ReSpeaker 4-Mic Array for Raspberry Pi

ReSpeaker 4-Mic Array

Version pour Raspberry Pi

Montage

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Assurez-vous que les broches sont correctement alignés.

Attention le branchement à chaud peut endommager ReSpeaker .

Veuillez faire l’assemblage avec le Raspberry Pi une fois cette dernière éteint (Power Off)

Step 1.

The AC108 codec is not supported by Pi kernel builds currently, we have to build it manually.

1. Please Make sure running the lastest Raspbian Operating System(debian 9) on Pi. (updated at 2018.6.27)

Step 2.

2. Get the seeed voice card source code.

	sudo apt-get update
	sudo apt-get upgrade
	git clone https://github.com/respeaker/seeed-voicecard.git
	cd seeed-voicecard
	sudo ./install.sh
	reboot

Step 3

3. Then select the headphone jack on Raspberry Pi for audio output:

	sudo raspi-config
	# Select 7 Advanced Options
	# Select A4 Audio
	# Select 1 Force 3.5mm ('headphone') jack
	# Select Finish

Step 4.

4. Check that the sound card name looks like this:

	pi@raspberrypi:~/seeed-voicecard $ arecord -L
	null
		Discard all samples (playback) or generate zero samples (capture)
	playback
	capture
	dmixed
	array
	ac108
	default:CARD=seeed4micvoicec
		seeed-4mic-voicecard,
		Default Audio Device
	sysdefault:CARD=seeed4micvoicec
		seeed-4mic-voicecard,
		Default Audio Device
	dmix:CARD=seeed4micvoicec,DEV=0
		seeed-4mic-voicecard,
		Direct sample mixing device
	dsnoop:CARD=seeed4micvoicec,DEV=0
		seeed-4mic-voicecard,
		Direct sample snooping device
	hw:CARD=seeed4micvoicec,DEV=0
		seeed-4mic-voicecard,
		Direct hardware device without any conversions
	plughw:CARD=seeed4micvoicec,DEV=0
		seeed-4mic-voicecard,
		Hardware device with all software conversions

If we want to change the alsa settings, we can use

	sudo alsactl --file=ac108_asound.state store 

to save it. And when we need to use the settings again, copy it to:

	sudo cp ~/seeed-voicecard/ac108_asound.state /var/lib/alsa/asound.state

Step 5.

5. Open Audacity and select AC108 & 4 channels as input and bcm2835 alsa: - (hw:0:0) as output to test:

	$ sudo apt update
	$ sudo apt install audacity
	$ audacity                      // run audacity

section 7

Step 6. Or we could record with arecord and play with aplay:

	arecord -Dac108 -f S32_LE -r 16000 -c 4 hello.wav    // only support 4 channels
	aplay hello.wav                                      // make sure default device
							     // Audio will come out via audio jack of Raspberry Pi