NXP Semiconductors i.MX 8MIC-RPI-MX8 User manual

Quick Start Guide
i.MX 8MIC-RPI-MX8 Board

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ABOUT THE 8MIC-RPI-MX8 BOARD
Quick Start Guide
The 8MIC-RPI-MX8 accessory board is designed for voice enabled application
prototyping and development on the i.MX 8M family. The board plugs directly into the
40-pin expansion connector on the i.MX 8M Mini and Nano EVK’s.
The specific layout of the eight microphones allows for various microphone
configurations to be evaluated and tailored to specific use-cases such as smart speaker,
or smart display.
FEATURES
• 8 PDM Microphones
• 8 monochrome LEDs
• 4 multi-color LEDs
• 2 status LEDs
• 4 pushbuttons
• Microphone Mute Switch
• Microphone geometry switch

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GET TO KNOW THE i.MX 8M MINI EVK
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Figure 1: Top view i.MX 8M Mini DDR4 EVK board
On/Off ResetOn/Off Reset
IR ReceiverIR Receiver
Power SwitchPower Switch
JTAGJTAG
ExpansionExpansion
ConnectorConnector
Note: Pin 1Note: Pin 1
locationlocation
Wi-Fi/BT AntennaWi-Fi/BT Antenna
Display: MIPI-DSIDisplay: MIPI-DSI
Camera: MIPI-CSICamera: MIPI-CSI
CPU BoardCPU Board
BOOT SwitchesBOOT Switches
II22C ConnectorC Connector
USB MicroBUSB MicroB
Debug PortDebug Port
Type CType C
Port1Port1
Type CType C
Port2Port2
EthernetEthernet AudioAudio
LineoutLineout

Quick Start Guide
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GET TO KNOW THE i.MX 8M 8MIC BOARD (8MIC-RPI-MX8)
Figure 2: Front View of the 8MIC Board
8 microphones8 microphones
and UI LEDsand UI LEDs
Board PowerBoard Power
LEDLED
MIC_SELMIC_SEL
switchswitch
Mic MuteMic Mute
LEDLED
Mic geometryMic geometry
change switchchange switch
4 UI push4 UI push
buttonsbuttons
4 Multi-4 Multi-
color LEDscolor LEDs
Note: Pin 1Note: Pin 1
locationlocation

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GET TO KNOW THE i.MX 8M 8MIC BOARD (8MIC-RPI-MX8) CONTINUED
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Figure 2: Back View of the 8MIC Board
Note: Pin 1Note: Pin 1
locationlocation

Quick Start Guide
MICROPHONE ARRAY CONFIGURATIONS
6
1
7 8
2 2
3
4
56
1
4
Default Configuration
1
7
3
4
1
7
4
5
1
7
3
5
6
22
1
3
4
56
2

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GETTING STARTED
Unpack the Kit
This document assumes you are familiar
with the i.MX 8M Mini EVK. If unfamiliar,
please refer to the i.MX 8M Mini EVK
Quick Start Guides at www.nxp.com/
imx8mmini.
Download Software and Tools
Installation software and documentation
are available at www.nxp.com/
imx8mminievk. The following are available
on the website:
Table 2 Software and Tools
ITEM DESCRIPTION
Documentation
• Schematics, layout and Gerber files
• Quick Start Guide
• Hardware Design Guide
Software
Development Linux BSPs, Android BSPs
Demo Images
Copy of the latest Linux and Android BSP
images that are available to program on
the SD Card. i.MX 8M Mini software can
be found at www.nxp.com/imxsw.
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Quick Start Guide
SETTING UP THE SYSTEM
The following will describe how to run the pre-loaded Android image on the i.MX 8M
Mini DDR4 EVK.
1Connect the
Boards
The 8MIC-RPI-MX8 connects directly to
the EVK through the 40-pin accessory
board connector. Ensure that pin 1 of the
8MIC-RPI-MX8 is aligned with pin 1 on the
EVK J1001. The picture to the right shows
the correct orientation.
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Note: Pin 1Note: Pin 1
locationlocation

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SETTING UP THE SYSTEM CONTINUED
2Connect the
Cables
Connect the micro-B end of a USB cable into debug port J1701. Connect the other
end of the cable to a PC acting as a host terminal. Connect the USB Type-C plug of
the Power Supply to J302 (USB Type-C Port2), then power up the board using switch
SW101. Use only J302 for power delivery to the board.
3Record
Audio
At the linux command line in the shell terminal you can use the arecord command to
record audio. The following command will record a 5-second long .wav file on all 8
microphone channels at 48kHz sampling rate and 16-bits.
% arecord -D hw:3,0 -c 8 -f S16_LE -r 48000 -d 5 sample.wav
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Quick Start Guide
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4Playback
Audio
At the linux command line in the shell terminal you can use the aplay command to
playback audio.
First list the available playback devices:
% aplay -l
SETTING UP THE SYSTEM CONTINUED

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SETTING UP THE SYSTEM CONTINUED
On the EVK the wm8524audio is the audio codec which drives the line-out jack. To
play the sample.wav audio through that port the following command should be
issued:
% aplay -Dplughw:1,0 sample.wav
5Storage
• The 8MIC board should be stored in a dust free container or ESD bag. The
microphones may be damaged by dust particles entering the microphone port hole.
• If the EVK and 8MIC board are stored on a desk top it would be best to invert the
boards to prevent dust contamination.

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NXP and the NXP logo are trademarks of NXP B.V. All other product or service names are the property of
their respective owners. © 2020 NXP B.V.
Document Number: IMX8MICQSG REV 0
SUPPORT
Visit www.nxp.com/support for a list
of phone numbers within your region.
WARRANTY
Visit www.nxp.com/warranty for
complete warranty information.
ADDITIONAL INFORMATION