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RS Audio Codec

This page provides information and some examples for the use of the RS Audio Codec sub board, based on TI's TLV320 chip. This chip provides a high quality audio link out and in to the mbed with IO including: an amplified stereo headphone out, an stereo line out, a stereo line in and an pre-amped mono microphone input. Such a capable chip opens up a lot of options for high quality audio on mbed. The audio codec board mounted on the RS Animatronic Lab Board

The easiest way to get something working is to load a test wave file (such as this one or this one) onto a flash drive, plug it into the Lab Board and load up this program:

Import programWavPlayer_test

A test program for the WavPlayer class, works on the RS Animatronic Lab Board

Last commit 24 Sep 2012 by Giles Barton-Owen

or just this one:

Import programTLV320_Write_test

A test program for the TLV320, Generates some sine waves.

Last commit 19 Sep 2012 by Giles Barton-Owen

Both programs use the TLV320 library and the I2S library:

Import library
I2S - I2S Class Reference

Public Member Functions

I2S (bool rxtx, PinName sd, PinName ws, PinName clk)
Create a I2S instance.
I2S (bool rxtx, PinName sd)
Create a I2S instance: Only with the serial data line set.
I2S (bool rxtx, PinName sd, PinName ws)
Create a I2S instance: Only with serial data line and word select.
I2S (bool rxtx, PinName sd, bool fourwiremode)
Create a I2S instance: Only with serial data line.
I2S (bool rxtx, PinName sd, PinName ws, bool fourwiremode)
Create a I2S instance: Only with serial data line and word select line.
~I2S ()
Destroy the I2S instance.
void write (char buf[], int len)
Write to the FIFO.
void write (int buf[], int len)
Write to the FIFO.
int read ()
Read the FIFOs contents.
void read (char buf[], int len)
Read from the FIFO.
void read (int buf[], int len)
Read from the FIFO.
int max_fifo_points ()
Get the maximum number of points of data the FIFO could store.
void power (bool pwr)
Switch the peripheral on and off.
void masterslave (bool mastermode)
Switch the peripheral between master and slave.
void wordsize (int words)
Switch the peripheral between different wordsizes.
void mclk_freq (int freq)
Define the mclk frequency.
void frequency (int freq)
Define the sample rate.
void set_interrupt_fifo_level (int level)
Set the level that the fifo interrupts at.
int fifo_level ()
Get the current FIFO level.
int fifo_points ()
Get the current number of samples in the FIFO.
void stereomono (bool stereomode)
Set whether the peripheral is in stereo or mono mode: in mono the perifpheral sends out the same data twice.
void mute ()
Mute the peripheral.
void mute (bool mute_en)
Set the mute status of the peripheral.
void stop ()
Stop the peripheral.
void start ()
Start the peripheral.
bool setup_ok ()
Check the Clock and Pin setup went according to plan.
void attach (void(*fptr)(void))
Attach a function to be called when the FIFO triggers.
template<typename T >
void attach (T *tptr, void(T::*mptr)(void))
Attach a member function to be called when the FIFO triggers.

Import library
TLV320 - TLV320 Class Reference

Public Member Functions

TLV320 (PinName i2c_sda, PinName i2c_scl)
Create an instance of the TLV320 class.
TLV320 (PinName i2c_sda, PinName i2c_scl, bool cs_level)
Create an instance of the TLV320 class.
void power (bool on_off)
Control the power of the device.
void input_select (int input)
Control the input source of the device.
void headphone_volume (float h_volume)
Set the headphone volume.
void linein_volume (float li_volume)
Set the line in pre-amp volume.
void microphone_boost (bool mic_boost)
Turn on/off the microphone pre-amp boost.
void input_mute (bool mute)
Mute the input.
void output_mute (bool mute)
Mute the output.
void input_power (bool on_off)
Turn on/off the input stage.
void output_power (bool on_off)
Turn on/off the output stage.
void wordsize (int words)
Select the word size.
void master (bool master)
Select interface mode: Master or Slave.
void frequency (int freq)
Select the sample rate.
void input_highpass (bool enabled)
Enable the input highpass filter.
void output_softmute (bool enabled)
Enable the output soft mute.
void interface_switch (bool on_off)
Turn on and off the I2S.
void reset ()
Reset the device and settings.
void sidetone (float sidetone_vol)
Set the microphone sidetone volume.
void bypass (bool bypass_en)
Set the analog bypass.
void deemphasis (char code)
Set the deemphasis frequency.
void adc_highpass (bool enable)
Enable the input highpass filter.
void start ()
Start the device sending/recieving etc.
void stop ()
Stop the device sending/recieving etc.
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