Several small fixes for modulated delay offset and amplitude calculation.

MicroMDAEPiano.ino

@@ -248,17 +248,23 @@ void setup()
   modulator.offset(0.0);
 #ifdef DEBUG
   Serial.print(F("Modulated delay buffer: "));
+  Serial.print(SAMPLES2TIME_MS(MOD_DELAY_SAMPLE_BUFFER), 2);
+  Serial.print(F(" ms / "));
   Serial.print(MOD_DELAY_SAMPLE_BUFFER, DEC);
   Serial.println(F(" samples"));
-  Serial.print(F("Default delay time: "));
-  Serial.print(float(ENC_CHORUS_DELAY_DEFAULT) / 10, 2);
-  Serial.println(" ms");
   Serial.print(F("Max delay time: "));
   Serial.print(float(ENC_CHORUS_DELAY_MAX) / 10, 2);
-  Serial.println(F(" ms"));
+  Serial.print(F(" ms / "));
+  Serial.print(uint16_t(TIME_MS2SAMPLES(float(ENC_CHORUS_DELAY_MAX) / 10)), DEC);
+  Serial.println(F(" samples"));
+  Serial.print(F("Default delay time: "));
+  Serial.print(float(ENC_CHORUS_DELAY_DEFAULT) / 10, 2);
+  Serial.print(F(" ms / "));
+  Serial.print(uint16_t(TIME_MS2SAMPLES(float(ENC_CHORUS_DELAY_DEFAULT) / 10)), DEC);
+  Serial.println(F(" samples"));
 #endif
-  modchorus_r.offset(TIME_MS2SAMPLES(float(ENC_CHORUS_DELAY_DEFAULT) / 10));
-  modchorus_l.offset(TIME_MS2SAMPLES(float(ENC_CHORUS_DELAY_DEFAULT) / 10));
+  modchorus_r.offset(TIME_MS2SAMPLES(float(ENC_CHORUS_DELAY_MAX) / 10));
+  modchorus_l.offset(TIME_MS2SAMPLES(float(ENC_CHORUS_DELAY_MAX) / 10));
   // Butterworth filter, 12 db/octave
   modchorus_filter_r.setLowpass(0, 6000, 0.707);
   modchorus_filter_l.setLowpass(0, 6000, 0.707);

UI.hpp

@@ -243,7 +243,7 @@ char* get_chorus_frequency_value_text(void)
 char chorus_delay_value_text1[] = "       ";
 char* get_chorus_delay_value_text(void)
 {
-  sprintf(chorus_delay_value_text1, "%02.1f ms", float(configuration.chorus_delay + ENC_CHORUS_DELAY_MAX) / 10);
+  sprintf(chorus_delay_value_text1, "%02.1f ms", float(configuration.chorus_delay) / 10);
 
   return (chorus_delay_value_text1);
 }

config.h

@@ -59,8 +59,8 @@
 #define USE_XFADE_DATA 1
 
 /* HELPER MACROS */
-#define TIME_MS2SAMPLES(x) floor(x * AUDIO_SAMPLE_RATE / 1000)
-#define SAMPLES2TIME_MS(x) float(x * 1000 / AUDIO_SAMPLE_RATE)
+#define TIME_MS2SAMPLES(x) floor(uint32_t(x) * AUDIO_SAMPLE_RATE / 1000)
+#define SAMPLES2TIME_MS(x) float(uint32_t(x) * 1000 / AUDIO_SAMPLE_RATE)
 // CHORUS parameters
 #define MOD_DELAY_SAMPLE_BUFFER int32_t(TIME_MS2SAMPLES(10.0))
 #define MOD_WAVEFORM WAVEFORM_TRIANGLE // WAVEFORM_SINE WAVEFORM_TRIANGLE WAVEFORM_SAWTOOTH WAVEFORM_SAWTOOTH_REVERSE
@@ -238,9 +238,9 @@
 #define ENC_CHORUS_FREQUENCY_MAX 200
 #define ENC_CHORUS_FREQUENCY_DEFAULT 30
 //
-#define ENC_CHORUS_DELAY_MIN 0
-#define ENC_CHORUS_DELAY_MAX uint8_t(SAMPLES2TIME_MS(float(MOD_DELAY_SAMPLE_BUFFER/2)*10))
-#define ENC_CHORUS_DELAY_DEFAULT uint8_t(float(ENC_CHORUS_DELAY_MAX/2))
+#define ENC_CHORUS_DELAY_MIN uint8_t(SAMPLES2TIME_MS(MOD_DELAY_SAMPLE_BUFFER>>2)*10+0.5)
+#define ENC_CHORUS_DELAY_MAX uint8_t(SAMPLES2TIME_MS(MOD_DELAY_SAMPLE_BUFFER>>2)*30+0.5)
+#define ENC_CHORUS_DELAY_DEFAULT uint8_t(SAMPLES2TIME_MS(MOD_DELAY_SAMPLE_BUFFER>>2)*20+0.5)
 //
 #define ENC_CHORUS_INTENSITY_MIN 0
 #define ENC_CHORUS_INTENSITY_MAX 100

effect_modulated_delay.cpp

@@ -29,8 +29,6 @@
 
 extern config_t configuration;
 
-#define MODULATION_MAX_FACTOR 0.5 // Not sure to put this into a var?
-
 /******************************************************************/
 
 // Based on;      A u d i o E f f e c t D e l a y
@@ -39,7 +37,7 @@ extern config_t configuration;
 // 140219 - correct storage class (not static)
 // 190527 - added modulation input (by Holger Wirtz)
 
-boolean AudioEffectModulatedDelay::begin(short *delayline, int d_length)
+boolean AudioEffectModulatedDelay::begin(short *delayline, uint16_t d_length)
 {
 #if 0
   Serial.print(F("AudioEffectModulatedDelay.begin(modulated-delay line length = "));
@@ -66,13 +64,18 @@ boolean AudioEffectModulatedDelay::begin(short *delayline, int d_length)
   return (true);
 }
 
-void AudioEffectModulatedDelay::offset(uint8_t offset_value) // in %
+void AudioEffectModulatedDelay::offset(uint16_t offset_value) // in %
 {
   if (offset_value > 100)
     offset_value = 100;
   _delay_offset = floor(offset_value / 200.0 * _delay_length);
 }
 
+uint16_t AudioEffectModulatedDelay::get_delay_length(void)
+{
+  return (_delay_length);
+}
+
 void AudioEffectModulatedDelay::update(void)
 {
   audio_block_t *block;
@@ -106,7 +109,7 @@ void AudioEffectModulatedDelay::update(void)
       _delayline[_cb_index] = *bp;
 
       // calculate the modulation-index as a floating point number for interpolation
-      mod_index = *mp * MODULATION_MAX_FACTOR * _delay_length;
+      mod_index = *mp * (_delay_length >> 2);
       mod_fraction = modff(mod_index, &mod_number); // split float of mod_index into integer (= mod_number) and fraction part
 
       // calculate modulation index into circular buffer

effect_modulated_delay.h

@@ -34,9 +34,6 @@
 // 140219 - correct storage class (not static)
 // 190527 - added modulation input handling (Aug 2019 by Holger Wirtz)
 
-#define TIME_MS2SAMPLES(x) floor(x * AUDIO_SAMPLE_RATE / 1000)
-#define SAMPLES2TIME_MS(x) float(x * 1000 / AUDIO_SAMPLE_RATE)
-
 class AudioEffectModulatedDelay :
   public AudioStream
 {
@@ -45,9 +42,10 @@ class AudioEffectModulatedDelay :
       AudioStream(2, inputQueueArray)
     { }
 
-    boolean begin(short *delayline, int delay_length);
+    boolean begin(short *delayline, uint16_t delay_length);
     virtual void update(void);
-    virtual void offset(uint8_t offset_value);
+    virtual void offset(uint16_t offset_value);
+    virtual uint16_t get_delay_length(void);
 
   private:
     void set_modulator_filter_coeffs(void);