Rework tone detector

- Send buffer pointers from ISR to userspace
- Use ADC interrupt to fetch data, not TIM6
- Increase size of buffer and do double-buffering
- Implement DTMF detectors
- Compare relative results instead of using absolute thresholds
- Add an IIR averaging filter on the results

2 files changed, 7 insertions, 7 deletions

diff --git a/src/common/includes/Audio/audio_in.h b/src/common/includes/Audio/audio_in.h
index 3bc543c..a543a69 100644
--- a/src/common/includes/Audio/audio_in.h
+++ b/src/common/includes/Audio/audio_in.h
@@ -28,10 +28,11 @@
 #include "FreeRTOS.h"
 
 #define AUDIO_IN_RATE 8000
-#define AUDIO_IN_BUF_LEN 32
+#define AUDIO_IN_BUF_LEN 400
 
-void audio_in_initialize(int rate);
+void audio_in_initialize(void);
 
-// Fill the buffer with AUDIO_IN_BUF_LEN samples.
-void audio_in_get_buffer(int16_t *buffer /*of length AUDIO_IN_BUF_LEN*/ );
+// After calling this function, *buffer will point to new audio data.
+// Returns the number of times filling the internal buffer failed.
+int32_t audio_in_get_buffer(int16_t **buffer /*of length AUDIO_IN_BUF_LEN*/ );
 
diff --git a/src/common/includes/Audio/tone.h b/src/common/includes/Audio/tone.h
index 861a472..b8a7f72 100644
--- a/src/common/includes/Audio/tone.h
+++ b/src/common/includes/Audio/tone.h
@@ -30,18 +30,17 @@
 
 #define TONE_BUFFER_LEN AUDIO_IN_BUF_LEN
 
-#define TONE_N 100
+#define TONE_N 400
 
 struct tone_detector {
     float coef;
     float Q1;
     float Q2;
-    float threshold;
 
     int num_samples_analysed;
 };
 
-void tone_init(int threshold);
+void tone_init(void);
 
 /* Return 1 when 1750 detected, 0 otherwise */
 int tone_1750_status(void);