LTE Cat.4 Click (for Europe)

How does it work?

LTE Cat.4 Click is based on the EG95EXGA-128-SGNS, an IoT/M2M-optimized LTE Cat.4 module from Quectel with a receive-diversity feature for European region. Adopting 3GPP Rel. 11 LTE technology delivers maximum data rates up to 150Mbps downlink and 50Mbps uplink. It supports multiple LTE bands (B1/B3/B7/B8/B20/B28), RX diversity for bands B1 and B8, as well as multi-constellation GNSS support for GPS, GLONASS, BeiDou/Compass, Galileo, and QZSS. This module is fully integrated with Internet service protocols such as TCP, UDP, and PPP, making it easy to use with extended AT commands. Based on its broad set of features, this Click board™ is suitable for a wide range of M2M and IoT applications such as industrial routers, industrial PDAs, video surveillance, digital signage, and many others.

Communication between the EG95EXGA-128-SGNS and the host MCU is made through a UART interface, using standard UART RX and TX pins and hardware flow control pins (CTS/RTS/RI – Clear to Send/Ready to Send/Ring Indicator) for efficient data transfer. The module defaults to a communication speed of 115200bps, allowing for seamless data exchange over AT commands. Notably, this module version also features an audio interface, which can be accessed via the I2C interface.

The LTE Cat.4 Click audio interface operates through the MAX9860, a 16-bit mono audio voice codec configurable via the I2C interface. This setup works with a jack on the back of the board designed for CTIA standard headphones, which are commonly used in modern smartphones and feature a combined audio and microphone connector. This standard ensures compatibility with a wide range of headphones and headsets. Additionally, the audio interface supports advanced features such as echo cancellation and noise suppression, enhancing the clarity and quality of voice communications.

The LTE Cat.4 Click also includes a USB Type C connector for both power and data transfer, which is compliant with the USB 2.0 specification (slave only). This interface supports data transfer rates of up to 480Mbps, enabling AT command communication, data transmission, GNSS NMEA sentence output, software debugging, firmware upgrades, and voice-over USB. The board features a USB FW upgrade switch on the back of the board labeled USB BOOT to manage firmware upgrades. This switch has positions 0 for normal operation and 1 for firmware upgrades over USB, ensuring a straightforward upgrade process.

In addition, this Click board™ includes several additional functionalities that enhance its usability and control. The PWR button allows users to easily power the module on or off, while the RESET button provides a quick way to reset the module. These functions can also be controlled digitally via the mikroBUS™ pins PWR and RST, offering greater flexibility. Moreover, these controls have dedicated test points for easier debugging and testing. The board also features two visual indicators to provide real-time status updates. The red NET LED offers feedback on network activity: it flickers slowly when searching for a network, flickers quickly during data transfer, and remains steadily on during voice calls. The yellow STAT LED indicates the module’s power status, which stays off when the module is off and turns on when the module is powered on. The board also includes DBG TX/RX interface test points for UART debug communication, simplifying the development and troubleshooting process.

The board features three u.Fl connectors for GNSS, LTE, and LTE/WCDMA RX-diversity antennas that MIKROE offers, like the LTE Flat Rotation Antenna and Active GPS Antenna combined with an IPEX-SMA cable for flexible and efficient connectivity options. In addition, the user can easily choose the power supply of the GNSS antenna by choosing between 3.3V and 5V on the GNSS ANT jumper. Additionally, the board is equipped with a micro SIM card holder that supports both 1.8V and 3.0V uSIM cards, ensuring compatibility with a wide range of cellular networks and allowing users to select the most appropriate service provider for their particular use case.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. Since the EG95EXGA-128-SGNS module operates at 3.8V, logic-level translators, the TXB0106 and PCA9306, are also used for proper operation and an accurate signal-level translation. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Specifications

Pinout diagram

This table shows how the pinout on LTE Cat.4 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Module Power-ON	PWR	1	AN	PWM	16	RI	Ring Indicator
Reset / ID SEL	RST	2	RST	INT	15	CTS	UART CTS
UART RTS / ID COMM	RTS	3	CS	RX	14	TX	UART TX
	NC	4	SCK	TX	13	RX	UART RX
	NC	5	MISO	SCL	12	SCL	I2C Clock
	NC	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

LTE Cat.4 Click electrical specifications

Software Support

We provide a library for the LTE Cat.4 Click as well as a demo application (example), developed using MIKROE compilers. The demo can run on all the main MIKROE development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on MIKROE github account.

Library Description

This library contains API for LTE Cat.4 Click driver.

Key functions

• ltecat4_set_sim_apn This function sets APN for sim card.

• ltecat4_send_sms_text This function sends text message to a phone number.

• ltecat4_send_cmd This function sends a specified command to the click module.

Example Description

Application example shows device capability of connecting to the network and sending SMS or TCP/UDP messages, answering incoming calls, or retrieving data from GNSS using standard “AT” commands.

void application_task ( void ) 
 { 
     switch ( app_state ) 
     { 
         case LTECAT4_POWER_UP: 
         { 
             if ( LTECAT4_OK == ltecat4_power_up( &ltecat4 ) ) 
             { 
                 app_state = LTECAT4_CONFIG_CONNECTION; 
                 log_printf( &logger, ">>> APP STATE - CONFIG CONNECTION <<<rnn" ); 
             } 
             break; 
         } 
         case LTECAT4_CONFIG_CONNECTION: 
         { 
             if ( LTECAT4_OK == ltecat4_config_connection( &ltecat4 ) ) 
             { 
                 app_state = LTECAT4_CHECK_CONNECTION; 
                 log_printf( &logger, ">>> APP STATE - CHECK CONNECTION <<<rnn" ); 
             } 
             break; 
         } 
         case LTECAT4_CHECK_CONNECTION: 
         { 
             if ( LTECAT4_OK == ltecat4_check_connection( &ltecat4 ) ) 
             { 
                 app_state = LTECAT4_CONFIG_EXAMPLE; 
                 log_printf( &logger, ">>> APP STATE - CONFIG EXAMPLE <<<rnn" ); 
             } 
             break; 
         } 
         case LTECAT4_CONFIG_EXAMPLE: 
         { 
             if ( LTECAT4_OK == ltecat4_config_example( &ltecat4 ) ) 
             { 
                 app_state = LTECAT4_EXAMPLE; 
                 log_printf( &logger, ">>> APP STATE - EXAMPLE <<<rnn" ); 
             } 
             break; 
         } 
         case LTECAT4_EXAMPLE: 
         { 
             ltecat4_example( &ltecat4 ); 
             break; 
         } 
         default: 
         { 
             log_error( &logger, " APP STATE." ); 
             break; 
         } 
     } 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager (recommended), downloaded from our LibStock™ or found on MIKROE github account.

Other MIKROE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.LTECat4

Additional notes and informations

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. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE 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.