From 6d8fee68f48d728eebc139e9430a78085474a336 Mon Sep 17 00:00:00 2001
From: Gerolf Ziegenhain <g@ziegenhain.com>
Date: Mon, 3 Oct 2016 16:02:17 +0200
Subject: [PATCH] example

---
 src/buzzer.c | 178 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/irmc.c   |   4 +-
 2 files changed, 180 insertions(+), 2 deletions(-)
 create mode 100644 src/buzzer.c

diff --git a/src/buzzer.c b/src/buzzer.c
new file mode 100644
index 0000000..5077654
--- /dev/null
+++ b/src/buzzer.c
@@ -0,0 +1,178 @@
+#include "portaudio.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <unistd.h> // for usleep()
+
+#define SAMPLE_RATE   (44100)
+#define FRAMES_PER_BUFFER  (64)
+
+typedef struct
+{
+    uint32_t total_count;
+    uint32_t up_count;
+
+    uint32_t counter;
+    uint32_t prev_freq;
+    uint32_t freq;
+} paTestData;
+
+//volatile int freq = 0;
+
+/* This routine will be called by the PortAudio engine when audio is needed.
+** It may called at interrupt level on some machines so don't do anything
+** that could mess up the system like calling malloc() or free().
+*/
+static int patestCallback( const void *inputBuffer, void *outputBuffer,
+                           unsigned long framesPerBuffer,
+                           const PaStreamCallbackTimeInfo* timeInfo,
+                           PaStreamCallbackFlags statusFlags,
+                           void *userData )
+{
+    paTestData *data = (paTestData*)userData;
+    uint8_t *out = (uint8_t*)outputBuffer;
+    unsigned long i;
+    uint32_t freq = data->freq;
+
+    (void) timeInfo; /* Prevent unused variable warnings. */
+    (void) statusFlags;
+    (void) inputBuffer;
+
+    for( i=0; i<framesPerBuffer; i++ )
+    {
+        if(data->up_count > 0 && data->total_count == data->up_count) {
+            *out++ = 0x00;
+            continue;
+        }
+        data->total_count++;
+
+        if(freq != data->prev_freq) {
+            data->counter = 0;
+        }
+
+        if(freq) {
+            int overflow_max = SAMPLE_RATE / freq;
+            uint32_t data_cnt = data->counter % overflow_max;
+            if(data_cnt > overflow_max/2)
+                *out++ = 0xff;
+            else {
+                *out++ = 0x00;
+            }
+            data->counter++;
+        }
+        else {
+            data->counter = 0;
+            *out++ = 0;
+        }
+        data->prev_freq = freq;
+    }
+
+    return paContinue;
+}
+
+static PaStream *stream;
+static paTestData data;
+
+
+void buzzer_set_freq(int frequency)
+{
+    data.up_count = 0; // do not stop!
+    data.freq = frequency;
+}
+
+void buzzer_beep(int frequency, int msecs)
+{
+    data.total_count = 0;
+    data.up_count = SAMPLE_RATE * msecs / 1000;
+    data.freq = frequency;
+}
+
+int buzzer_start(void)
+{
+    PaStreamParameters outputParameters;
+
+    PaError err;
+    int i;
+
+    err = Pa_Initialize();
+    if( err != paNoError ) goto error;
+
+    outputParameters.device = Pa_GetDefaultOutputDevice(); /* default output device */
+    outputParameters.channelCount = 1;       /* stereo output */
+    outputParameters.sampleFormat = paUInt8; /* 32 bit floating point output */
+    outputParameters.suggestedLatency = Pa_GetDeviceInfo( outputParameters.device )->defaultLowOutputLatency;
+    outputParameters.hostApiSpecificStreamInfo = NULL;
+
+    err = Pa_OpenStream(
+        &stream,
+        NULL, /* no input */
+        &outputParameters,
+        SAMPLE_RATE,
+        FRAMES_PER_BUFFER,
+        paClipOff,      /* we won't output out of range samples so don't bother clipping them */
+        patestCallback,
+        &data );
+    if( err != paNoError ) goto error;
+
+    err = Pa_StartStream( stream );
+    if( err != paNoError ) goto error;
+
+    return err;
+error:
+    Pa_Terminate();
+    fprintf( stderr, "An error occured while using the portaudio stream\n" );
+    fprintf( stderr, "Error number: %d\n", err );
+    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
+    return err;
+
+}
+
+int buzzer_stop() 
+{
+    PaError err = 0;
+    err = Pa_StopStream( stream );
+    if( err != paNoError ) goto error;
+
+    err = Pa_CloseStream( stream );
+    if( err != paNoError ) goto error;
+
+    Pa_Terminate();
+
+    return err;
+error:
+    Pa_Terminate();
+    fprintf( stderr, "An error occured while using the portaudio stream\n" );
+    fprintf( stderr, "Error number: %d\n", err );
+    fprintf( stderr, "Error message: %s\n", Pa_GetErrorText( err ) );
+    return err;
+}
+void msleep(int d){
+    usleep(d*1000);
+}
+int main(void)
+{
+
+    // notes frequency chart: http://www.phy.mtu.edu/~suits/notefreqs.html
+
+    buzzer_start();
+    buzzer_set_freq(261);
+    msleep(250);
+    buzzer_set_freq(0);
+    msleep(250);
+    buzzer_set_freq(329);
+    msleep(250);
+    buzzer_set_freq(349);
+    msleep(250);
+    buzzer_set_freq(392);
+    msleep(250);
+    buzzer_set_freq(440);
+    msleep(250);
+    buzzer_set_freq(494);
+    msleep(250);
+    buzzer_beep(523, 200);
+    msleep(250);
+
+    buzzer_stop();
+
+    return 0;
+}
diff --git a/src/irmc.c b/src/irmc.c
index 24877cc..fafd333 100644
--- a/src/irmc.c
+++ b/src/irmc.c
@@ -353,11 +353,11 @@ int main(int argc, char *argv[])
 							else
 							{
 								if(length < 0) {
-									beep(0.0, abs(length)/1000.);
+									//beep(0.0, abs(length)/1000.);
 								}
 								else
 								{
-									beep(1000.0, length/1000.);
+									//beep(1000.0, length/1000.);
 								}
 							}
 						}