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11. Codec Zero Configuration

The IQaudio Codec Zero board uses the Dialog Semiconductor DA7212 codec. The DA7212 allows

the recording of audio from the

board’s built in MEMS microphone, from stereo Phono sockets (AUX

IN), 2x mono external Electret microphones and playback through stereo Phono sockets (AUX OUT)

and mono speaker connector.

Each input and output device has its own

“mixer” allowing the audio levels / volume to be adjusted

independently. Within the codec itself other mixers / switches exist to allow the output to be

Mono’d

for single speaker output, signals may also be inverted and there is a 5 band Equaliser to adjust

certain frequency bands. These settings can be controlled through alsamixer interactively or

programatically.

It is important to note that the AUX IN and AUX OUT are both 1vRMS. It may be necessary to adjust

the AUX

IN’s mixer to ensure the input signal doesn’t saturate the ADCs. (Analogue to Digital

Convertors). Similarly, the output mixers may been to be adjusted to get the best possible output.

Codec Zero features:

• High performance 24-bit audio codec

• Supports common audio sample rates between 8-96kHz

• Built in MEMS microphone (Mic2)

• Mono Electret microphone (Mic2 left)

• Automatic MEMS disabling on Mic2 insert detect

• Supports additional (no fit) Mono Electret microphone (Mic1 right)

• Stereo auxiliary input channel (AUX IN) - PHONO/RCA connectors

• Stereo auxiliary output channel (Headphone / AUX OUT) - 3.5mm Stereo jack

• Flexible analog and digital mixing paths

• DSP for ALC (Automatic Level Control)

• 5-band EQ (Equalisation)

• Mono line-out / mini speaker driver: 1.2W @ 5V, THD<10%,

R=8Ω

We’ve created a set of preconfigured scripts (loadable ALSA settings) on our GitHub site.

https://github.com/iqaudio/Pi-Codec - These cover several use cases such as:

• Mono MEMS mic recording, mono speaker playback

• Mono MEMS mic recording, mono AUX OUT playback

• Stereo AUX IN recording, stereo AUX OUT playback

• Stereo MIC1/MIC2 recording, stereo AUX OUT playback

NOTE: THE CODEC

BOARD’S DA7212 CHIP NEEDS TO KNOW WHAT IS INPUT AND WHAT IS

OUTPUT AT EACH POWER CYCLE FOR IT TO OPERATE SUCCESSFULLY. We suggest your