ADC/DAC software loopback demo
1、Function overview
The main functions of the ADC/DAC software loopback demo of the AUDIO module are: transfer the audio data of the audio sampling (AUDIO_ADC) to the audio playback (AUDIO_DAC) through DMA for playback.
2、Code path
demo path:
\components\demos\media\audio\aud
For the detailed description of the AUDIO ADC/DAC API interface, please refer to the same webpage:
/api-reference/multi_media/bk_aud.html
3、Cli command introduction
The commands supported by the demo are as follows:
Command |
Description |
---|---|
aud_adc_mcp_test {start|stop} |
cpu transfers mic data to dac |
aud_dtmf_mcp_test {start|stop} |
cpu transfers dtmf data to dac |
aud_adc_dma_test {start|stop} |
DMA transfers mic data to dac |
aud_adc_loop_test {start|stop} |
mic data to dac hard loopback |
aud_dtmf_loop_test {start|stop} |
dtmf data to dac hard loopback |
The macro configuration that the demo runs depends on:
Name |
Description |
File |
value |
---|---|---|---|
CONFIG_AUDIO |
Configure the audio function |
|
y |
CONFIG_AUDIO_RISCV_IP_V1_0 |
Configure the audio function |
|
y |
CONFIG_AUDIO_TEST |
Configure the demo function |
|
y |
- Demo runs dependent libraries and drivers:
DMA DMA driver
AUD audio module driver
4、Demo introduction
The steps performed by the demo are as follows:
- 1.execute the test
Uart sends AT command
cpu1 aud_adc_dma_test start
to execute the test- 2.Verification function
Connect the headset to hear the audio captured by the onboard mic
- 3.stop test
Uart sends AT command
cpu1 aud_adc_dma_test stop
to stop the test
Note
For other demos, you can start or stop the test by sending the corresponding commands according to the command table supported by the cli according to the above steps.
Execute the test command, the workflow of the case is shown in the following figure:
5、Detailed configuration and description
AUDIO_ADC performance
- AUDIO_ADC supports two working modes: DTMF and ADC:
DTMF working mode Direct digital mixing generates digital audio signal without mic sampling
ADC working mode ADC sampling of mic input signal, supports simultaneous sampling of up to 2 channels of mic
The sampling rate Fs(bps) supported by AUDIO_ADC:
8K
16K
44.1K
48K
Important
1.ADC working mode supports DMA transfer of mic sampling results
2.DTMF working mode does not support DMA transfer of mixing results, only cpu transfer of mixing results
3.ADC mode and DTMF mode only support one at the same time