From 0ba699511c136e0215fd2f75e2800be920221497 Mon Sep 17 00:00:00 2001
From: "Matthias P. Braendli" <matthias.braendli@mpb.li>
Date: Thu, 11 Apr 2019 22:53:00 +0200
Subject: 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
---
 src/common/includes/Audio/tone.h | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

(limited to 'src/common/includes/Audio/tone.h')

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);
-- 
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