Quick start guide for the SAM WM8731 module

This is the quick start guide for the WM8731 Audio Codec, with step-by-step instructions on how to configure and use the driver in a selection of use cases.

The use cases contain several code fragments. The code fragments in the steps for setup can be copied into a custom initialization function, while the steps for usage can be copied into, e.g., the main application function.

WM8731 use cases

• Basic use case - Configurate the WM8731 to Basic use case - Configurate the WM8731 to DAC mode

Basic use case - Configurate the WM8731 to

DAC mode In this use case, the WM8731 module is configured to DAC mode with I2S audio interface.

Setup

Prerequisites

1. General Purpose I/O Management (gpio)

Code

The following function needs to be added to the user application, to configurate the TWI interface.

static void init_twi_wm8731(void)
{
     twi_options_t opt;

    opt.master_clk = sysclk_get_peripheral_hz();
    opt.speed       = TWI_WM8731_CLK;
    opt.chip        = WM8731_SLAVE_ADDRESS;
    twi_master_setup(TWI_WM8731, &opt);
}

Workflow

1. reset the WM8731:

   • wm8731_reset(); 

2. Select the WM8731 DAC:

   • wm8731_dac_select(1); 

3. Set the WM8731 to usb mode and 48K DAC:

   • wm8731_set_sampling_control(1,0,0); 

4. Set the WM8731 audio interface to I2S mode:

   • ul_value = WM8731_REG_DIGITAL_AUDIO_INTERFACE_FORMAT_I2S;

   • wm8731_set_digital_audio_data_bit_length(ul_value); 

5. Set the WM8731 audio data bit length to 16bit:

   • ul_value = WM8731_REG_DIGITAL_AUDIO_INTERFACE_FORMAT_IWL_16_BIT;

   • wm8731_set_digital_audio_data_bit_length(ul_value); 

6. Disable the WM8731 DAC soft mute:

   • wm8731_set_dac_soft_mute(0); 

7. Power up the WM8731 DAC:

   • wm8731_power_mode_dac(); 

8. Active the WM8731:

   • wm8731_set_active(1);