_LENGTH_START_BIT : BEO_PULSE_LENGTH_ZERO)) {

BEO_DEBUG_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_DEBUG_PRINTLN(F(": Start length is wrong"));

return false;

}

}

} else {

#endif // !defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

/*

* Decode header / data

* First check for length of mark

*/

#if defined(SUPPORT_BEO_DATALINK_TIMING_FOR_DECODE)

if (!matchMark(markLength, protocolMarkLength)) {

#else

if (!matchMark(markLength, BEO_IR_MARK)) {

#endif

BEO_DEBUG_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_DEBUG_PRINTLN(F(": Mark length is wrong"));

return false;

}

/*

* Check for stop after receiving at least 8 bits for data and 4 bits for header

*/

if (tBitNumber > BEO_DATA_BITS + 4) {

if (matchBeoLength(markLength + spaceLength, BEO_PULSE_LENGTH_TRAILING_BIT)) {

BEO_DEBUG_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_DEBUG_PRINTLN(F(": Trailing bit detected"));

break;

}

#if !defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

if (tRawBufferMarkIndex >= decodedIRData.rawlen - 3) { // (rawlen - 3) is index of trailing bit mark

BEO_DEBUG_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_DEBUG_PRINTLN(F(": End of buffer, but no trailing bit detected"));

return false;

}

#endif

}

/*

* Decode bit

*/

if (tLastDecodedBitValue == 0 && matchBeoLength(markLength + spaceLength, BEO_PULSE_LENGTH_ONE)) {

tLastDecodedBitValue = 1;

} else if (tLastDecodedBitValue == 1 && matchBeoLength(markLength + spaceLength, BEO_PULSE_LENGTH_ZERO)) {

tLastDecodedBitValue = 0;

} else if (!matchBeoLength(markLength + spaceLength, BEO_PULSE_LENGTH_EQUAL)) {

BEO_DEBUG_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_DEBUG_PRINT(F(": Index="));

BEO_DEBUG_PRINT(tRawBufferMarkIndex);

BEO_DEBUG_PRINT(F(" Length "));

BEO_DEBUG_PRINT((markLength + spaceLength) * MICROS_PER_TICK);

BEO_DEBUG_PRINTLN(F(" is wrong"));

return false;

}

tDecodedRawData <<= 1;

tDecodedRawData |= tLastDecodedBitValue;

++tBitNumber;

BEO_TRACE_PRINT(F("Bits "));

BEO_TRACE_PRINT(tBitNumber);

BEO_TRACE_PRINT(F(" "));

BEO_TRACE_PRINT(uint32_t(tDecodedRawData >> BEO_DATA_BITS), HEX);

BEO_TRACE_PRINT(F(" "));

BEO_TRACE_PRINTLN(uint8_t(tDecodedRawData & ((1 << BEO_DATA_BITS) - 1)), HEX);

// End of bit decode

#if !defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

}

#else

/*

* Check for last bit after decoding it

*/

if (tRawBufferMarkIndex >= decodedIRData.rawlen - 3) { // (rawlen - 3) is index of last bit mark

BEO_TRACE_PRINT(::getProtocolString(BANG_OLUFSEN));

BEO_TRACE_PRINTLN(F(": Last bit reached"));

break;

}

#endif

++tPulseNumber;

}

#if defined(ENABLE_BEO_WITHOUT_FRAME_GAP)

}

#endif

decodedIRData.protocol = BANG_OLUFSEN;

decodedIRData.address = tDecodedRawData >> BEO_DATA_BITS; // lower header tBitNumber

decodedIRData.command = tDecodedRawData & ((1 << BEO_DATA_BITS) - 1); // lower 8 tBitNumber

decodedIRData.extra = tDecodedRawData >> (BEO_DATA_BITS + 16); // upper header tBitNumber

decodedIRData.numberOfBits = tBitNumber;

decodedIRData.flags = IRDATA_FLAGS_IS_MSB_FIRST;

decodedIRData.decodedRawData = tDecodedRawData;

return true;

}

#endif // _IR_BANG_OLUFSEN_HPP