GNSS 3 Click

How does it work?

GNSS 3 Click is based on the SIM33ELA module, a standalone or A-GPS receiver with a built-in chip antenna from a SIMCom. The SIM33ELA supports only the L1 band with 33 tracking and 99 acquisition channels. The module provides complete signal processing from antenna input to host port in either NMEA messages with the maximum update rate of 10Hz. The module is an ultra-low tracking power consumption device with a high sensitivity of -165dBm while tracking and -147dBm in acquisition mode with fast re-acquisition time. The greater number of visible satellites increases positioning accuracy (<2.5m CEP) and decreases acquisition time (<1.5s TTFF with a warm start). GNSS 3 Click supports anti-jamming, better positioning under weak signal conditions with onboard LNA, and 12 multi-tone active interference cancellers.

The SIM33ELA supports EPO (Extended Prediction Orbit) data service that can predict 7/14/31-day orbit to customers, with occasional downloads from the EPO server. The information like ephemeris, almanac, rough last position and time, the satellite status, and optional time synchronization will reduce TTFF and can be uploaded to the SIM33ELA module by the host side. EASY (Embedded Assistant System) mode predicts satellite navigation messages from the received ephemeris. The module also supports DGPS SBAS (Satellite Based Augmentation System) and RTCM, where only one mode can be used at a time. The SBAS depends on the user’s continent.

The SIM33ELA uses the UART interface with commonly used UART RX and TX pins as its default communication protocol for communication with the host microcontroller. It operates at 115200bps by default configuration to transmit and exchange data. In addition, this Click board™ features other functions accessible through mikroBUS™ signals, such as Reset (RST) for resetting the device and INT pin that could control the module coming into or waking up from Sleep mode.

In addition to the possibility of using the built-in chip antenna, this Click board™ can also use an external active antenna (https://www.mikroe.com/accessories/antennas) offered by Mikroe, thanks to the onboard n.FL connector and ANT SEL solder jumper set to INT or EXT position. In addition to precise positioning, the GNSS 3 Click also has an accurate timing signal indicated via a red LED indicator marked as PPS, the successful positioning indicated by a yellow LED indicator marked as FIX, and the green PWR LED, which acts as a wake-up indicator.

This Click board™ can only be operated from a 3.3V logic voltage level. Therefore, the board must perform appropriate logic voltage 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 GNSS3 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	NC
Reset	RST	2	RST	INT	15	NC
Wake-Up Interrupt	INT	3	CS	RX	14	TX	UART TX
	NC	4	SCK	TX	13	RX	UART RX
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

GNSS3 Click electrical specifications

Software Support

We provide a library for the GNSS3 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 GNSS3 Click driver.

Key functions

• GNSS 3 parse GNGGA function.

• Generic read function.

• Wake-up module.

Example Description

This example demonstrates the use of GNSS 3 click by reading and displaying the GPS coordinates.

 void application_task ( void ) 
 { 
    gnss3_process( &gnss3 );
    if ( app_buf_len > ( sizeof ( ( char * ) GNSS3_RSP_GNGGA ) + GNSS3_GNGGA_ELEMENT_SIZE ) ) 
    {
        gnss3_parser_application( 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.Gnss3

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.