4G LTE-APJ click (for Asia Pacific)
PID: MIKROE‐3351
Weight: 36 g
4G LTE‐APJ click is an LTE Cat 1 / UMTS multimodecellular network solution,
featuring the compact LARA-R2 series modem from u-blox. This module
supports up to three LTE bands and one UMTS band. It also features a full
range of options for the high speed cellular networking and communication,
such as the network indication, full embedded TCP/UDP stack, HTTP and
HTTPS transfer protocols, IPv4/IPv6 dual-stack support, secondary antenna
for the RX diversity, antenna detection, jamming signal detection, embedded
TLS 1.2 protocol for the improved security and more. 4G LARA click can
achieve data rates up to 10.3 Mbps/5.2 Mbps (downlink/uplink).
The LARA‐R280 module is fully qualified and certified solution which simplifies
the design and cuts time to market. It is perfectly suited for a wide range of
medium to high-speed M2M applications, such as the smart energy
gateways, remote access video cameras, digital signage, telehealth,
telematics, and similar applications which rely on a cellular network
connection.
Note: The 4G LTE click versions for other regions and operators are also
available.
How does it work?
4G LTE click is equipped with the compact LARA-R2 series modem from ublox. There are several 4G LTE click boards which covers different regions
using different modules, as: North America - Verizon featuring LARA-R204,
North America – AT&T featuring LARA-R202, Asia Pacific featuring LARAR280, Europe featuring LARA-R211. The main difference between these
modules are the supported frequency bands, compliant with the regulations
for each region. A complete list of supported bands for each module, along
with other relevant info about the module itself, can be found in the LARAR2 series modem datasheet.
LARA-R2 series modem is the main component of the click board and it
consists of a number of internal blocks or sections, such as antenna
switching and signal conditioning section, RF transceiver section, memory,
power management, and most importantly - the cellular baseband
processor. This section contains the logic necessary for managing the other
sections and provides the interface to the host MCU. This interface consists
of several lines used to report the antenna status, sim card status, UART
interface lines, reset line, USB interface lines... These lines are routed to the
respective elements of the click board.
The LARA-R2 series module has to be powered with a clean and stable
power supply. The voltage needed for the module to work properly is about
4V and it is derived from the 5V mikroBUS™ rail, through the MCP1826, a
1A low drop output (LDO) regulator from Microchip. Although the LARA-R2
series module is a low power device, the cellular network modules, in
general, are notorious for their high power consumption, so the 1A LDO had
to be used.
Digital sections of the LARA-R2 series are internally supplied by 1.8V, so it is
necessary to condition the communication bus lines which connect the host
MCU with the module. For this reason, another small LDO is used, providing
the needed reference voltage for one side of the TXB0106, a 6bit
bidirectional level shifting and voltage translator with automatic direction
sensing, from Texas Instruments. The reference voltage for the other side of
the level shifter is taken from the onboard SMD jumper, labeled as PWR SEL.
This jumper is used to select between 3.3V and 5V from the mikroBUS™,
depending on the used MCU type and its logic voltage level requirements.
The UART bus of the LARA-R2 series module is connected to one side of the
level shifter, while the other side (shifted) is connected to the respective
mikroBUS™ UART pins. However, the LARA-R2 series module is designed as
the traditional DCE device (Data Communication Equipment) offering the full
UART pin count, including the hardware flow control pins (CTS, RTS). These
pins are routed to the mikroBUS™ CS (RTS) and the INT pin (CTS) and can
be used in the MCU software if the hardware flow control is needed. The RI
pin is the ringing indicator, and it is routed to the mikroBUS™ PWM pin.
Another set of modem control pins is routed to the mikroBUS™ pins, via the
level shifter: RI is the ringing indicator pin, and it is routed to the
mikroBUS™ PWM pin. This pin indicates the incoming call.
The STAT pin is used to signalize the network connection status. This pin is
routed both to the mikroBUS™ AN pin through the level shifter, and the
yellow LED used to visually indicate the status of the network connection.
The transmitting status is indicated by the red TX LED, next to the STAT
LED.
The PWRKEY pin is routed to the mikroBUS™ RST pin, and it is used during
the power-up sequence. A low pulse on this pin will power up the device if
the valid supply voltage is provided. To properly detach from the network and store
the working parameters in its non‐volatile memory, the module should be safely powered
off by issuing the AT+CPWROFF command, before disconnecting the power source.
One distinctive feature of the E-UTRA physical radio layer used in LTE
cellular networks is using the spatial multiplexing antenna technology which
allows more than one antenna to be used for better reception of the specific
frequency channel. Besides the primary TX/RX antenna, this click uses a
secondary diversity RX antenna, which allows better signal reception.
4G LTE click is equipped with the micro USB connector. It allows the module
to be powered and configured by a personal computer (PC). u-blox company
offers a software suite that can be used to configure the LARA-R2 series
module.
The Micro SIM card holder on the back of the click board™ is used to install a
SIM card. This device can’t be used without the valid SIM card, which allows
connection to the cellular network. Both 1.8V and 3V SIM card types are
supported.
Free u-blox software
u‐blox offers m‐center, a free evaluation software for all their cellular modules. It has an
easy‐to‐use graphical interface and can be used to configure the module and save changes
to the EPROM. It is possible to view and edit SIM directory entries, send text messages, and
communicate with the wireless module using AT commands.
4G LTE explained
Simply put, 4G is the fourth generation of the cellular network
standard. It does not support traditional circuit-switched telephony service,
it only supports the IP based communication, such as the IP telephony.
LTE (Long Term Evolution) technology, or 4G LTE as it is most commonly
called, has been categorized as a 4G technology just recently. LTE has
several different User Equipment (UE) categories defined. LARA-R
modules are categorized as the LTE Cat 1 device.
If you are not familiar with cellular network standards and protocols and are not sure
whether you need GSM or 3G or 4G, read our learn.mikroe.com article about 2G/3G/4G to
get a better understanding.
Specifications
Type
GSM
Applications
Medium to high speed M2M applications, such as smart energy
gateways, remote access video cameras, digital signage,
telehealth, telematics, and similar applications which can benefit
from cellular network access
On-board
modules
LARA-R280 cellular module from u-blox
Key Features
Data rates of up to 10.3 Mb/s for download and up to 5.2 Mb/s
for upload, micro SIM card socket, dual SMA antenna
connectors, micro USB connector, network detection, jamming
detection, integrated data transfer protocols...
Interface
UART,USB
Input
Voltage
3.3V,5V
Click board
size
L (57.15 x 25.4 mm)
Pinout diagram
This table shows how the pinout on 4G LTE‐APJ click corresponds to the
pinout on the mikroBUS™ socket (the latter shown in the two middle
columns).
Notes
Pin
Pin
Notes
Module status
STA
1
AN
PWM
16
RI
Ring indicator
Power up
module
PWK
2
RST
INT
15
CTS
UART Clear to
send
UART Ready to
send
RTS
3
CS
RX
14
TXD
UART Transmit
data
NC
4
SCK
TX
13
RXD
UART Receive
data
NC
5
MISO
SCL
12
NC
NC
6
MOSI
SDA
11
NC
+3.3V
7
3.3V
5V
10
+5V
Power supply
GND
8
GND
GND
9
GND
Ground
Power supply
Ground
Onboard settings and indicators
Label
PWR
TX
STAT
JP1
Name
Default
Description
PWR
-
Power LED indicator
TX
-
Transmit activity indicator
STAT
-
Network status indicator
PWR SEL
Left
Logic voltage level selection: left position 3.3V, right
position 5V
Software support
We provide a library for LTE-APJ click on our Libstock page, as well as a
demo application (example), developed using MikroElektronika compilers
and mikroSDK. The provided click library is mikroSDK standard compliant.
The demo application can run on all the main MikroElektronika
development boards.
Library Description
The library carries generic command parser adopted for AT command based
modules. Generic parser.
Key functions:
c4glte_cmdSingle - Sends the provided command to the module.
c4glte_setHandler - Handler assignation to the provided command.
c4glte_modulePower - Turns on the module.
Examples Description
Example demo application waits for the call. After the call is received the
parser will get a hangup call.
This code snippet shows how generic parser should be properly initialized.
Before initialization, the module must be turned on and in addition to this,
the hardware
flow control should also be turned on.
The first command negotiates baud rate with the module.
The second command turns echo off.
The third command enables hardware flow control - necessary in case of UART polling.
The fourth command sets up the default message format.
void applicationInit()
{
// MODULE POWER ON
c4glte_hfcEnable( true );
c4glte_modulePower( true );
// MODULE INIT
c4glte_cmdSingle( "AT" );
c4glte_cmdSingle( "ATE0" );
c4glte_cmdSingle( "AT+IFC=2,2" );
c4glte_cmdSingle( "AT+CMGF=1" );
}
Along with the demo application, timer initialization functions are provided.
Note that timer is configured according to the default development system
and MCUs, changing the system or MCU may require an update of timer init
and timer ISR functions.
The full application code, and ready to use projects can be found on
our Libstock page.
Other mikroE Libraries used in the example:
String
Conversions
Additional notes and information
Depending on the development board you are using, you may need USB
UART click, USB UART 2 click or RS232 click to connect to your PC, for
development systems with no UART to USB interface available on the board.
The terminal available in all MikroElektronika compilers, or any other
terminal application of your choice, can be used to read the message.
mikroSDK
This click board is supported with mikroSDK - MikroElektronika Software
Development Kit. To ensure proper operation of mikroSDK compliant click
board demo applications, mikroSDK should be downloaded from
the LibStock and installed for the compiler you are using.
For more information about mikroSDK, visit the official page.
https://www.mikroe.com/4g‐lte‐apj‐click/2‐14‐19