GNSS 13 Click

How does it work?

GNSS 13 Click is based on the LG77LICMD, a multi-constellation GNSS module with low power consumption from Quectel Wireless Solutions. It supports concurrent reception of up to three GNSS systems – GPS, GLONASS (or BeiDou), and Galileo, and SBAS signals. Compared with single GPS systems, enabling multiple GNSS systems increases the number of visible satellites, reduces the time to a first fix, and improves positioning accuracy, especially in GNSS-hostile environments. By combining EASY™ (Embedded Assist System), an advanced AGNSS feature, with GLP (GNSS Low Power) low power mode, the LG77LICMD achieves high performance, low power consumption, and fully meets industrial standards.

The EASY™ technology allows the LG77LICMD to automatically calculate and predict orbits by using the ephemeris data (of up to 3 days duration) stored in the internal RAM. As a result, the GNSS 13 Click can acquire a fixed position quickly, even at lower signal levels. With the GLP technology, on the other hand, the LG77LICMD can adaptively adjust the ON/OFF time based on the environmental and motion conditions to achieve a balance between positioning accuracy and power consumption.

This Click board™ comes with a configurable host interface that allows communication with MCU using the selected interface. The LG77LICMD can communicate with MCU using the UART interface with commonly used UART RX and TX pins as its default communication protocol operating at 115200bps to transmit and exchange data with the host MCU or using the optional I2C interface. The I2C interface is compatible with the Fast-Mode allowing a maximum bit rate of 400kbit/s. Since the sensor for operation requires a logic voltage level of 1.8V, this Click board™ also features the TLV700, a 1.8V LDO, and NVT2008 voltage-level translator. The UART and I2C bus lines are routed to the voltage-level translators allowing this Click board™ to work with 3.3V MCU properly.

In addition to all these features, this board has a WUP pin for waking up the module from Backup mode, a general reset feature, as well as several unpopulated headers such as 3DF to indicate successful positioning, a JAM pin to indicate whether there is any signal jamming, and ANT header with OK and OFF pins for active antenna status detection purposes. GNSS 13 Click possesses the SMA antenna connector on which an appropriate active antenna connects that MIKROE has in its offer for improved range and received signal strength. Also, in the case of the primary supply failure, the module can use a backup supply voltage from a connected battery if you need the Click board™ to be a standalone device. In addition to precise positioning, the GNSS 13 Click also has an accurate timing signal indicated through a red LED indicator marked as PPS.

This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing 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 GNSS 13 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
	NC	1	AN	PWM	16	WUP	Module Wake-Up
Reset	RST	2	RST	INT	15	NC
	NC	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	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

GNSS 13 Click electrical specifications

Software Support

We provide a library for the GNSS 13 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 GNSS 13 Click driver.

Key functions

• gnss13_generic_read This function reads a desired number of data bytes from the module.

• gnss13_parse_gngga This function parses the GNGGA data from the read response buffer.

• gnss13_clear_ring_buffers This function clears UART tx and rx ring buffers.

Example Description

This example demonstrates the use of GNSS 13 Click boards™ by reading and displaying the GPS coordinates.

void application_task ( void ) 
 { 
     if ( GNSS13_OK == gnss13_process( &gnss13 ) ) 
     { 
         if ( PROCESS_BUFFER_SIZE == app_buf_len ) 
         { 
             gnss13_parser_application( &gnss13, app_buf ); 
         } 
     } 
 }

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.GNSS13

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.