1 files changed, 85 insertions, 57 deletions

diff --git a/esp32/lego-piano.ino b/esp32/lego-piano.ino
index 575f55e..01b3bb7 100644
--- a/esp32/lego-piano.ino
+++ b/esp32/lego-piano.ino
@@ -17,9 +17,16 @@
  */
 
 #include <driver/dac.h>
+#include <driver/i2s.h>
+
+#define TSF_IMPLEMENTATION
+#define TSF_NO_STDIO
+#include "../ESP8266Audio/src/libtinysoundfont/tsf.h"
+
+#include "../RingBuffer/src/RingBuf.h"
+#include "font.h"
 
 int currentLed = 0;
-int lastSeen = -1;
 
 #define DEBUG 0
 
@@ -33,15 +40,36 @@ const int ampEnable = 32;
 
 const int octave_shift = 2;
 
+const int sampleRate = 11025;
+
+char pressed[row_count*col_count] = { 0 };
+
+tsf* g_TinySoundFont = 0;
+const i2s_port_t i2sPort = I2S_NUM_0;
+
 void setup() {
   Serial.begin(115200);
 
   pinMode(ampEnable, OUTPUT);
   digitalWrite(ampEnable, LOW);
 
-  dac_i2s_disable();
+  dac_i2s_enable();
   dac_output_enable(DAC_CHANNEL_1);
 
+  static const i2s_config_t i2s_config = {
+      .mode = (i2s_mode_t)( I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN ),
+      .sample_rate = sampleRate,
+      .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,
+      .channel_format = I2S_CHANNEL_FMT_ALL_RIGHT,
+      .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1, // high interrupt priority
+      .dma_buf_count = 8,
+      .dma_buf_len = 64,
+      .use_apll = false
+  };
+
+  i2s_driver_install(i2sPort, &i2s_config, 0, NULL);
+  i2s_set_dac_mode(I2S_DAC_CHANNEL_RIGHT_EN); // only dac1
+
   for (int i=0;i<row_count;++i) {
     pinMode(rows[i], OUTPUT|PULLUP);
     pinMode(adc[i], INPUT);
@@ -51,29 +79,19 @@ void setup() {
   }
 
   currentLed = 0;
-  lastSeen = -1;
-}
-
-void play(uint32_t freq) {
-  dac_cw_config_t wave_config = {
-  en_ch: DAC_CHANNEL_1,
-  scale: DAC_CW_SCALE_2,
-  phase: DAC_CW_PHASE_0,
-  freq: octave_shift*freq,
-  offset: 0,
-  };
 
-  dac_cw_generator_config(&wave_config);
-  dac_cw_generator_enable();
+  g_TinySoundFont = tsf_load_memory(SoundFont, sizeof(SoundFont));
+  if (g_TinySoundFont) {
+    // render at 5kHz
+    tsf_set_output(g_TinySoundFont, TSF_MONO, sampleRate, 0);
+  }
+  else {
+    Serial.println("failed to start tsf");
+  }
 
   digitalWrite(ampEnable, HIGH);
 }
 
-void mute() {
-  digitalWrite(ampEnable, LOW);
-  dac_cw_generator_disable();
-}
-
 void tristate(int pin) {
   pinMode(pin,OUTPUT|PULLDOWN);
   digitalWrite(pin,LOW);
@@ -123,35 +141,9 @@ int sense(int led) {
   return value < 500;
 }
 
-uint32_t notes[] = {
-                    261, // C4
-                    277,
-                    294, // D4
-                    311,
-                    330, // E4
-                    349, // F4
-                    370,
-                    392, // G4
-                    415,
-                    440, // A4
-                    466,
-                    494, // B4
-
-                    523, // C5
-                    554,
-                    587, // D5
-                    622,
-                    659, // E5
-                    698, // F5
-                    740,
-                    783, // G5
-                    831,
-                    880, // A5
-                    932,
-                    988, // B5
-
-                    1046, // C6
-};
+const size_t bufferSize = 1000;
+RingBuf<short, bufferSize> buffer;
+short intermediateBuffer[bufferSize];
 
 void loop() {
 #if DEBUG & 0x01
@@ -160,19 +152,55 @@ void loop() {
 #endif
 
   enableLed(currentLed);
-  delay(5);
-  if (sense(currentLed)) {
-    if (lastSeen != currentLed) {
-      lastSeen = currentLed;
+  unsigned long t = millis();
+  size_t written=100;
+  short value;
+  // fill the I2S buffer
+  while (written > 0) {
+    // we don't want to drop an element from the buffer if we then
+    // can't write it! so we peek at the buffer, try to write, and pop
+    // if successful
+    value=buffer[0] + 32768; // tsf produces *signed* shorts, i2s wants *unsigned*
+    i2s_write(i2sPort, &value, sizeof(value), &written, 0);
+    if (written > 0) buffer.pop(value);
+  }
+
+  int toFill = buffer.maxSize() - buffer.size();
+  if (toFill > 100) {
+    tsf_render_short(g_TinySoundFont, intermediateBuffer, toFill, 0);
+    for (int i=0;i<toFill;++i) {
+      buffer.push(intermediateBuffer[i]);
+    }
+  }
+
+  while (millis() == t) {
+    delayMicroseconds(100);
+  }
+
+  if (sense(currentLed)) { // currently pressed
+    if (!pressed[currentLed]) { // was not pressed previously?
       Serial.print(currentLed);
       Serial.println(" proximity!");
-      play(notes[currentLed]);
+
+      pressed[currentLed]=1; // mark it pressed
+      if (g_TinySoundFont) {
+        // start the note
+        tsf_note_on(g_TinySoundFont, 0, 36 + currentLed, 1.0f);
+      }
     }
   }
-  else if (lastSeen == currentLed) {
-    lastSeen = -1;
-    mute();
+  // not pressed currently
+  else if (pressed[currentLed]) { // was pressed previously?
+    Serial.print(currentLed);
+    Serial.println(" released!");
+
+    pressed[currentLed]=0; // mark it no longer pressed
+    if (g_TinySoundFont) {
+      // stop the note
+      tsf_note_off(g_TinySoundFont, 0, 36 + currentLed);
+    }
   }
 
   currentLed = (currentLed+1)%(row_count*col_count);
+
 }
\ No newline at end of file