FAQ_MA35D1_Adjust Headphone Sound

[yhcheng3]

Question :

How to Adjust Headphone Volume?


Answer.

There are two methods for modifying volume:

1. Use the “amixer” command to set the headphone volume.
   When the development environment is Yocto project (QT5), amixer is used by default. If not, the development environment is buildroot, and users need to enable amixer in menucofig. (refer to Figure 1)

   

   Enable amixer in menucofig

   figure1.png (62.25 KiB) Viewed 4254 times

   
   Set Headphone volume by “amixer” or “alsamixer”, refer to Figure 2.

   Code: Select all

   amixer set Headphone 70%

   

   Set the volume on the command line

   figure2.png (28.74 KiB) Viewed 4254 times

   
   Info:
   amixer controls：show all control item as follows:
   amixer contents：view all interfaces of the sound card driver
   .
   .
   .
2. Modify the default value of the codec driver:
   Modify the value of the register in nau8822.c(Nau8822.c(sound\soc\codecs)) and the default value is 0x39(the gain is 0db).
   

   Code: Select all

           {NAU8822_REG_LSPKOUT_VOLUME, 0x0039},
           {NAU8822_REG_RSPKOUT_VOLUME, 0x0039}

   The 0x003f is the maximum volume. The modification method is as follows:
   change

   Code: Select all

           { NAU8822_REG_LHP_VOLUME, 0x0039 },
   	{ NAU8822_REG_RHP_VOLUME, 0x0039 },

   to

   Code: Select all

   	{ NAU8822_REG_LHP_VOLUME, 0x003f },
   	{ NAU8822_REG_RHP_VOLUME, 0x003f },

#MA35D1 #headphone sound #volume #sound
.