Telit Wireless Solutions LE910C1-NA, Руководство пользователя по оборудованию

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1VV0301517 - Audio Codec Extension Card - HW User Guide
General description
Rev. 2 Page 13 of 22 2019-12-04
Detailed Usage and Configuration
This section will describe the Audio codec card configuration and jumpers setting for the
various configuration available by software.
2.3.1. Audio Codec Control
The control interface of the Audio Codec is an I2C bus.
The Codec card supports 2 options for interfacing the codec I2C:”
•
Using the dedicated I2C of the Host
• Using GPIO emulated I2C via the Host GPIO’s
2.3.2. Audio Codec Control via dedicated I2C
The extension card default jumpers configuration assumes that the interface used to set
the audio codec configuration is the module dedicated I2C port.
When using this mode, the configuration is sent to the codec via an AT command.
The AT command used to configure the external codec MAX9867 is AT#DVI=0.
When executing this AT command, the module software configures the audio codec as a
slave PCM device through the dedicated I2C interface.
Once codec is configured, an audio call can be established.
2.3.3. Audio Codec configuration via GPIO’s
The MAX9867 can also be configured by the customer independently from the default
software configuration set by sending the AT#DVI=0 command.
This option uses any pair of GPIO’s forming an emulated I2C.
The I2C bus can be connected to any module GPIO pin by a jumper setting.
The LE910C1 software emulates an I2C interface by toggling the GPIO pins according to
the I2C standard protocol (For more information, please refer to the LE910Cx HW User
Guide).
For enabling this option, the jumper settings on the extension card should be changed.
The below example describes how to setup the board for using I2C on GPIO_2 & GPIO_3
•
GPIO_2 acts as I2C_SCL.
•
GPIO_3 acts as I2C_SDA.
The jumpers should be set as follows:
•
Remove jumper shunts from J101, J102.
•
Place a jumper shunt in J103 on pins 5-6.
•
Place a jumper shunt in J104 on pins 3-4.
Once the board is set, the AT#I2CWR command can be used for setting the Audio codec
After sending this command you will be presented with the “>” prompt indicating that the
I2C data bytes should be sent.
After the sequence is sent the CTRL+Z keys should be sent to terminate the command
and send the data.
AT#I2CWR=3,2,30,4,19
>001020000400330000330C0C09092424400060
Cntrl+Z
For reference and details on the AT command syntax, please see the AT commands
reference guide document.
For reference on the Audio Codec registers settings please refer to the Audio Codec
datasheet on Maxim Integrated web site:
https://www.maximintegrated.com/en/products/analog/audio/MAX9867.html