Hear-it! Solution Kit
5 Embedded Firmware Application
R12UZ0012EG0110 Rev. 1.10
Page 21 of 34
Apr 03, 2017
5.3.1.4 Microphone Input
The microphone input, CN8 is not fitted to the Hear-it! board by default. If the microphone input is to be used in
the streaming application, the CODEC must be configured to enable its internal PGAs (Programmable Gain
Amplifiers) in order to allow the audio signal from the MIC input to be used.
This is achieved by un-commenting the #define ENABLE_MICROPHONE, in the main.h file.
Figure 5-4 : Enabling the MIC input CN8
5.3.2
USB Playback Application
5.3.2.1 File Selection
This sample allows the user to select .wav files from a USB drive attached to the USB Host connector CN9 and
to play the audio on the speaker/headphones. The USB drive must contain a folder called ‘Music’. The Music
folder may hold a maximum of 16 .wav files. Ensure the USB drive contains the ‘Music’ folder as seen in the
figure below and contains .wav files. The available .wav files will be shown on the display connected on PMOD
TM
connector CN2. Use pot R43 and switch SW3 to select the desired track to play.
Figure 5-5 : Music Folder on USB Drive
5.3.2.2 Volume Control Scheme
The sample application by default uses a software attenuation function to control the volume of the audio signal.
It is possible to configure the application to use the CODEC to control the volume. In order to select this,
uncomment the following #define in main.h
Figure 5-6 : Streaming Volume Configuration Selection
Summary of Contents for RX231
Page 34: ...RX231 Group R12UZ0012EG0110 ...
