Added a 'bool WM8978::begin()' function which doesn't setup i2c.

README.md

@@ -8,6 +8,9 @@ Arduino IDE library for wm8978 codec on ESP32 mcu.
 
 
 ### Example code:
+
+#### Setup i2c and wm8978 in one call
+
 ```c++
 #include <WM8978.h> /* https://github.com/CelliesProjects/wm8978-esp32 */
 #include <Audio.h>  /* https://github.com/schreibfaul1/ESP32-audioI2S */
@@ -35,13 +38,63 @@ void setup() {
     while (1) delay(100);
   }
 
-  /* Select I2S MCLK pin */
+  WiFi.begin("xxx", "xxx");
+  while (!WiFi.isConnected()) {
+    delay(10);
+  }
+
+  /* Start MCLK */
   audio.i2s_mclk_pin_select(I2S_MCLKPIN);
 
+  ESP_LOGI(TAG, "Connected. Starting MP3...");
+  audio.connecttohost("http://icecast.omroep.nl/3fm-bb-mp3");
+
+  dac.setSPKvol(40); /* max 63 */
+  dac.setHPvol(32, 32);
+}
+
+void loop() {
+  audio.loop();
+}
+
+```
+
+#### Setup i2c and wm8978 separately
+
+```c++
+#include <Wire.h>
+#include <WM8978.h> /* https://github.com/CelliesProjects/wm8978-esp32 */
+#include <Audio.h>  /* https://github.com/schreibfaul1/ESP32-audioI2S */
+
+/* M5Stack Node I2S pins */
+#define I2S_BCK      5
+#define I2S_WS      13
+#define I2S_DOUT     2
+#define I2S_DIN     34
+
+/* M5Stack WM8978 MCLK gpio number */
+#define I2S_MCLKPIN  0
+
+WM8978 dac;
+Audio audio(I2S_BCK, I2S_WS, I2S_DOUT);
+
+void setup() {
+
+  if (!Wire.begin(21, 22, 400000))
+    ESP_LOGE(TAG, "i2c setup error!");
+
+  if (!dac.begin())
+    ESP_LOGE(TAG, "WM8978 setup error!");
+
+
   WiFi.begin("xxx", "xxx");
   while (!WiFi.isConnected()) {
     delay(10);
   }
+
+  /* Start MCLK */
+  audio.i2s_mclk_pin_select(0);
+
   ESP_LOGI(TAG, "Connected. Starting MP3...");
   audio.connecttohost("http://icecast.omroep.nl/3fm-bb-mp3");
 
@@ -52,6 +105,6 @@ void setup() {
 void loop() {
   audio.loop();
 }
-
 ```
+
 To show `ESP_LOGx` messages on the Serial port, compile with `Tools->Core Debug Level` set to `Info`.

src/WM8978.cpp

@@ -300,21 +300,17 @@ void WM8978::setNoise(uint8_t enable, uint8_t gain)
   Write_Reg(35, regval); //R18,EQ1设置
 }
 
-bool WM8978::begin(const uint8_t sda, const uint8_t scl, const uint32_t frequency) {
-  ESP_LOGD(TAG, "WM8978 I2C init sda=%i scl=%i frequency=%i", sda, scl, frequency);
-  if (!Wire.begin(sda, scl, frequency)) {
-    ESP_LOGD(TAG, "Wire setup error");
-    return false;
-  }
+
+bool WM8978::begin() {
   Wire.beginTransmission(WM8978_ADDR);
-  uint8_t error = Wire.endTransmission();
+  const uint8_t error = Wire.endTransmission();
   if (error) {
-    ESP_LOGD(TAG, "No WM8978 @ I2C address: 0x%X", WM8978_ADDR);
+    ESP_LOGE(TAG, "No WM8978 dac @ i2c address: 0x%X", WM8978_ADDR);
     return false;
   }
-  int err = Init();
+  const int err = Init();
   if (err) {
-    ESP_LOGD(TAG, "WM8978 init err: 0x%X", err);
+    ESP_LOGE(TAG, "WM8978 init err: 0x%X", err);
     return false;
   }
   cfgI2S(2, 0); //Philips 16bit
@@ -333,4 +329,14 @@ bool WM8978::begin(const uint8_t sda, const uint8_t scl, const uint32_t frequenc
   setEQ5(0, 24);
   cfgOutput(1, 0); //Output enabled, bypass disabled
   return true;
-} //begin
+}
+
+bool WM8978::begin(const uint8_t sda, const uint8_t scl, const uint32_t frequency) {
+  ESP_LOGD(TAG, "i2c init sda=%i scl=%i frequency=%i", sda, scl, frequency);
+  if (!Wire.begin(sda, scl, frequency)) {
+    ESP_LOGE(TAG, "Wire setup error sda=%i scl=%i frequency=%i", sda, scl, frequency);
+    return false;
+  }
+  return begin();
+}
+

src/WM8978.h

@@ -35,6 +35,7 @@ class WM8978
   public:
     WM8978() {}
     ~WM8978() {}
+    bool begin(); /* use this function if you want to setup i2c before */
     bool begin(const uint8_t sda, const uint8_t scl, const uint32_t frequency = 100000);
     void cfgADDA(uint8_t dacen, uint8_t adcen);
     void cfgInput(uint8_t micen, uint8_t lineinen, uint8_t auxen);