[patch] Send IR with hw_audio
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[patch] Send IR with hw_audio
by Bob van Loosen-2
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
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Latest patch and documentation.Hi! Bob van Loosen bob.loosen@... wrote: [...] Bob. Index: configure.ac =================================================================== RCS file: /cvsroot/lirc/lirc/configure.ac,v retrieving revision 1.32 diff -u -r1.32 configure.ac --- configure.ac 13 Sep 2009 10:49:09 -0000 1.32 +++ configure.ac 30 Oct 2009 19:38:38 -0000 @@ -510,7 +510,7 @@ CFLAGS="$CFLAGS `${LIBUSB_CONFIG} --cflags`" ;; audio) - hw_module="${hw_module} hw_audio.o receive.o" + hw_module="${hw_module} hw_audio.o transmit.o receive.o" portaudio_lib="-lportaudio ${portaudio_lib_other}" ;; audio_alsa) @@ -777,7 +777,7 @@ if test "$driver" = "audio"; then lirc_driver="audio" - hw_module="hw_audio.o receive.o" + hw_module="hw_audio.o transmit.o receive.o" HW_DEFAULT="hw_audio" portaudio_lib="-lportaudio ${portaudio_lib_other}" fi Index: ./daemons/hw_audio.c =================================================================== RCS file: /cvsroot/lirc/lirc/daemons/hw_audio.c,v retrieving revision 5.6 diff -u -r5.6 hw_audio.c --- ./daemons/hw_audio.c 28 Oct 2009 19:20:41 -0000 5.6 +++ ./daemons/hw_audio.c 30 Oct 2009 19:38:38 -0000 @@ -49,9 +49,11 @@ /* PortAudio Includes */ #include <portaudio.h> -#define SAMPLE_RATE (44100) -#define NUM_CHANNELS (2) -#define DITHER_FLAG (0) /**/ +#define SAMPLE_RATE (48000) +#define NUM_CHANNELS (2) +#define DITHER_FLAG (0) /**/ +#define CARRIER (18000) +#define PI (3.141592654) /* Select sample format. */ #define PA_SAMPLE_TYPE paUInt8 @@ -63,6 +65,11 @@ int lastSign; int pulseSign; unsigned int lastCount; + double carrierPos; /* position the sine generator is in */ + double remainingSignal; /* length of the remaining signal is stored here when the callback exits */ + int signalPhase; /* 1 = pulse, 0 = space */ + int signaledDone; + int samplesToIgnore; } paTestData; @@ -74,7 +81,9 @@ char ptyName[256]; int master; - +int sendPipe[2]; /* signals are written from audio_send and read from the callback */ +int completedPipe[2]; /* a byte is written here when the callback has processed all signals */ +int outputLatency; int myfd = -1; @@ -96,7 +105,7 @@ { paTestData *data = (paTestData*)userData; SAMPLE *rptr = (SAMPLE*)inputBuffer; - long i; + long i, j; SAMPLE *myPtr = rptr; @@ -104,11 +113,23 @@ int samplerate = SAMPLE_RATE; int diff; - (void) outputBuffer; /* Prevent unused variable warnings. */ + SAMPLE* outptr = (SAMPLE*)outputBuffer; + int out; + double currentSignal = data->remainingSignal; + lirc_t signal; + + /* Prevent unused variable warnings. */ (void) outTime; for ( i=0; i < framesPerBuffer; i++, myPtr++) { + /* check if we have to ignore this sample */ + if (data->samplesToIgnore) + { + *myPtr = 128; + data->samplesToIgnore--; + } + /* New Algo */ diff = abs(data->lastFrames[0] - *myPtr); if ( diff > 100) @@ -179,6 +200,65 @@ if (NUM_CHANNELS == 2) myPtr++; } + + /* generate output */ + for (i = 0; i < framesPerBuffer; i++) + { + if (currentSignal <= 0.0) /* last signal we sent went out */ + { + if (read(sendPipe[0], &signal, sizeof(signal)) > 0) /* try to read a new signal, non blocking */ + { + currentSignal += signal; /* when a new signal is read, add it */ + data->signalPhase = data->signalPhase ? 0 : 1; /* invert the phase */ + data->signaledDone = 0; + + /* when transmitting, ignore input samples for one second */ + data->samplesToIgnore = SAMPLE_RATE; + } + else + { + data->signalPhase = 0; /* no more signals, reset phase */ + if (!data->signaledDone) /* signal that we have written all signals */ + { + char done = 0; + data->signaledDone = 1; + write(completedPipe[1], &done, sizeof(done)); + } + } + } + + if (currentSignal > 0.0) + { + if (data->signalPhase) /* write carrier */ + out = rint(sin(data->carrierPos / (180.0 / PI)) * 127.0 + 128.0); + else + out = 128; + + /* one channel is inverted, so both channels can be used to double the voltage */ + *outptr++ = out; + if (NUM_CHANNELS == 2) + *outptr++ = 256 - out; + + /* subtract how much of the current signal was sent */ + currentSignal -= 1000000.0 / SAMPLE_RATE; + } + else + { + *outptr++ = 128; + if (NUM_CHANNELS == 2) + *outptr++ = 128; + } + + /* increase carrier position */ + data->carrierPos += (double)CARRIER / SAMPLE_RATE * 360.0; + + if (data->carrierPos >= 360.0) + data->carrierPos -= 360.0; + } + + /* save how much we still have to write */ + data->remainingSignal = currentSignal; + return 0; } @@ -209,6 +289,48 @@ return(data); } +static int audio_send(struct ir_remote *remote,struct ir_ncode *code) +{ + int length; + lirc_t* signals; + int flags; + char completed; + + if(!init_send(remote, code)) + return 0; + + length = send_buffer.wptr; + signals = send_buffer.data; + + if (length <= 0 || signals == NULL) + { + LOGPRINTF(1, "nothing to send"); + return 0; + } + + /* set completed pipe to non blocking */ + flags = fcntl(completedPipe[0], F_GETFL, 0); + fcntl(completedPipe[0], F_SETFL, flags | O_NONBLOCK); + + /* remove any unwanted completed bytes */ + while (read(completedPipe[0], &completed, sizeof(completed)) == 1); + + /* set completed pipe to blocking */ + fcntl(completedPipe[0], F_SETFL, flags & ~O_NONBLOCK); + + /* write signals to sendpipe */ + if (write(sendPipe[1], signals, length * sizeof(lirc_t)) == -1) + { + logprintf(LOG_ERR,"write failed"); + logperror(LOG_ERR,"write()"); + return 0; + } + + /* wait for the callback to signal us that all signals are written */ + read(completedPipe[0], &completed, sizeof(completed)); + + return 1; +} /* interface functions @@ -219,6 +341,7 @@ { PaStreamParameters inputParameters; + PaStreamParameters outputParameters; PaError err; int flags; struct termios t; @@ -237,6 +360,11 @@ data.lastSign = 0; data.lastCount = 0; data.pulseSign = 0; + data.carrierPos = 0.0; + data.remainingSignal = 0.0; + data.signalPhase = 0; + data.signaledDone = 1; + data.samplesToIgnore = 0; err = Pa_Initialize(); if( err != paNoError ) goto error; @@ -252,16 +380,28 @@ Pa_GetDeviceInfo( inputParameters.device )->defaultLowInputLatency; inputParameters.hostApiSpecificStreamInfo = NULL; + outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */ + if (outputParameters.device == paNoDevice) { + logprintf(LOG_ERR, "No default output device"); + goto error; + } + outputParameters.channelCount = NUM_CHANNELS; /* stereo output */ + outputParameters.sampleFormat = PA_SAMPLE_TYPE; + outputParameters.suggestedLatency = + Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency; + outputParameters.hostApiSpecificStreamInfo = NULL; + + outputLatency = outputParameters.suggestedLatency * 1000000; // Record some audio. -------------------------------------------- err = Pa_OpenStream ( &stream, &inputParameters, - NULL, // output parameters + &outputParameters, SAMPLE_RATE, 512, // frames per buffer - 0, // flags + paPrimeOutputBuffersUsingStreamCallback, recordCallback, &data ); @@ -299,6 +439,26 @@ hw.fd=ptyfd; + /* make a pipe for sending signals to the callback */ + /* make a pipe for signaling from the callback that everything was sent */ + if (pipe(sendPipe) == -1 || pipe(completedPipe) == -1) + { + logprintf(LOG_ERR,"pipe failed"); + logperror(LOG_ERR,"pipe()"); + } + + /* make the readable end non-blocking */ + flags = fcntl(sendPipe[0], F_GETFL, 0); + if(flags != -1) + { + fcntl(sendPipe[0], F_SETFL, flags | O_NONBLOCK); + } + else + { + logprintf(LOG_ERR,"fcntl failed"); + logperror(LOG_ERR,"fcntl()"); + } + err = Pa_StartStream( stream ); if( err != paNoError ) goto error; @@ -319,6 +479,11 @@ LOGPRINTF(1,"hw_audio_deinit()"); + /* make absolutely sure the full output buffer has played out + even though portaudio should wait for it, it doesn't always happen */ + sleep(outputLatency / 1000000); + usleep(outputLatency % 1000000); + // close port audio err = Pa_CloseStream( stream ); if( err != paNoError ) goto error; @@ -332,6 +497,11 @@ close(master); close(ptyfd); + close(sendPipe[0]); + close(sendPipe[1]); + close(completedPipe[0]); + close(completedPipe[1]); + return 1; error: @@ -353,14 +523,14 @@ { "pty", /* simple device */ -1, /* fd */ - LIRC_CAN_REC_MODE2, /* features */ - 0, /* send_mode */ + LIRC_CAN_REC_MODE2 | LIRC_CAN_SEND_PULSE, /* features */ + LIRC_MODE_PULSE, /* send_mode */ LIRC_MODE_MODE2, /* rec_mode */ 0, /* code_length */ audio_init, /* init_func */ NULL, /* config_func */ audio_deinit, /* deinit_func */ - NULL, /* send_func */ + audio_send, /* send_func */ audio_rec, /* rec_func */ receive_decode, /* decode_func */ NULL, /* ioctl_func */ Using the audio driver for transmitting. Pros: Very simple circuit. No need for a kernel module. Cons: Doesn't transmit very far without an amplifier (about 3 meters when directly aiming). A reasonably good soundcard is required (cheap cards might not provide enough voltage, or might not be able to output a correct 18 kHz sine). How it works: The audio driver can send IR signals using a (reasonably good) soundcard and a very simple circuit. It does this by outputting a 18 kHz sine, which after rectification becomes a 36 kHz carrier wave. The wave is inverted on the right channel, so the left and right channels can be used to double the voltage. 
The top wave is how the wave looks when it comes out the soundcard, the bottom wave is how it looks after rectification, as you can see the frequency is doubled. The rectification is done using the following circuit:  LED1 and LED2 are 950nm infrared leds, R1 is a 0.25 watt resistor. Because leds are diodes, they only conduct one way. Since the soundcard outputs a wave that goes both positive and negative, two leds are placed antiparallel, that way infrared is emitted on both the positive and negative cycles. R1 is used to limit the current, this presents a load to the soundcard that is roughly the same as a pair of 32 ohms headphones. To make the transmission more powerful, you can try lowering the value of R1 (or just short it out), but this might damage your soundcard, the leds, or both. So try at your own risk! Another way to make the transmission more powerful is to use a small speaker amplifier (5 watts or less), in this case a 5 watt resistor should be used for safety. The volume should be adjusted so that the amplifier outputs its full voltage without clipping. Setting up: Compile lirc with the audio driver (not the IR diode or alsa ones) and install it as usual. Connect the circuit to the soundcard and set the volume to the maximum level. Use irsend to test if it works. Known issues: The audio driver uses portaudio to interface with the soundcard, there seems to be a bug in some later versions that makes portaudio hang completely, lircd becomes unresponsive and you have to kill it with killall -9 lircd. To get around this use the portaudio stable release from December 7, 2007. ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference |
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
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Re: [patch] Send IR with hw_audio
by Ryan Voots
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
::
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
::
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
::
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
::
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
::
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
::
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
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Re: [patch] Send IR with hw_audio
by Bob van Loosen-2
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Attached updated documentation. Bob. Using the audio driver for transmitting. Pros: Very simple circuit. No need for a kernel module. Cons: Doesn't transmit very far without an amplifier (about 3 meters when directly aiming). A reasonably good soundcard is required (cheap cards might not provide enough voltage, or might not be able to output a correct 18 kHz sine). It takes some time to set up (50 ms or so) so when no clients are connected to lircd the first transmission will have some higher latency. A workaround for this is to keep irw running with a bash script like this:
#!/bin/bash
How it works: The audio driver can send IR signals using a (reasonably good) soundcard and a very simple circuit. It does this by outputting a 18 kHz sine, which after rectification becomes a 36 kHz carrier wave. The wave is inverted on the right channel, so the left and right channels can be used to double the voltage.
The top wave is how the wave looks when it comes out the soundcard, the bottom wave is how it looks after rectification, as you can see the frequency is doubled. The rectification is done using the following circuit: LED1 and LED2 are 950nm infrared leds, R1 is a 0.25 watt resistor. Because leds are diodes, they only conduct one way. Since the soundcard outputs a wave that goes both positive and negative, two leds are placed antiparallel, that way infrared is emitted on both the positive and negative cycles. R1 is used to limit the current, this presents a load to the soundcard that is roughly the same as a pair of 32 ohms headphones. To make the transmission more powerful, you can try lowering the value of R1 (or just short it out), but this might damage your soundcard, the leds, or both. So try at your own risk! Another way to make the transmission more powerful is to use a small speaker amplifier (5 watts or less), in this case a 5 watt resistor should be used for safety. The volume should be adjusted so that the amplifier outputs its full voltage without clipping. Setting up: Compile lirc with the audio driver (not the IR diode or alsa ones) and install it as usual. Connect the circuit to the soundcard and set the volume to the maximum level. Start lircd, the -d flag can be used to select the audio device and/or samplerate, the syntax is api:device[@samplerate] or @samplerate. Examples:
lircd -d ALSA:default
Use irsend to test if it works. Known issues: The audio driver uses portaudio to interface with the soundcard, there seems to be a bug in some later versions that makes portaudio hang completely, lircd becomes unresponsive and you have to kill it with killall -9 lircd. To get around this use the portaudio stable release from December 7, 2007. ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july |
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Re: [patch] Send IR with hw_audio
by Christoph Bartelmus
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