LARA-R6 series - Data sheet

UBX-21004391 - R09

Interfaces

Page 14 of 41

C1-Public

2.5.1.1 Multiplexer protocol

LARA-R6 series modules include multiplexer functionality as per 3GPP TS 27.010 [9] on the main

primary UART physical interface. The multiplexer functionality is not supported on the secondary

auxiliary UART physical interface.

The multiplexer functionality is a data link protocol which uses HDLC-like framing and operates

between the module (DCE) and the application processor (DTE), allowing several simultaneous

sessions over the physical link (main primary UART): the user can concurrently use AT interface on

one MUX channel and data communication on another MUX channel.

The following virtual channels are available:

•

Multiplexer control

•

AT commands / data connection

•

GNSS data tunneling

2.5.2 USB interface

LARA-R6 series modules include a USB High-Speed 2.0 compliant interface with a maximum

480 Mbit/s data rate according to the Universal Serial Bus specification revision 2.0 [14]. The module

itself acts as a USB device and can be connected to any compatible USB host.

The USB interface is available for communication with a host application processor (AT commands,

data communication, GNSS tunneling, FW update by means of the FOAT feature), for FW update by

means of the u-blox EasyFlash tool and for diagnostics.

The USB_D+ / USB_D- lines carry the USB data and signaling. The USB interface is automatically

enabled by an external valid USB VBUS voltage applied on the VUSB_DET input pin of the module.

☞ The USB interface of the LARA-R6 series modules is enabled only if an external voltage detectable

as High logic level (see Table 25 for the electrical characteristics) is present at the VUSB_DET

input during the switch-on boot sequence of the module. This configuration can be changed by the

+UUSBDET AT command on all LARA-R6 series modules versions except LARA-R6001D-00B.

The USB interface makes several functions available with various capabilities and purposes, such as:

•

Virtual serial port over USB for AT commands and data communication

•

Virtual serial port over USB for GNSS tunneling

•

Virtual serial port over USB for Diagnostic log

The user can concurrently use AT command interface on one virtual serial port, and packet switched

/ circuit switched data communication on another virtual serial port over USB.

LARA-R6 series modules are compatible with the standard Linux/Android USB kernel drivers.

☞ It is highly recommended to provide access to the VUSB_DET, USB_D+, USB_D- pins for FW

update and for diagnostic purpose, by means of test points directly connected to the pins.

2.5.3 I2C interface

LARA-R6 series modules include an I2C-bus compatible interface (SDA and SCL pins) available to

communicate with an external u-blox GNSS chips / modules, and with external compatible I2C devices

as for example an audio codec: LARA-R6 series module acts as an I2C host which can communicate

with I2C local devices in accordance with the I2C bus specifications [15].

For more details regarding I2C interface usage and the integration with a u-blox GNSS receiver, see

the LARA-R6 series system integration manual [2], GNSS implementation application note [6], and

the I2C and GNSS AT commands description in the u-blox AT commands manual [1].