GSM2 Click

How does it work?

GPS 2 Click is based on the M95, a quad-band GSM/GPRS module from Quectel. The module supports quad-band GSM/GPRS, allowing it to be used worldwide. It covers frequencies of 850/900 MHz with up to 2W and frequencies of 1800/1900 MHz with up to 1W transmitting power. The M95 module is also compliant with the eCall EU Directive. The module is the Click board’s main component, consisting of several internal blocks or sections, such as the antenna switching section, RF transceiver section, memory, power management, and most importantly – the cellular baseband processor.

The M95 module has to be powered by 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 M95 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 M95 are internally supplied by 2.8V, so it is necessary to condition the communication bus lines that connect the host MCU with the module. M95 outputs 2.8V output from its internal LDO, providing a needed reference voltage for one side of the TXB0106, a 6-bit bidirectional level shifting and voltage translator with automatic direction sensing from Texas Instruments.

The M95 offers extensive audio features, including half rate, full rate, enhanced full rate and adaptive multi-rate voice codecs, superior echo cancellation, and noise reduction. The headset can be connected via the 4-pole 3.5mm audio jack. The Micro SIM card holder on the back of the Click board™ is used to install a microSIM card. This device cannot be used without a valid SIM card, which allows connection to the cellular network. Both 1.8V and 3V SIM card types are supported.

GSM 2 Click uses a standard 2-Wire UART interface to communicate with the host MCU, with commonly used UART RX and TX pins, and supporting data rates from 300bps up to 115200bps with automatic baud rate detection. In addition, the UART RTS and CTS hardware flow control pins are also available. Besides the library we provide, you can also use the AT commands. The RI pin serves as a ringing indicator. There is also a PWK pin for powering the module and the STA pin, which indicates the device status. This status is also represented over the STA LED. The other LED is a NET LED, which indicates the network status.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the I/O Level jumper. 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 GSM2 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Device Status Output	STA	1	AN	PWM	16	RI	UART RI
Power Key	PWK	2	RST	INT	15	CTS	UART CTS
UART RTS	RTS	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	3V3	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

GSM2 Click electrical specifications

Software Support

We provide a library for the GSM 2 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 GSM 2 Click driver.

Key functions

• Enables or disables module power.

• Reset module.

• Command function.

Example Description

This example reads and processes data from GSM 2 clicks.

 void application_task ( void ) 
 { 
   gsm2_process(  ); 
 }

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.Gsm2

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.