Introduce isChipConnected() method. (#27)

Author: wmarkow

src/VS1053.cpp

@@ -279,4 +279,15 @@ void VS1053::switchToMp3Mode() {
     delay(100);
     LOG("Switched to mp3 mode\n");
     softReset();
-}
+}
+
+/**
+ * A lightweight method to check if VS1053 is correctly wired up (power supply and connection to SPI interface).
+ *
+ * @return true if the chip is wired up correctly
+ */
+bool VS1053::isChipConnected() {
+    uint16_t status = read_register(SCI_STATUS);
+
+    return !(status == 0 || status == 0xFFFF);
+}

src/VS1053.h

@@ -47,6 +47,7 @@ class VS1053 {
     const uint8_t vs1053_chunk_size = 32;
     // SCI Register
     const uint8_t SCI_MODE = 0x0;
+    const uint8_t SCI_STATUS = 0x1;
     const uint8_t SCI_BASS = 0x2;
     const uint8_t SCI_CLOCKF = 0x3;
     const uint8_t SCI_AUDATA = 0x5;
@@ -132,6 +133,8 @@ class VS1053 {
     }
 
     void switchToMp3Mode();
+
+    bool isChipConnected();
 };
 
 #endif