Volume control! Reasonable default volume! Hooray!

src/audio/i2s_audio_output.cpp

@@ -10,6 +10,7 @@
 
 #include <algorithm>
 #include <cstddef>
+#include <cstdint>
 #include <memory>
 #include <variant>
 
@@ -23,19 +24,32 @@
 #include "i2s_dac.hpp"
 #include "result.hpp"
 #include "stream_info.hpp"
+#include "wm8523.hpp"
 
 static const char* kTag = "I2SOUT";
 
 namespace audio {
 
+// Consumer line level = 0.316 VRMS = -10db = 61
+// Professional line level = 1.228 VRMS = +4dB = 111
+// Cliipping level = 2.44 VRMS = 133?
+// all into 650 ohms
+
+static constexpr uint16_t kMaxVolume = 0x1ff;
+static constexpr uint16_t kMinVolume = 0b0;
+static constexpr uint16_t kMaxVolumeBeforeClipping = 0x185;
+static constexpr uint16_t kLineLevelVolume = 0x13d;
+static constexpr uint16_t kDefaultVolume = 0x128;
+
 I2SAudioOutput::I2SAudioOutput(drivers::IGpios* expander,
                                std::weak_ptr<drivers::I2SDac> dac)
     : expander_(expander),
       dac_(dac.lock()),
       current_config_(),
       left_difference_(0),
-      attenuation_() {
+      current_volume_(kDefaultVolume),
-  SetVolume(25);  // For testing
+      max_volume_(kLineLevelVolume){
+  SetVolume(GetVolume());
   dac_->SetSource(stream());
 }
 
@@ -53,63 +67,50 @@ auto I2SAudioOutput::SetInUse(bool in_use) -> void {
 }
 
 auto I2SAudioOutput::SetVolumeImbalance(int_fast8_t balance) -> void {
-  // TODO.
+  left_difference_ = balance;
+  SetVolume(GetVolume());
 }
 
 auto I2SAudioOutput::SetVolume(uint_fast8_t percent) -> void {
-  // TODO.
+  percent = std::min<uint_fast8_t>(percent, 100);
-}
+  float new_value = static_cast<float>(max_volume_) / 100 * percent;
+  current_volume_ = std::max<float>(new_value, kMinVolume);
+  ESP_LOGI(kTag, "set volume to %u%% = %u", percent, current_volume_);
 
-auto I2SAudioOutput::GetVolume() -> uint_fast8_t {
+  int32_t left_unclamped = current_volume_ + left_difference_;
-  // TODO.
+  uint16_t left = std::clamp<int32_t>(left_unclamped, kMinVolume, max_volume_);
-  return 100;
-}
 
-auto I2SAudioOutput::GetAdjustedMaxAttenuation() -> int_fast8_t {
+  using drivers::wm8523::Register;
-  // TODO
+  drivers::wm8523::WriteRegister(Register::kDacGainLeft, left);
-  return 0;
+  drivers::wm8523::WriteRegister(Register::kDacGainRight, current_volume_ | 0x200);
 }
 
-static uint8_t vol = 0xFF;
+auto I2SAudioOutput::GetVolume() -> uint_fast8_t {
+  return 
+    static_cast<uint_fast8_t>(
+        static_cast<float>(current_volume_) / max_volume_ * 100.0f);
+}
 
 auto I2SAudioOutput::AdjustVolumeUp() -> bool {
-  vol += 0xF;
+  if (GetVolume() >= 100) {
-  {
+    return false;
-    drivers::I2CTransaction transaction;
-    transaction.start()
-        .write_addr(0b0011010, I2C_MASTER_WRITE)
-        .write_ack(6, 0b01, vol)
-        .stop();
-    transaction.Execute();
   }
-  {
+  if (GetVolume() >= 95) {
-    drivers::I2CTransaction transaction;
+    SetVolume(100);
-    transaction.start()
+  } else {
-        .write_addr(0b0011010, I2C_MASTER_WRITE)
+    SetVolume(GetVolume() + 5);
-        .write_ack(7, 0b11, vol)
-        .stop();
-    transaction.Execute();
   }
   return true;
 }
 
 auto I2SAudioOutput::AdjustVolumeDown() -> bool {
-  vol -= 0xF;
+  if (GetVolume() == 0) {
-  {
+    return false;
-    drivers::I2CTransaction transaction;
-    transaction.start()
-        .write_addr(0b0011010, I2C_MASTER_WRITE)
-        .write_ack(6, 0b01, vol)
-        .stop();
-    transaction.Execute();
   }
-  {
+  if (GetVolume() <= 5) {
-    drivers::I2CTransaction transaction;
+    SetVolume(0);
-    transaction.start()
+  } else {
-        .write_addr(0b0011010, I2C_MASTER_WRITE)
+    SetVolume(GetVolume() - 5);
-        .write_ack(7, 0b11, vol)
-        .stop();
-    transaction.Execute();
   }
   return true;
 }

src/audio/include/i2s_audio_output.hpp

@@ -6,6 +6,7 @@
 
 #pragma once
 
+#include <sys/_stdint.h>
 #include <cstdint>
 #include <memory>
 #include <vector>
@@ -41,14 +42,13 @@ class I2SAudioOutput : public IAudioSink {
   I2SAudioOutput& operator=(const I2SAudioOutput&) = delete;
 
  private:
-  auto GetAdjustedMaxAttenuation() -> int_fast8_t;
-
   drivers::IGpios* expander_;
   std::shared_ptr<drivers::I2SDac> dac_;
 
   std::optional<StreamInfo::Pcm> current_config_;
   int_fast8_t left_difference_;
-  uint_fast8_t attenuation_;
+  uint16_t current_volume_;
+  uint16_t max_volume_;
 };
 
 }  // namespace audio

src/drivers/CMakeLists.txt

@@ -4,7 +4,7 @@
 
 idf_component_register(
   SRCS "touchwheel.cpp" "i2s_dac.cpp" "gpios.cpp" "battery.cpp" "storage.cpp" "i2c.cpp"
-  "spi.cpp" "display.cpp" "display_init.cpp" "samd.cpp" "relative_wheel.cpp"
+  "spi.cpp" "display.cpp" "display_init.cpp" "samd.cpp" "relative_wheel.cpp" "wm8523.cpp"
   INCLUDE_DIRS "include"
   REQUIRES "esp_adc" "fatfs" "result" "lvgl" "span" "tasks")
 target_compile_options(${COMPONENT_LIB} PRIVATE ${EXTRA_WARNINGS})

src/drivers/i2s_dac.cpp

@@ -28,6 +28,7 @@
 #include "hal/i2c_types.h"
 
 #include "gpios.hpp"
+#include "wm8523.hpp"
 #include "hal/i2s_types.h"
 #include "i2c.hpp"
 #include "soc/clk_tree_defs.h"
@@ -36,28 +37,6 @@ namespace drivers {
 
 static const char* kTag = "i2s_dac";
 static const i2s_port_t kI2SPort = I2S_NUM_0;
-static const uint8_t kWm8523Address = 0b0011010;
-
-enum Register {
-  kReset = 0,
-  kRevision = 1,
-  kPsCtrl = 2,
-  kAifCtrl1 = 3,
-  kAifCtrl2 = 4,
-  kDacCtrl = 5,
-  kDacGainLeft = 6,
-  kDacGainRight = 7,
-  kZeroDetect = 8,
-};
-
-auto write_register(Register reg, uint8_t msb, uint8_t lsb) -> esp_err_t {
-  I2CTransaction transaction;
-  transaction.start()
-      .write_addr(kWm8523Address, I2C_MASTER_WRITE)
-      .write_ack(reg, msb, lsb)
-      .stop();
-  return transaction.Execute();
-}
 
 auto I2SDac::create(IGpios* expander) -> std::optional<I2SDac*> {
   i2s_chan_handle_t i2s_handle;
@@ -110,17 +89,11 @@ I2SDac::I2SDac(IGpios* gpio, i2s_chan_handle_t i2s_handle)
   gpio_->WriteSync(IGpios::Pin::kAmplifierEnable, false);
 
   // Reset all registers back to their default values.
-  write_register(kReset, 0, 1);
+  wm8523::WriteRegister(wm8523::Register::kReset, 1);
   vTaskDelay(pdMS_TO_TICKS(10));
 
   // Power up the charge pump.
-  write_register(kPsCtrl, 0, 0b01);
+  wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b01);
-
-  // TODO: testing
-  // write_register(kDacGainLeft, 0b01, 0x50);
-  // write_register(kDacGainRight, 0b11, 0x50);
-  write_register(kDacGainLeft, 0b01, 0x0);
-  write_register(kDacGainRight, 0b11, 0x0);
 }
 
 I2SDac::~I2SDac() {
@@ -130,15 +103,23 @@ I2SDac::~I2SDac() {
 
 auto I2SDac::Start() -> void {
   gpio_->WriteSync(IGpios::Pin::kAmplifierEnable, true);
+  vTaskDelay(pdMS_TO_TICKS(1));
+  wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b10);
 
-  i2s_channel_enable(i2s_handle_);
+  uint8_t zeroes[256] {0};
-  write_register(kPsCtrl, 0, 0b11);
+  size_t bytes_loaded = 0;
+  esp_err_t res = ESP_OK;
+  do {
+    res = i2s_channel_preload_data(i2s_handle_, zeroes, 256, &bytes_loaded);
+  } while (bytes_loaded > 0 && res == ESP_OK);
 
+  wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b11);
+  i2s_channel_enable(i2s_handle_);
   i2s_active_ = true;
 }
 
 auto I2SDac::Stop() -> void {
-  write_register(kPsCtrl, 0, 0b01);
+  wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b01);
   i2s_channel_disable(i2s_handle_);
 
   gpio_->WriteSync(IGpios::Pin::kAmplifierEnable, false);
@@ -148,8 +129,15 @@ auto I2SDac::Stop() -> void {
 
 auto I2SDac::Reconfigure(Channels ch, BitsPerSample bps, SampleRate rate)
     -> void {
-  write_register(kPsCtrl, 0, 0b01);
+  if (i2s_active_) {
+    // Ramp down into mute instead of just outright stopping to minimise any
+    // clicks and pops.
+    wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b10);
+    vTaskDelay(pdMS_TO_TICKS(1));
+
+    wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b01);
     i2s_channel_disable(i2s_handle_);
+  }
 
   switch (ch) {
     case CHANNELS_MONO:
@@ -190,13 +178,13 @@ auto I2SDac::Reconfigure(Channels ch, BitsPerSample bps, SampleRate rate)
   ESP_ERROR_CHECK(i2s_channel_reconfig_std_clock(i2s_handle_, &clock_config_));
 
   // Set the correct word size, and set the input format to I2S-justified.
-  write_register(kAifCtrl1, 0, (word_length << 3) | 0b10);
+  wm8523::WriteRegister(wm8523::Register::kAifCtrl1, (word_length << 3) | 0b10);
   // Tell the DAC the clock ratio instead of waiting for it to auto detect.
-  // write_register(kAifCtrl2, 0, bps == BPS_24 ? 0b100 : 0b011);
+  wm8523::WriteRegister(wm8523::Register::kAifCtrl2, bps == BPS_24 ? 0b100 : 0b011);
 
   if (i2s_active_) {
     i2s_channel_enable(i2s_handle_);
-    write_register(kPsCtrl, 0, 0b11);
+    wm8523::WriteRegister(wm8523::Register::kPsCtrl, 0b11);
   }
 }
 

src/drivers/include/wm8523.hpp

@@ -0,0 +1,31 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+#pragma once
+
+#include <cstdint>
+#include <optional>
+
+namespace drivers {
+namespace wm8523 {
+
+enum class Register : uint8_t {
+  kReset = 0,
+  kRevision = 1,
+  kPsCtrl = 2,
+  kAifCtrl1 = 3,
+  kAifCtrl2 = 4,
+  kDacCtrl = 5,
+  kDacGainLeft = 6,
+  kDacGainRight = 7,
+  kZeroDetect = 8,
+};
+
+auto ReadRegister(Register reg) -> std::optional<uint16_t>;
+auto WriteRegister(Register reg, uint16_t data) -> bool;
+auto WriteRegister(Register reg, uint8_t msb, uint8_t lsb) -> bool;
+
+}
+}

src/drivers/wm8523.cpp

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2023 jacqueline <me@jacqueline.id.au>
+ *
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+#include "wm8523.hpp"
+
+#include <cstdint>
+
+#include "esp_err.h"
+
+#include "hal/i2c_types.h"
+#include "i2c.hpp"
+
+namespace drivers {
+namespace wm8523 {
+
+static const uint8_t kAddress = 0b0011010;
+
+auto ReadRegister(Register reg) -> std::optional<uint16_t> {
+  uint8_t msb, lsb;
+  I2CTransaction transaction;
+  transaction.start()
+      .write_addr(kAddress, I2C_MASTER_WRITE)
+      .write_ack(static_cast<uint8_t>(reg))
+      .start()
+      .write_addr(kAddress, I2C_MASTER_READ)
+      .read(&msb, I2C_MASTER_ACK)
+      .read(&lsb, I2C_MASTER_LAST_NACK)
+      .stop();
+  if (transaction.Execute() != ESP_OK) {
+    return {};
+  }
+  return (msb << 8) & lsb;
+}
+
+auto WriteRegister(Register reg, uint16_t data) -> bool {
+  return WriteRegister(reg, (data >> 8) & 0xFF, data & 0xFF);
+}
+
+auto WriteRegister(Register reg, uint8_t msb, uint8_t lsb) -> bool {
+  I2CTransaction transaction;
+  transaction.start()
+      .write_addr(kAddress, I2C_MASTER_WRITE)
+      .write_ack(static_cast<uint8_t>(reg), msb, lsb)
+      .stop();
+  return transaction.Execute() == ESP_OK;
+}
+
+}
+}