DA7212 Audio Codec HAT

I. Introduction

1.1 Product Overview

Raspberry Pi DA7212 Audio Codec Expansion Board – I2S Audio Sound Card with Rich Audio Interfaces

The DA7212 Audio Codec HAT is an audio expansion board for the Raspberry Pi, connecting via the 40-pin GPIO interface. It features the DA7212 as its core audio codec. The board is equipped with dual onboard microphones, a 3.5mm AUX recording input, a 3.5mm TRRS headphone jack, mono speaker output, stereo speaker output, a volume adjustment knob, a user button, status LEDs, and HAT EEPROM. It is designed for audio playback, recording, headphone/speaker switching, AUX input capture, and basic human-machine interaction.

1.2 Product Features

• Utilizes the DA7212 stereo codec chip with I2S audio transmission and I2C control interfaces.
• Rich audio input options: Dual onboard microphones, CTIA headset microphone input, and 3.5mm AUX analog audio input.
• Multiple audio outputs: Supports 3.5mm TRRS headphone output, mono speaker output, and stereo speaker output.
• Onboard volume adjustment knob for easy hardware-level volume control of TRRS headphone and stereo speaker outputs.
• Onboard user-configurable LEDs and button for easy human-machine interaction.
• Designed with 40-pin GPIO expansion header for compatibility with Raspberry Pi series boards.

1.3 Product Specifications

II. Usage

2.1 Resource Overview

1. Mono Speaker Output
2. 3.5mm AUX Recording Input Jack
3. 3.5mm TRRS Headphone Output Jack
4. Stereo Speaker Output (PH2.0 4P)
5. Onboard Microphone 1
6. User Button (Connected to GPIO27)
7. Volume Adjustment Knob (for TRRS headphone and stereo speaker outputs)
8. Onboard Status LEDs: PWR (3.3V power indicator), D2 (Blue LED, connected to GPIO24), D1 (Green LED, connected to GPIO23)
9. Onboard Microphone 2

2.2. Installation Guide

IMPORTANT NOTES:

1. This board occupies I2C address 0x1A on the I2C1 bus.
2. The TRRS headphone jack supports CTIA standard headsets. When a headset is connected:

• The onboard PH2.0 4P stereo speaker output is automatically muted, and audio is routed to the headphone.
• The onboard microphones are disabled, and the recording input automatically switches to the headset's microphone.

2.2.1. Driver Installation

1. Download the audio test driver file from the "Test Driver" section of this WIKI.
2. Unzip the file using the command: unzip da7212-drv.zip
3. Navigate to the extracted folder: cd da7212-drv/driver
4. Install the driver by running: sudo ./install.sh

2.2.2. Audio Playback Test

Connect mono and stereo speakers to the board, then run the following command in the terminal to play an MP3 file:

sg-audio-test mp3 apologize.mp3

The apologize.mp3 in the command is the MP3 file name. You can replace it with any other audio file as needed. For example, to play aaa.mp3, use the command:

sg-audio-test mp3 aaa.mp3

To play a WAV file, you can use:

sg-audio-test hp ruyuan.wav

During playback, you can adjust the output volume using the onboard volume knob. If you plug headphones into the TRRS headphone jack, the stereo speakers will be automatically muted, and audio will be routed to the headphones.

You can also use the following command to play a WAV file through the mono speaker:

sg-audio-test spk ruyuan.wav

(You can replace it with any other WAV file.)

To adjust the mono speaker volume, open another terminal and use the command:

sg-audio volume spk 55

The volume range is 0 to 63.

2.2.3. Recording Test

Note: The onboard microphones are disabled when a headset with a microphone is plugged into the TRRS jack. The recording input will automatically switch to the headset's microphone.

• Headset Microphone Recording:

Plug in a CTIA-compatible headset with a microphone, then run the following command to test headset microphone recording:

sg-audio-test headset-mic

This command will record audio for 10 seconds, then automatically play back the recorded audio.

• Onboard Microphone Recording:

Unplug any headset from the TRRS jack, then run the following command to test onboard microphone recording:

sg-audio-test onboard-mic

This command will record audio for 10 seconds using the onboard microphones, then automatically play back the recorded audio.

• AUX Input Recording:

Connect an AUX audio cable to the AUX IN jack, and play audio from the other end (e.g., from a computer or smartphone). On the Raspberry Pi side, run the following command:

sg-audio-test aux

This command will record the AUX input for 10 seconds, then automatically play back the recorded audio.

• Extended Duration Recording:

If you need to record for a different duration, you can set the SG_AUDIO_RECORD_SECONDS environment variable before running the command. For example, to set the recording time to 36000 seconds (10 hours):

Onboard Mic Recording:SG_AUDIO_RECORD_SECONDS=36000 sg-audio-test onboard-mic

AUX Recording:SG_AUDIO_RECORD_SECONDS=36000 sg-audio-test aux

Headset Mic Recording:SG_AUDIO_RECORD_SECONDS=36000 sg-audio-test headset-mic

During the recording process, press Ctrl+C to stop recording early. The recorded audio files will be saved in the /tmp/ directory:

• Onboard Mic: /tmp/sg_onboard_mic_two_mics_diff_48k_s16.wav
• AUX: /tmp/sg_aux_48k_s16.wav
• Headset Mic: /tmp/sg_headset_mic_fixed_48k_s16.wav

• LED Test:

Run the following command to test the two onboard LEDs (D1 - Green, D2 - Blue):

sg-audio led all blink 5

During the command execution, both LEDs will blink simultaneously 5 times and then turn off.

• Button Test:

Run the following command to test the user button on the right side of the board:

sg-audio button wait 10

During the 10-second wait period, pressing the button will display a confirmation message indicating that the button has been pressed.

2.2.5. Test Commands

For more test commands, please refer to Table 2-1 and Table 2-2 below.

sg-audio command

3. Resources

3.1. Schematic Diagram

3.2. Test Driver