User Manual

SARA-R4 series-AT commands manual
UBX-17003787 - R16

24I
2
C
Page 293 of 401
24I
2
C
24.1Introduction
The I
2
C AT commands support communication with more than one connected device via one of the controllers,
but require opening and closing a logical channel for each connected device. Only one logical channel at a time
can be opened.
The availability and hardware description of the I
2
C interfaces are out of the scope of this document and
are described in a separate document. Refer to the corresponding module System Integration Manual.
The procedure for communicating with two different devices is:
• Open the logical channel for device1 (with AT+UI2CO)
• Read/write to/from device1 (with AT+UI2CR, AT+UI2CW and +UI2CREGR)
• Close the logical channel for device1 (with AT+UI2CC)
• Open the logical channel for device2 (with AT+UI2CO)
• Read/write to/from device2 (with AT+UI2CR, AT+UI2CW and +UI2CREGR)
• Close the logical channel for device2 (with AT+UI2CC)
Once the controller has been configured, it is possible to start I
2
C communication (read/write) with I
2
C slave
peripherals.
The I
2
C controllers available on the u-blox cellular modules module work only in Master Mode so they can
be connected to slave devices only.
In case of a controller/device malfunction, the command's response is only "ERROR".
24.2I
2
C open logical channel +UI2CO
+UI2CO
SARA-R410M-02B SARA-R410M-52B SARA-R410M-63B SARA-R410M-73B SARA-R410M-83B
SARA-R412M
Modules
SARA-N4
Syntax PIN required Settings saved Can be aborted Response time Error referenceAttributes
full No No No - +CME Error
24.2.1Description
Changes the hardware and logical configuration of the selected I
2
C controller.
It is only possible to configure the I
2
C controller in Master Mode.
This command selects:
• The controller available in the u-blox cellular module
• The bus mode type
• The bit rate
• The address size (7-10 bit address)
• The slave device address
Once the selected controller has been configured, a logical channel between it and the selected slave device is
set up and there is no need to further specify it. All the following I
2
C write, read and close commands refer to
the currently opened logical channel. It is not possible to use the I
2
C write, read and open commands for writing
or reading to/from a different slave device without first closing the I
2
C logical channel.
24.2.2Syntax
Type Syntax Response Example
Set AT+UI2CO=<I2C_controller_
number>,<bus_mode>,<bit_rate>,
<device_address>,<address_width>
OK AT+UI2CO=1,0,0,0x42,0
OK