Added Expansion demo for SOS, DmaSPi is now internal

examples/Delay/AnalogDelayDemoExpansion/AnalogDelayDemoExpansion.ino

@@ -1,11 +1,22 @@
-#include <MIDI.h>
-
-#define TGA_PRO_REVB
-#define TGA_PRO_EXPAND_REV2
+/*************************************************************************
+ * This demo uses the BAGuitar library to provide enhanced control of
+ * the TGA Pro board.
+ * 
+ * The latest copy of the BA Guitar library can be obtained from
+ * https://github.com/Blackaddr/BAGuitar
+ * 
+ * This demo combines the Blackaddr Audio Expansion board to add physical controls
+ * to the BAAudioEffectAnalogDelay.
+ * 
+ * You can control the amount of delay, feedback and mix in realtime, as well as cycle
+ * through the various analog filters built into the effect.
+ * 
+ */
+#define TGA_PRO_REVB // Set which hardware revision of the TGA Pro we're using
+#define TGA_PRO_EXPAND_REV2 // pull in the pin definitions for the Blackaddr Audio Expansion Board.
 
 #include "BAGuitar.h"
 
-using namespace midi;
 using namespace BAEffects;
 using namespace BALibrary;
 
@@ -16,7 +27,7 @@ BAAudioControlWM8731 codec;
 //#define USE_EXT // uncomment this line to use External MEM0
 
 #ifdef USE_EXT
-// If using external SPI memory, we will instantiance an SRAM
+// If using external SPI memory, we will instantiate a SRAM
 // manager and create an external memory slot to use as the memory
 // for our audio delay
 ExternalSramManager externalSram;
@@ -42,30 +53,60 @@ AudioConnection delayOut(analogDelay, 0, cabFilter, 0);
 AudioConnection leftOut(cabFilter,0, i2sOut, 0);
 AudioConnection rightOut(cabFilter,0, i2sOut, 1);
 
+
 //////////////////////////////////////////
 // SETUP PHYSICAL CONTROLS
+// - POT1 (left) will control the amount of delay
+// - POT2 (right) will control the amount of feedback
+// - POT3 (centre) will control the wet/dry mix.
+// - SW1  (left) will be used as a bypass control
+// - LED1 (left) will be illuminated when the effect is ON (not bypass)
+// - SW2  (right) will be used to cycle through the three built in analog filter styles available.
+// - LED2 (right) will illuminate when pressing SW2.
 //////////////////////////////////////////
-BAPhysicalControls controls(BA_EXPAND_NUM_SW, BA_EXPAND_NUM_POT, 0);
+// To get the calibration values for your particular board, first run the
+// BAExpansionCalibrate.ino example and 
+constexpr int  potCalibMin = 1;
+constexpr int  potCalibMax = 1018;
+constexpr bool potSwapDirection = true;
+
+// Create a control object using the number of switches, pots, encoders and outputs on the
+// Blackaddr Audio Expansion Board.
+BAPhysicalControls controls(BA_EXPAND_NUM_SW, BA_EXPAND_NUM_POT, BA_EXPAND_NUM_ENC, BA_EXPAND_NUM_LED);
 
 int loopCount = 0;
+unsigned filterIndex = 0; // variable for storing which analog filter we're currently using.
+constexpr unsigned MAX_HEADPHONE_VOL = 10;
+unsigned headphoneVolume = MAX_HEADPHONE_VOL; // control headphone volume from 0 to 10.
+
+// BAPhysicalControls returns a handle when you register a new control. We'll uses these handles when working with the controls.
+int bypassHandle, filterHandle, delayHandle, feedbackHandle, mixHandle, led1Handle, led2Handle; // Handles for the various controls
 
 void setup() {
-  delay(100);
+  delay(100); // wait a bit for serial to be available
   Serial.begin(57600); // Start the serial port
   delay(100);
 
-  // Setup the controls
-  controls.addSwitch(BA_EXPAND_SW1_PIN);
-  controls.addSwitch(BA_EXPAND_SW2_PIN);
-  controls.addPot(BA_EXPAND_POT1_PIN, 
-
-  // Disable the codec first
+  // Setup the controls. The return value is the handle to use when checking for control changes, etc.
+  // pushbuttons
+  bypassHandle = controls.addSwitch(BA_EXPAND_SW1_PIN); // will be used for bypass control
+  filterHandle = controls.addSwitch(BA_EXPAND_SW2_PIN); // will be used for stepping through filters
+  // pots
+  delayHandle    = controls.addPot(BA_EXPAND_POT1_PIN, potCalibMin, potCalibMax, potSwapDirection); // control the amount of delay
+  feedbackHandle = controls.addPot(BA_EXPAND_POT2_PIN, potCalibMin, potCalibMax, potSwapDirection); 
+  mixHandle      = controls.addPot(BA_EXPAND_POT3_PIN, potCalibMin, potCalibMax, potSwapDirection); 
+  // leds
+  led1Handle = controls.addOutput(BA_EXPAND_LED1_PIN);
+  led2Handle = controls.addOutput(BA_EXPAND_LED2_PIN); // will illuminate when pressing SW2
+
+  // Disable the audio codec first
   codec.disable();
   AudioMemory(128);
 
-  // Enable the codec
+  // Enable and configure the codec
   Serial.println("Enabling codec...\n");
   codec.enable();
+  codec.setHeadphoneVolume(1.0f); // Max headphone volume
 
   // If using external memory request request memory from the manager
   // for the slot
@@ -77,8 +118,8 @@ void setup() {
   Serial.println("Using INTERNAL memory");
   #endif
 
-  // Besure to enable the delay. When disabled, audio is is completely blocked
-  // to minimize resources to nearly zero.
+  // Besure to enable the delay. When disabled, audio is is completely blocked by the effect
+  // to minimize resource usage to nearly to nearly zero.
   analogDelay.enable(); 
 
   // Set some default values.
@@ -89,18 +130,79 @@ void setup() {
 
   //////////////////////////////////
   // AnalogDelay filter selection //
-  // Uncomment to tryout the 3 different built-in filters.
+  // These are commented out, in this example we'll use SW2 to cycle through the different filters
   //analogDelay.setFilter(AudioEffectAnalogDelay::Filter::DM3); // The default filter. Naturally bright echo (highs stay, lows fade away)
   //analogDelay.setFilter(AudioEffectAnalogDelay::Filter::WARM); // A warm filter with a smooth frequency rolloff above 2Khz
   //analogDelay.setFilter(AudioEffectAnalogDelay::Filter::DARK); // A very dark filter, with a sharp rolloff above 1Khz
 
-  // Setup 2-stages of LPF, cutoff 4500 Hz, Q-factor 0.7071 (a 'normal' Q-factor)
+  // Guitar cabinet: Setup 2-stages of LPF, cutoff 4500 Hz, Q-factor 0.7071 (a 'normal' Q-factor)
   cabFilter.setLowpass(0, 4500, .7071);
   cabFilter.setLowpass(1, 4500, .7071);
 }
 
 void loop() {
 
+  float potValue;
+
+  // Check if SW1 has been toggled (pushed)
+  if (controls.isSwitchToggled(bypassHandle)) {
+    bool bypass = analogDelay.isBypass(); // get the current state
+    bypass = !bypass; // change it
+    analogDelay.bypass(bypass); // set the new state
+    controls.setOutput(led1Handle, !bypass); // Set the LED when NOT bypassed  
+    Serial.println(String("BYPASS is ") + bypass);
+  }
+
+  // Use SW2 to cycle through the filters
+  controls.setOutput(led2Handle, controls.getSwitchValue(led2Handle));
+  if (controls.isSwitchToggled(filterHandle)) {
+    filterIndex = (filterIndex + 1) % 3; // update and potentionall roll the counter 0, 1, 2, 0, 1, 2, ...
+    // cast the index between 0 to 2 to the enum class AudioEffectAnalogDelay::Filter
+    analogDelay.setFilter(static_cast<AudioEffectAnalogDelay::Filter>(filterIndex)); // will cycle through 0 to 2
+    Serial.println(String("Filter set to ") + filterIndex);
+  }
+
+  // Use POT1 (left) to control the delay setting
+  if (controls.checkPotValue(delayHandle, potValue)) {
+    // Pot has changed
+    Serial.println(String("New DELAY setting: ") + potValue);
+    analogDelay.delayFractionMax(potValue);
+  }
+
+  // Use POT2 (right) to control the feedback setting
+  if (controls.checkPotValue(feedbackHandle, potValue)) {
+    // Pot has changed
+    Serial.println(String("New FEEDBACK setting: ") + potValue);
+    analogDelay.feedback(potValue);
+  }
+
+  // Use POT3 (centre) to control the mix setting
+  if (controls.checkPotValue(mixHandle, potValue)) {
+    // Pot has changed
+    Serial.println(String("New MIX setting: ") + potValue);
+    analogDelay.mix(potValue);
+  }
+
+  // Use the 'u' and 'd' keys to adjust volume across ten levels.
+  if (Serial) {
+    if (Serial.available() > 0) {
+      while (Serial.available()) {
+        char key = Serial.read();
+        if (key == 'u') { 
+          headphoneVolume = (headphoneVolume + 1) % MAX_HEADPHONE_VOL;
+          Serial.println(String("Increasing HEADPHONE volume to ") + headphoneVolume);
+        }
+        else if (key == 'd') { 
+          headphoneVolume = (headphoneVolume - 1) % MAX_HEADPHONE_VOL;
+          Serial.println(String("Decreasing HEADPHONE volume to ") + headphoneVolume);
+        }
+        codec.setHeadphoneVolume(static_cast<float>(headphoneVolume) / static_cast<float>(MAX_HEADPHONE_VOL));
+      }
+    }
+  }
+
+  // Use the loopCounter to roughly measure human timescales. Every few seconds, print the CPU usage
+  // to the serial port. About 500,000 loops!
   if (loopCount % 524288 == 0) {
     Serial.print("Processor Usage, Total: "); Serial.print(AudioProcessorUsage());
     Serial.print("% ");
@@ -109,5 +211,4 @@ void loop() {
   }
   loopCount++;
 
-
 }

examples/Delay/SoundOnSoundExpansionDemo/SoundOnSoundExpansionDemo.ino

@@ -0,0 +1,219 @@
+/*************************************************************************
+ * This demo uses the BAGuitar library to provide enhanced control of
+ * the TGA Pro board.
+ * 
+ * The latest copy of the BA Guitar library can be obtained from
+ * https://github.com/Blackaddr/BAGuitar
+ * 
+ * THIS DEMO REQUIRES BOTH THE EXTERNAL SRAM AND EXPANSION BOARD ADD-ONS
+ * 
+ * This demo combines the Blackaddr Audio Expansion board with the BAAudioEffectSOS,
+ * which provides sound-on-sound. The pushbuttons control the opening of the effect 
+ * gate, as well as clearing the sound being held.
+ * 
+ * The pots control the feedback, as well as the gate opening and close times.
+ * 
+ */
+#define TGA_PRO_REVB // Set which hardware revision of the TGA Pro we're using
+#define TGA_PRO_EXPAND_REV2 // pull in the pin definitions for the Blackaddr Audio Expansion Board.
+
+#include "BAGuitar.h"
+
+using namespace BAEffects;
+using namespace BALibrary;
+
+AudioInputI2S i2sIn;
+AudioOutputI2S i2sOut;
+BAAudioControlWM8731 codec;
+
+// External SRAM is required for this effect due to the very long
+// delays required.
+ExternalSramManager externalSram;
+ExtMemSlot delaySlot; // Declare an external memory slot.
+
+AudioEffectSOS sos(&delaySlot);
+
+// Add some effects for our soloing channel
+AudioEffectDelay         delayModule; // we'll add a little slapback echo
+AudioMixer4              gainModule; // This will be used simply to reduce the gain before the reverb
+AudioEffectReverb        reverb; // Add a bit of 'verb to our tone
+AudioFilterBiquad        cabFilter; // We'll want something to cut out the highs and smooth the tone, just like a guitar cab.
+AudioMixer4 mixer;
+
+// Connect the input
+AudioConnection inputToSos(i2sIn, 0, sos, 0);
+AudioConnection inputToSolo(i2sIn, 0, delayModule, 0);
+
+// Patch cables for the SOLO channel
+AudioConnection inputToGain(delayModule, 0, gainModule, 0);
+AudioConnection inputToReverb(gainModule, 0, reverb, 0);
+
+// Output Mixer
+AudioConnection mixer0input(i2sIn, 0, mixer, 0);  // SOLO Dry Channel
+AudioConnection mixer1input(reverb, 0, mixer, 1); // SOLO Wet Channel
+AudioConnection mixer2input(sos, 0, mixer, 2); // SOS Channel
+AudioConnection inputToCab(mixer, 0, cabFilter, 0);
+
+// CODEC Outputs
+AudioConnection outputLeft(cabFilter, 0, i2sOut, 0);
+AudioConnection outputRight(cabFilter, 0, i2sOut, 1);
+
+//////////////////////////////////////////
+// SETUP PHYSICAL CONTROLS
+// - POT1 (left) will control the GATE OPEN time
+// - POT2 (right) will control the GATE CLOSE TIME
+// - POT3 (centre) will control the EFFECT VOLUME
+// - SW1  (left) will be used as the GATE TRIGGER
+// - LED1 (left) will be illuminated while the GATE is open
+// - SW2  (right) will be used as the CLEAR FEEDBACK TRIGGER
+// - LED2 (right) will illuminate when pressing SW2.
+//////////////////////////////////////////
+// To get the calibration values for your particular board, first run the
+// BAExpansionCalibrate.ino example and 
+constexpr int  potCalibMin = 1;
+constexpr int  potCalibMax = 1018;
+constexpr bool potSwapDirection = true;
+
+// Create a control object using the number of switches, pots, encoders and outputs on the
+// Blackaddr Audio Expansion Board.
+BAPhysicalControls controls(BA_EXPAND_NUM_SW, BA_EXPAND_NUM_POT, BA_EXPAND_NUM_ENC, BA_EXPAND_NUM_LED);
+
+int loopCount = 0;
+constexpr unsigned MAX_HEADPHONE_VOL = 10;
+unsigned headphoneVolume = MAX_HEADPHONE_VOL; // control headphone volume from 0 to 10.
+constexpr float MAX_GATE_TIME_MS = 4000.0f; // set maximum gate time of 4 seconds.
+
+// BAPhysicalControls returns a handle when you register a new control. We'll uses these handles when working with the controls.
+int gateHandle, clearHandle, openHandle, closeHandle, volumeHandle, led1Handle, led2Handle; // Handles for the various controls
+
+
+void setup() {
+
+delay(100);
+  delay(100); // wait a bit for serial to be available
+  Serial.begin(57600); // Start the serial port
+  delay(100); // wait a bit for serial to be available
+
+  // Setup the controls. The return value is the handle to use when checking for control changes, etc.
+  // pushbuttons
+  gateHandle  = controls.addSwitch(BA_EXPAND_SW1_PIN); // will be used for bypass control
+  clearHandle = controls.addSwitch(BA_EXPAND_SW2_PIN); // will be used for stepping through filters
+  // pots
+  openHandle   = controls.addPot(BA_EXPAND_POT1_PIN, potCalibMin, potCalibMax, potSwapDirection); // control the amount of delay
+  closeHandle  = controls.addPot(BA_EXPAND_POT2_PIN, potCalibMin, potCalibMax, potSwapDirection); 
+  volumeHandle = controls.addPot(BA_EXPAND_POT3_PIN, potCalibMin, potCalibMax, potSwapDirection); 
+  // leds
+  led1Handle = controls.addOutput(BA_EXPAND_LED1_PIN);
+  led2Handle = controls.addOutput(BA_EXPAND_LED2_PIN); // will illuminate when pressing SW2
+
+  // Disable the audio codec first
+  codec.disable();
+  AudioMemory(128);
+
+  // Enable the codec
+  Serial.println("Enabling codec...\n");
+  codec.enable();
+  codec.setHeadphoneVolume(1.0f); // Max headphone volume
+
+  // We have to request memory be allocated to our slot.
+  externalSram.requestMemory(&delaySlot, SPI_MEM0_SIZE_BYTES, MemSelect::MEM0, true);
+
+  // Configure the LED to indicate the gate status, this is controlled directly by SOS effect, not by
+  // by BAPhysicalControls
+  sos.setGateLedGpio(BA_EXPAND_LED1_PIN);
+
+  // Besure to enable the delay. When disabled, audio is is completely blocked
+  // to minimize resources to nearly zero.
+  sos.enable(); 
+
+  // Set some default values.
+  // These can be changed by sending MIDI CC messages over the USB using
+  // the BAMidiTester application.
+  sos.bypass(false);
+  sos.gateOpenTime(3000.0f);
+  sos.gateCloseTime(1000.0f);
+  sos.feedback(0.9f);
+
+  // Setup effects on the SOLO channel
+  gainModule.gain(0, 0.25); // the reverb unit clips easily if the input is too high
+  delayModule.delay(0, 50.0f); // 50 ms slapback delay
+
+  // Setup 2-stages of LPF, cutoff 4500 Hz, Q-factor 0.7071 (a 'normal' Q-factor)
+  cabFilter.setLowpass(0, 4500, .7071);
+  cabFilter.setLowpass(1, 4500, .7071);
+
+  // Setup the Mixer
+  mixer.gain(0, 0.5f); // SOLO Dry gain
+  mixer.gain(1, 0.5f); // SOLO Wet gain
+  mixer.gain(1, 1.0f); // SOS gain
+  
+}
+
+
+
+void loop() {
+
+  float potValue;
+
+  // Check if SW1 has been toggled (pushed) and trigger the gate
+  // LED1 will be directly control by the SOS effect, not by BAPhysicalControls
+  if (controls.isSwitchToggled(gateHandle)) {
+    sos.trigger(); 
+    Serial.println("GATE OPEN is triggered");
+  }
+
+  // Use SW2 to clear out the SOS delayline
+  controls.setOutput(led2Handle, controls.getSwitchValue(led2Handle));
+  if (controls.isSwitchToggled(clearHandle)) {
+    sos.clear();
+    Serial.println("GATE CLEAR is triggered");
+  }
+
+  // Use POT1 (left) to control the OPEN GATE time
+  if (controls.checkPotValue(openHandle, potValue)) {
+    // Pot has changed
+    sos.gateOpenTime(potValue * MAX_GATE_TIME_MS);
+    Serial.println(String("New OPEN GATE setting (ms): ") + (potValue * MAX_GATE_TIME_MS));
+  }
+
+  // Use POT2 (right) to control the feedback setting
+  if (controls.checkPotValue(closeHandle, potValue)) {
+    // Pot has changed
+    sos.gateOpenTime(potValue * MAX_GATE_TIME_MS);
+    Serial.println(String("New CLOSE GATE setting (ms): ") + (potValue * MAX_GATE_TIME_MS));
+  }
+
+  // Use POT3 (centre) to control the sos effect volume
+  if (controls.checkPotValue(volumeHandle, potValue)) {
+    // Pot has changed
+    Serial.println(String("New SOS VOLUME setting: ") + potValue);
+    sos.volume(potValue);
+  }
+
+  // Use the 'u' and 'd' keys to adjust headphone volume across ten levels.
+  if (Serial) {
+    if (Serial.available() > 0) {
+      while (Serial.available()) {
+        char key = Serial.read();
+        if (key == 'u') { 
+          headphoneVolume = (headphoneVolume + 1) % MAX_HEADPHONE_VOL;
+          Serial.println(String("Increasing HEADPHONE volume to ") + headphoneVolume);
+        }
+        else if (key == 'd') { 
+          headphoneVolume = (headphoneVolume - 1) % MAX_HEADPHONE_VOL;
+          Serial.println(String("Decreasing HEADPHONE volume to ") + headphoneVolume);
+        }
+        codec.setHeadphoneVolume(static_cast<float>(headphoneVolume) / static_cast<float>(MAX_HEADPHONE_VOL));
+      }
+    }
+  }
+  if (loopCount % 524288 == 0) {
+    Serial.print("Processor Usage, Total: "); Serial.print(AudioProcessorUsage());
+    Serial.print("% ");
+    Serial.print(" sos: "); Serial.print(sos.processorUsage());
+    Serial.println("%");
+  }
+  loopCount++;
+
+}
+

examples/Delay/SoundOnSoundExpansionDemo/name.c

@@ -0,0 +1,19 @@
+// To give your project a unique name, this code must be
+// placed into a .c file (its own tab).  It can not be in
+// a .cpp file or your main sketch (the .ino file).
+
+#include "usb_names.h"
+
+// Edit these lines to create your own name.  The length must
+// match the number of characters in your custom name.
+
+#define MIDI_NAME   {'B','l','a','c','k','a','d','d','r',' ','A','u','d','i','o',' ','T','G','A',' ','P','r','o'}
+#define MIDI_NAME_LEN  23
+
+// Do not change this part.  This exact format is required by USB.
+
+struct usb_string_descriptor_struct usb_string_product_name = {
+        2 + MIDI_NAME_LEN * 2,
+        3,
+        MIDI_NAME
+};

src/AudioEffectAnalogDelay.h

@@ -86,11 +86,22 @@ public:
 	/// @param delaySamples the request delay in audio samples. Must be less than max delay.
 	void delay(size_t delaySamples);
 
+	/// Set the delay as a fraction of the maximum delay.
+	/// The value should be between 0.0f and 1.0f
+	void delayFractionMax(float delayFraction);
+
 	/// Bypass the effect.
 	/// @param byp when true, bypass wil disable the effect, when false, effect is enabled.
     /// Note that audio still passes through when bypass is enabled.
 	void bypass(bool byp) { m_bypass = byp; }
 
+	/// Get if the effect is bypassed
+	/// @returns true if bypassed, false if not bypassed
+	bool isBypass() { return m_bypass; }
+
+	/// Toggle the bypass effect
+	void toggleBypass() { m_bypass = !m_bypass; }
+
 	/// Set the amount of echo feedback (a.k.a regeneration).
 	/// @param feedback a floating point number between 0.0 and 1.0.
 	void feedback(float feedback) { m_feedback = feedback; }

src/AudioEffectSOS.h

@@ -75,6 +75,9 @@ public:
     /// Activate the gate automation. Input gate will open, then close.
     void trigger() { m_inputGateAuto.trigger(); }
 
+    /// Activate the delay clearing automation. Input signal will mute, gate will open, then close.
+    void clear() { m_clearFeedbackAuto.trigger(); }
+
     /// Set the output volume. This affect both the wet and dry signals.
     /// @details The default is 1.0.
     /// @param vol Sets the output volume between -1.0 and +1.0

src/BAAudioControlWM8731.h

@@ -72,6 +72,10 @@ public:
 	///param val when true, channels are swapped, else normal.
 	void setLeftRightSwap(bool val);
 
+	/// Set the volume for the codec's built-in headphone amp
+	/// @param volume the input volume level from 0.0f to 1.0f;
+	void setHeadphoneVolume(float volume);
+
 	/// Mute/unmute the output DAC, affects both Left and Right output channels.
 	/// @param when true, output DAC is muted, when false, unmuted.
 	void setDacMute(bool val);

src/BAPhysicalControls.h

@@ -4,7 +4,7 @@
  *  @company Blackaddr Audio
  *
  *  BAPhysicalControls is a general purpose class for handling an array of
- *  pots and switches.
+ *  pots, switches, rotary encoders and outputs (for LEDs or relays).
  *
  *  @copyright This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -28,58 +28,115 @@
 
 namespace BALibrary {
 
+constexpr bool SWAP_DIRECTION = true;    ///< Use when specifying direction should be swapped
+constexpr bool NOSWAP_DIRECTION = false; ///< Use when specifying direction should not be swapped
+
+/// Convenience class for handling a digital output with regard to setting and toggling stage
 class DigitalOutput {
 public:
+	DigitalOutput() = delete; // delete the default constructor
+
+	/// Construct an object to control the specified pin
+	/// @param pin the "Logical Arduino" pin number (not the physical pin number
 	DigitalOutput(uint8_t pin) : m_pin(pin) {}
+
+	/// Set the output value
+	/// @param val when zero output is low, otherwise output his high
 	void set(int val);
+
+	/// Toggle the output value current state
 	void toggle(void);
 
 private:
-	uint8_t m_pin;
-	int m_val = 0;
+	uint8_t m_pin; ///< store the pin associated with this output
+	int m_val = 0; ///< store the value to support toggling
 };
 
+/// Convenience class for handling an analog pot as a control. When calibrated,
+/// returns a float between 0.0 and 1.0.
 class Potentiometer {
 public:
+	/// Calibration data for a pot includes it's min and max value, as well as whether
+	/// direction should be swapped. Swapping depends on the physical orientation of the
+	/// pot.
 	struct Calib {
-		unsigned min;
-		unsigned max;
-		bool swap;
+		unsigned min; ///< The value from analogRead() when the pot is fully counter-clockwise (normal orientation)
+		unsigned max; ///< The value from analogRead() when the pot is fully clockwise (normal orientation)
+		bool swap;    ///< when orientation is such that fully clockwise would give max reading, swap changes it to the min
 	};
-	Potentiometer(uint8_t pin, unsigned minCalibration, unsigned maxCalibration)
-        : m_pin(pin), m_swapDirection(false), m_minCalibration(minCalibration), m_maxCalibration(maxCalibration) {}
 
-	Potentiometer(uint8_t pin, unsigned minCalibration, unsigned maxCalibration, bool swapDirection)
-        : m_pin(pin), m_swapDirection(swapDirection), m_minCalibration(minCalibration), m_maxCalibration(maxCalibration) {}
+	Potentiometer() = delete; // delete the default constructor
+
+	/// Construction requires the Arduino analog pin number, as well as calibration values.
+	/// @param analogPin The analog Arduino pin literal. This the number on the Teensy pinout preceeeded by an A in the local pin name. E.g. "A17".
+	/// @param minCalibration See Potentiometer::calibrate()
+	/// @param maxCalibration See Potentiometer::calibrate()
+	/// @param swapDirection Optional param. See Potentiometer::calibrate()
+	Potentiometer(uint8_t analogPin, unsigned minCalibration, unsigned maxCalibration, bool swapDirection = false)
+        : m_pin(analogPin), m_swapDirection(swapDirection), m_minCalibration(minCalibration), m_maxCalibration(maxCalibration) {}
 
+	/// Get new value from the pot.
+	/// @param value reference to a float, the new value will be written here. Value is between 0.0 and 1.0f.
+	/// @returns true if the value has changed, false if it has not
 	bool getValue(float &value);
+
+	/// Get the raw int value directly from analogRead()
+	/// @returns an integer between 0 and 1023.
 	int getRawValue();
+
+	/// Adjust the calibrate threshold. This is a factor that shrinks the calibration range slightly to
+	/// ensure the full range from 0.0f to 1.0f can be obtained.
+	/// @details temperature change can slightly alter the calibration values. This factor causes the value
+	/// to hit min or max just before the end of the pots travel to compensate.
+	/// @param thresholdFactor typical value is 0.01f to 0.05f
 	void adjustCalibrationThreshold(float thresholdFactor);
-	static Calib calibrate(uint8_t pin);
+
+	/// Set the amount of feedback in the IIR filter used to smooth the pot readings
+	/// @details actual filter reponse deptnds on the rate you call getValue()
+	/// @param filterValue typical values are 0.80f to 0.95f
+	void setFeedbackFitlerValue(float fitlerValue);
+
+	/// Call this static function before creating the object to obtain calibration data. The sequence
+	/// involves prompts over the Serial port.
+	/// @details E.g. call Potentiometer::calibrate(PIN). See BAExpansionCalibrate.ino in the library examples.
+	/// @param analogPin the Arduino analog pin number connected to the pot you wish to calibraate.
+	/// @returns populated Potentiometer::Calib structure
+	static Calib calibrate(uint8_t analogPin);
 
 private:
-    uint8_t m_pin;
-	bool m_swapDirection;
-	unsigned m_minCalibration;
-	unsigned m_maxCalibration;
-	unsigned m_lastValue = 0;
-	unsigned m_lastValue2 = 0;
+    uint8_t m_pin;                      ///< store the Arduino pin literal, e.g. A17
+	bool m_swapDirection;               ///< swap when pot orientation is upside down
+	unsigned m_minCalibration;          ///< stores the min pot value
+	unsigned m_maxCalibration;          ///< stores the max pot value
+	unsigned m_lastValue = 0;           ///< stores previous value
+	float m_feedbackFitlerValue = 0.9f; ///< feedback value for POT filter
 };
 
-constexpr bool ENCODER_SWAP = true;
-constexpr bool ENCODER_NOSWAP = false;
-
+/// Convenience class for rotary (quadrature) encoders. Uses Arduino Encoder under the hood.
 class RotaryEncoder : public Encoder {
 public:
+  RotaryEncoder() = delete; // delete default constructor
+
+  /// Constructor an encoder with the specified pins. Optionally swap direction and divide down the number of encoder ticks
+  /// @param pin1 the Arduino logical pin number for the 'A' on the encoder.
+  /// @param pin2 the Arduino logical pin number for the 'B' on the encoder.
+  /// @param swapDirection (OPTIONAL) set to true or false to obtain clockwise increments the counter-clockwise decrements
+  /// @param divider (OPTIONAL) controls the sensitivity of the divider. Use powers of 2. E.g. 1, 2, 4, 8, etc.
   RotaryEncoder(uint8_t pin1, uint8_t pin2, bool swapDirection = false, int divider = 1) : Encoder(pin1,pin2), m_swapDirection(swapDirection), m_divider(divider) {}
 
+  /// Get the delta (as a positive or negative number) since last call
+  /// @returns an integer representing the net change since last call
   int getChange();
+
+  /// Set the divider on the internal counter. High resolution encoders without detents can be overly sensitive.
+  /// This will helf reduce sensisitive by increasing the divider. Default = 1.
+  /// @pram divider controls the sensitivity of the divider. Use powers of 2. E.g. 1, 2, 4, 8, etc.
   void setDivider(int divider);
 
 private:
-  bool m_swapDirection;
-  int32_t m_lastPosition = 0;
-  int32_t m_divider;
+  bool m_swapDirection;       ///< specifies if increment/decrement should be swapped
+  int32_t m_lastPosition = 0; ///< store the last recorded position
+  int32_t m_divider;          ///< divides down the magnitude of change read by the encoder.
 };
 
 /// Specifies the type of control
@@ -91,9 +148,17 @@ enum class ControlType : unsigned {
   UNDEFINED        = 255 ///< undefined or uninitialized
 };
 
+/// Tjis class provides convenient interface for combinary an arbitrary number of controls of different types into
+/// one object. Supports switches, pots, encoders and digital outputs (useful for LEDs, relays).
 class BAPhysicalControls {
 public:
 	BAPhysicalControls() = delete;
+
+	/// Construct an object and reserve memory for the specified number of controls. Encoders and outptus are optional params.
+	/// @param numSwitches the number of switches or buttons
+	/// @param numPots the number of analog potentiometers
+	/// @param numEncoders the number of quadrature encoders
+	/// @param numOutputs the number of digital outputs. E.g. LEDs, relays, etc.
 	BAPhysicalControls(unsigned numSwitches, unsigned numPots, unsigned numEncoders = 0, unsigned numOutputs = 0);
 	~BAPhysicalControls() {}
 
@@ -124,24 +189,55 @@ public:
 	/// @param swapDirection reverses the which direction is considered pot minimum value
 	/// @param range the pot raw value will be mapped into a range of 0 to range
 	unsigned addPot(uint8_t pin, unsigned minCalibration, unsigned maxCalibration, bool swapDirection);
+
+	/// add an output to the controls
+	/// @param pin the pin number connected to the Arduino output
+	/// @returns a handle (unsigned) to the added output. Use this to access the output.
 	unsigned addOutput(uint8_t pin);
-	void setOutput(unsigned index, int val);
-	void toggleOutput(unsigned index);
-	int getRotaryAdjustUnit(unsigned index);
-	bool checkPotValue(unsigned index, float &value);
-    bool isSwitchToggled(unsigned index);
+
+	/// Set the output specified by the provided handle
+	/// @param handle the handle that was provided previously by calling addOutput()
+	/// @param val the value to set the output. 0 is low, not zero is high.
+	void setOutput(unsigned handle, int val);
+
+	/// Toggle the output specified by the provided handle
+	/// @param handle the handle that was provided previously by calling addOutput()
+	void toggleOutput(unsigned handle);
+
+	/// Retrieve the change in position on the specified rotary encoder
+	/// @param handle the handle that was provided previously by calling addRotary()
+	/// @returns an integer value. Positive is clockwise, negative is counter-clockwise rotation.
+	int getRotaryAdjustUnit(unsigned handle);
+
+	/// Check if the pot specified by the handle has been updated.
+	/// @param handle the handle that was provided previously by calling addPot()
+	/// @param value a reference to a float, the pot value will be written to this variable.
+	/// @returns true if the pot value has changed since previous check, otherwise false
+	bool checkPotValue(unsigned handle, float &value);
+
+	/// Check if the switch has been toggled since last call
+	/// @param handle the handle that was provided previously by calling addSwitch()
+	/// @returns true if the switch changed state, otherwise false
+    bool isSwitchToggled(unsigned handle);
+
+    /// Check if the switch is currently being pressed (held)
+	/// @param handle the handle that was provided previously by calling addSwitch()
+	/// @returns true if the switch is held in a pressed or closed state
+    bool isSwitchHeld(unsigned handle);
+
+    /// Get the value of the switch
+	/// @param handle the handle that was provided previously by calling addSwitch()
+    /// @returns the value at the switch pin, either 0 or 1.
+    int getSwitchValue(unsigned handle);
 
 private:
-  std::vector<Potentiometer> m_pots;
-  std::vector<RotaryEncoder> m_encoders;
-  std::vector<Bounce>  m_switches;
-  std::vector<DigitalOutput> m_outputs;
+  std::vector<Potentiometer> m_pots;     ///< a vector of all added pots
+  std::vector<RotaryEncoder> m_encoders; ///< a vector of all added encoders
+  std::vector<Bounce>  m_switches;       ///< a vector of all added switches
+  std::vector<DigitalOutput> m_outputs;  ///< a vector of all added outputs
 };
 
 
-
-
-
 } // BALibrary
 
 

src/effects/AudioEffectAnalogDelay.cpp

@@ -177,11 +177,11 @@ void AudioEffectAnalogDelay::delay(float milliseconds)
 
 	if (!m_externalMemory) {
 		// internal memory
-		QueuePosition queuePosition = calcQueuePosition(milliseconds);
-		Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
+		//QueuePosition queuePosition = calcQueuePosition(milliseconds);
+		//Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
 	} else {
 		// external memory
-		Serial.println(String("CONFIG: delay:") + delaySamples);
+		//Serial.println(String("CONFIG: delay:") + delaySamples);
 		ExtMemSlot *slot = m_memory->getSlot();
 
 		if (!slot) { Serial.println("ERROR: slot ptr is not valid"); }
@@ -200,17 +200,43 @@ void AudioEffectAnalogDelay::delay(size_t delaySamples)
 
 	if (!m_externalMemory) {
 		// internal memory
-		QueuePosition queuePosition = calcQueuePosition(delaySamples);
-		Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
+		//QueuePosition queuePosition = calcQueuePosition(delaySamples);
+		//Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
 	} else {
 		// external memory
-		Serial.println(String("CONFIG: delay:") + delaySamples);
+		//Serial.println(String("CONFIG: delay:") + delaySamples);
 		ExtMemSlot *slot = m_memory->getSlot();
 		if (!slot->isEnabled()) {
 			slot->enable();
 		}
 	}
-	m_delaySamples= delaySamples;
+	m_delaySamples = delaySamples;
+}
+
+void AudioEffectAnalogDelay::delayFractionMax(float delayFraction)
+{
+	size_t delaySamples = static_cast<size_t>(static_cast<float>(m_memory->getMaxDelaySamples()) * delayFraction);
+
+	if (delaySamples > m_memory->getMaxDelaySamples()) {
+	    // this exceeds max delay value, limit it.
+	    delaySamples = m_memory->getMaxDelaySamples();
+	}
+
+	if (!m_memory) { Serial.println("delay(): m_memory is not valid"); }
+
+	if (!m_externalMemory) {
+		// internal memory
+		//QueuePosition queuePosition = calcQueuePosition(delaySamples);
+		//Serial.println(String("CONFIG: delay:") + delaySamples + String(" queue position ") + queuePosition.index + String(":") + queuePosition.offset);
+	} else {
+		// external memory
+		//Serial.println(String("CONFIG: delay:") + delaySamples);
+		ExtMemSlot *slot = m_memory->getSlot();
+		if (!slot->isEnabled()) {
+			slot->enable();
+		}
+	}
+	m_delaySamples = delaySamples;
 }
 
 void AudioEffectAnalogDelay::m_preProcessing(audio_block_t *out, audio_block_t *dry, audio_block_t *wet)

src/peripherals/BAAudioControlWM8731.cpp

@@ -60,6 +60,26 @@ constexpr int WM8731_RIGHT_INPUT_MUTE_SHIFT = 7;
 constexpr int WM8731_LINK_RIGHT_LEFT_IN_ADDR = 1;
 constexpr int WM8731_LINK_RIGHT_LEFT_IN_MASK = 0x100;
 constexpr int WM8731_LINK_RIGHT_LEFT_IN_SHIFT = 8;
+// Register 2
+constexpr int WM8731_LEFT_HEADPHONE_VOL_ADDR = 2;
+constexpr int WM8731_LEFT_HEADPHONE_VOL_MASK = 0x7F;
+constexpr int WM8731_LEFT_HEADPHONE_VOL_SHIFT = 0;
+constexpr int WM8731_LEFT_HEADPHONE_ZCD_ADDR = 2;
+constexpr int WM8731_LEFT_HEADPHONE_ZCD_MASK = 0x80;
+constexpr int WM8731_LEFT_HEADPHONE_ZCD_SHIFT = 7;
+constexpr int WM8731_LEFT_HEADPHONE_LINK_ADDR = 2;
+constexpr int WM8731_LEFT_HEADPHONE_LINK_MASK = 0x100;
+constexpr int WM8731_LEFT_HEADPHONE_LINK_SHIFT = 8;
+// Register 3
+constexpr int WM8731_RIGHT_HEADPHONE_VOL_ADDR = 3;
+constexpr int WM8731_RIGHT_HEADPHONE_VOL_MASK = 0x7F;
+constexpr int WM8731_RIGHT_HEADPHONE_VOL_SHIFT = 0;
+constexpr int WM8731_RIGHT_HEADPHONE_ZCD_ADDR = 3;
+constexpr int WM8731_RIGHT_HEADPHONE_ZCD_MASK = 0x80;
+constexpr int WM8731_RIGHT_HEADPHONE_ZCD_SHIFT = 7;
+constexpr int WM8731_RIGHT_HEADPHONE_LINK_ADDR = 3;
+constexpr int WM8731_RIGHT_HEADPHONE_LINK_MASK = 0x100;
+constexpr int WM8731_RIGHT_HEADPHONE_LINK_SHIFT = 8;
 // Register 4
 constexpr int WM8731_ADC_BYPASS_ADDR = 4;
 constexpr int WM8731_ADC_BYPASS_MASK = 0x8;
@@ -157,11 +177,11 @@ void BAAudioControlWM8731::enable(void)
 	setRightInMute(false);
 	setDacMute(false); // unmute the DAC
 
-	// mute the headphone outputs
-	write(WM8731_REG_LHEADOUT, 0x00);      // volume off
-	regArray[WM8731_REG_LHEADOUT] = 0x00;
-	write(WM8731_REG_RHEADOUT, 0x00);
-	regArray[WM8731_REG_RHEADOUT] = 0x00;
+	// link, but mute the headphone outputs
+	regArray[WM8731_REG_LHEADOUT] = WM8731_LEFT_HEADPHONE_LINK_MASK;
+	write(WM8731_REG_LHEADOUT, regArray[WM8731_REG_LHEADOUT]);      // volume off
+	regArray[WM8731_REG_RHEADOUT] = WM8731_RIGHT_HEADPHONE_LINK_MASK;
+	write(WM8731_REG_RHEADOUT, regArray[WM8731_REG_RHEADOUT]);
 
 	/// Configure the audio interface
 	write(WM8731_REG_INTERFACE, 0x02); // I2S, 16 bit, MCLK slave
@@ -251,6 +271,25 @@ void BAAudioControlWM8731::setLeftRightSwap(bool val)
 	write(WM8731_LRSWAP_ADDR, regArray[WM8731_LRSWAP_ADDR]);
 }
 
+void BAAudioControlWM8731::setHeadphoneVolume(float volume)
+{
+	// the codec volume goes from 0x30 to 0x7F. Anything below 0x30 is mute.
+	// 0dB gain is 0x79. Total range is 0x50 (80) possible values.
+	unsigned vol;
+	constexpr unsigned RANGE = 80.0f;
+	if (volume < 0.0f) {
+		vol = 0;
+	} else if (volume > 1.0f) {
+		vol = 0x7f;
+	} else {
+		vol = 0x2f + static_cast<unsigned>(volume * RANGE);
+	}
+	regArray[WM8731_LEFT_HEADPHONE_VOL_ADDR] &= ~WM8731_LEFT_HEADPHONE_VOL_MASK; // clear the volume first
+	regArray[WM8731_LEFT_HEADPHONE_VOL_ADDR] |=
+			((vol << WM8731_LEFT_HEADPHONE_VOL_SHIFT) & WM8731_LEFT_HEADPHONE_VOL_MASK);
+	write(WM8731_LEFT_HEADPHONE_VOL_ADDR, regArray[WM8731_LEFT_HEADPHONE_VOL_ADDR]);
+}
+
 // Dac output mute control
 void BAAudioControlWM8731::setDacMute(bool val)
 {

src/peripherals/BAPhysicalControls.cpp

@@ -78,21 +78,21 @@ unsigned BAPhysicalControls::addOutput(uint8_t pin) {
 	return m_outputs.size()-1;
 }
 
-void BAPhysicalControls::setOutput(unsigned index, int val) {
-	if (index >= m_outputs.size()) { return; }
-	m_outputs[index].set(val);
+void BAPhysicalControls::setOutput(unsigned handle, int val) {
+	if (handle >= m_outputs.size()) { return; }
+	m_outputs[handle].set(val);
 }
 
-void BAPhysicalControls::toggleOutput(unsigned index) {
-	if (index >= m_outputs.size()) { return; }
-	m_outputs[index].toggle();
+void BAPhysicalControls::toggleOutput(unsigned handle) {
+	if (handle >= m_outputs.size()) { return; }
+	m_outputs[handle].toggle();
 }
 
 
-int BAPhysicalControls::getRotaryAdjustUnit(unsigned index) {
-	if (index >= m_encoders.size()) { return 0; } // index is greater than number of encoders
+int BAPhysicalControls::getRotaryAdjustUnit(unsigned handle) {
+	if (handle >= m_encoders.size()) { return 0; } // handle is greater than number of encoders
 
-	int encoderAdjust = m_encoders[index].getChange();
+	int encoderAdjust = m_encoders[handle].getChange();
 	if (encoderAdjust != 0) {
 		  // clip the adjust to maximum abs value of 1.
 		  int encoderAdjust = (encoderAdjust > 0) ? 1 : -1;
@@ -101,14 +101,14 @@ int BAPhysicalControls::getRotaryAdjustUnit(unsigned index) {
 	return encoderAdjust;
 }
 
-bool BAPhysicalControls::checkPotValue(unsigned index, float &value) {
-	if (index >= m_pots.size()) { return false;} // index is greater than number of pots
-	return m_pots[index].getValue(value);
+bool BAPhysicalControls::checkPotValue(unsigned handle, float &value) {
+	if (handle >= m_pots.size()) { return false;} // handle is greater than number of pots
+	return m_pots[handle].getValue(value);
 }
 
-bool BAPhysicalControls::isSwitchToggled(unsigned index) {
-	if (index >= m_switches.size()) { return 0; } // index is greater than number of switches
-	Bounce &sw = m_switches[index];
+bool BAPhysicalControls::isSwitchToggled(unsigned handle) {
+	if (handle >= m_switches.size()) { return 0; } // handle is greater than number of switches
+	Bounce &sw = m_switches[handle];
 
 	if (sw.update() && sw.fallingEdge()) {
 	  return true;
@@ -117,6 +117,26 @@ bool BAPhysicalControls::isSwitchToggled(unsigned index) {
 	}
 }
 
+bool BAPhysicalControls::isSwitchHeld(unsigned handle)
+{
+	if (handle >= m_switches.size()) { return 0; } // handle is greater than number of switches
+	Bounce &sw = m_switches[handle];
+
+	if (sw.read()) {
+		return true;
+	} else {
+		return false;
+	}
+}
+
+int BAPhysicalControls::getSwitchValue(unsigned handle)
+{
+	if (handle >= m_switches.size()) { return 0; } // handle is greater than number of switches
+	Bounce &sw = m_switches[handle];
+
+	return sw.read();
+}
+
 ///////////////////////////
 
 void DigitalOutput::set(int val) {
@@ -129,25 +149,31 @@ void DigitalOutput::toggle(void) {
 	digitalWriteFast(m_pin, m_val);
 }
 
+void Potentiometer::setFeedbackFitlerValue(float fitlerValue)
+{
+	m_feedbackFitlerValue = fitlerValue;
+}
 
 bool Potentiometer::getValue(float &value) {
 
+	bool newValue = true;
+
 	unsigned val = analogRead(m_pin); // read the raw value
-	// Return false if the value is the same as the last sample, or 2 samples ago. The second check is to
-	// prevent oscillating between two values.
-	if ((val == m_lastValue) || (val == m_lastValue2)) {
-		return false;
-	}
+	// Use an IIR filter to smooth out the noise in the pot readings
+	unsigned valFilter = ( (1.0f - m_feedbackFitlerValue)*val + m_feedbackFitlerValue*m_lastValue);
 
-	// Otherwise update the last value
-	m_lastValue = val;
 	// constrain it within the calibration values, them map it to the desired range.
-	val = constrain(val, m_minCalibration, m_maxCalibration);
-	value = static_cast<float>(val - m_minCalibration) / static_cast<float>(m_maxCalibration);
+	valFilter = constrain(valFilter, m_minCalibration, m_maxCalibration);
+	if (valFilter == m_lastValue) {
+		newValue = false;
+	}
+	m_lastValue = valFilter;
+
+	value = static_cast<float>(valFilter - m_minCalibration) / static_cast<float>(m_maxCalibration);
 	if (m_swapDirection) {
 		value = 1.0f - value;
 	}
-    return true;
+    return newValue;
 }
 
 int Potentiometer::getRawValue() {

src/peripherals/DmaSpi.cpp

@@ -0,0 +1,13 @@
+#include "DmaSpi.h"
+
+#if defined(KINETISK)
+DmaSpi0 DMASPI0;
+#if defined(__MK66FX1M0__)
+DmaSpi1 DMASPI1;
+//DmaSpi2 DMASPI2;
+#endif
+#elif defined (KINETISL)
+DmaSpi0 DMASPI0;
+DmaSpi1 DMASPI1;
+#else 
+#endif // defined