From 3d76839cbcd3104ab22c5f7c7496a2090da60688 Mon Sep 17 00:00:00 2001
From: dakkar <dakkar@thenautilus.net>
Date: Fri, 21 Aug 2020 16:12:49 +0100
Subject: using arduino-esp32 branch esp32s, it plays!

that branch exposes the "cosine wave generator", so I don't have to
---
 esp32/lego-piano.ino | 73 ++++++++++++++++++++++++++--------------------------
 1 file changed, 37 insertions(+), 36 deletions(-)

diff --git a/esp32/lego-piano.ino b/esp32/lego-piano.ino
index ce11990..42c7e1a 100644
--- a/esp32/lego-piano.ino
+++ b/esp32/lego-piano.ino
@@ -18,35 +18,6 @@
 
 #include <driver/dac.h>
 
-hw_timer_t * timer = NULL;
-portMUX_TYPE timerMux = portMUX_INITIALIZER_UNLOCKED;
-
-bool play = false;
-int wave_pos = 0;
-int wave_period = 1000;
-
-// stupid square wave
-int wave() {
-  if (wave_pos < wave_period/2) {
-    return 255;
-  }
-  else {
-    return 0;
-  }
-}
-
-void IRAM_ATTR onTimer() {
-  portENTER_CRITICAL_ISR(&timerMux);
-
-  if (play) {
-    dac_output_voltage(DAC_CHANNEL_2, wave());
-    wave_pos = (wave_pos+1)%wave_period;
-  }
-
-  portEXIT_CRITICAL_ISR(&timerMux);
-}
-
-
 int currentLed = 0;
 int lastSeen = 100;
 
@@ -55,11 +26,13 @@ const int cols[] = { 34, 33, 35, 21, 22 };
 const int adc[] = { 2, 4, 12, 27, 14 };
 const int ampEnable = 32;
 
+
 void setup() {
-  Serial.begin(19200);
+  Serial.begin(115200);
 
   pinMode(ampEnable, OUTPUT);
-  dac_output_enable(DAC_CHANNEL_2);
+  dac_i2s_disable();
+  dac_output_enable(DAC_CHANNEL_1);
 
   for (int i=0;i<5;++i) {
     pinMode(rows[i], OUTPUT);
@@ -70,12 +43,27 @@ void setup() {
   currentLed = 0;
   lastSeen = 100;
 
-  timer = timerBegin(0, 2, true); // use a prescaler of 2
-  timerAttachInterrupt(timer, &onTimer, true);
-  timerAlarmWrite(timer, 5000, true);
-  timerAlarmEnable(timer);
+  digitalWrite(ampEnable, LOW);
+}
+
+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: freq,
+  offset: 0,
+  };
+
+  dac_cw_generator_config(&wave_config);
+  dac_cw_generator_enable();
 
-  play=true;
+  digitalWrite(ampEnable, HIGH);
+}
+
+void mute() {
+  digitalWrite(ampEnable, LOW);
+  dac_cw_generator_disable();
 }
 
 void tristate(int pin) {
@@ -120,6 +108,10 @@ int sense(int led) {
   return value < 500;
 }
 
+int count=0;
+uint32_t notes[] = { 440, 880, 1200 };
+int currentNote = 0;
+
 void loop() {
   /* Serial.print("current led "); */
   /* Serial.println(currentLed); */
@@ -138,4 +130,13 @@ void loop() {
   }
 
   currentLed = (currentLed+1)%25;
+
+  if (count == 450) {
+    //mute();
+  }
+  else if (count == 0) {
+    play(notes[currentNote]);
+    currentNote = (currentNote+1)%3;
+  }
+  count = (count+1)%500;
 }
\ No newline at end of file
-- 
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