Adding SGTL5000_Extended.h

AudioControlSGTL5000_Extended.h

@@ -0,0 +1,40 @@
+
+/* AudioContolSGTL5000_Extended.h
+ *  
+ *  Purpose: Extends the functionality of the AudioControlSGTL5000 from the Teensy Audio Library
+ *  
+ *  Created: Chip Audette, Nov 2016
+ *  
+ *  License: MIT License.  Use at your own risk
+ */
+
+#ifndef _AudioControlSGTL5000_Extended
+#define _AudioControlSGTL5000_Extended
+
+class AudioControlSGTL5000_Extended : public AudioControlSGTL5000
+{
+  public:
+    AudioControlSGTL5000_Extended(void) {};
+    bool micBiasEnable(void) {
+      return micBiasEnable(3.0);
+    }
+    bool micBiasEnable(float volt) {
+      //in the SGTL5000 datasheet see Table 29. CHIP_MIC_CTRL  Register 0x002A
+
+      ///bias resistor is set via bits 9-8 (out of 15-0)
+      uint16_t bias_resistor_setting = 1 << 8;  //set the bit for the registor to enable 2kOhm
+
+      //bias voltage is set via bits 6-4 (out of 15-0)
+      uint16_t  bias_voltage_setting = ((uint16_t)((volt - 1.25) / 0.250 + 0.5)) << 4;
+      
+      //combine the two settings and issue the command
+      return write(0x002A, bias_voltage_setting | bias_resistor_setting);
+    }
+    bool micBiasDisable(void) {
+      //in the SGTL5000 datasheet see Table 29. CHIP_MIC_CTRL  Register 0x002A
+      return write(0x002A, 0x00);
+    }
+};
+
+#endif
+

OpenAudio_ArduinoLibrary.h

@@ -2,3 +2,5 @@
 #include <AudioStream_F32.h>
 #include <AudioConvert_F32.h>
 #include <AudioEffectGain_F32.h>
+#include <AudioControlSGTL5000_Extended.h>
+