tRF Click

The main component on the tRF click is the LE70-868 RF module, from Telit. It operates in the 868 MHz ISM license-free frequency range. This module is composed of a digital and RF sections. The RF section is responsible for the frequency synthesis, packet handling, power amplification, and low noise reception. This module has the maximum power of 500 mW, staying compliant with the ERC recommendation 70-03, Annex 1. Digital section takes care of all the I/O management and communication interface. The embedded MCU with the Telit software stack is also a part of this section.

Specifications

Pinout diagram

This table shows how the pinout on tRF click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Standby/Wakeup	STB	1	AN	PWM	16	STS	UART TX Status
Reset	RST	2	RST	INT	15	ACK	Acknowledgement
	NC	3	CS	RX	14	TXD	UART Transmit
	NC	4	SCK	TX	13	RXD	UART Receive
	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

Software support

We provide a library for the tRF click on our LibStock page, as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Library Description

Initializes and defines UART bus driver, and defines driver’s functions for comunication (reading and writing) between tRF clicks.

Key functions:

• void trf_writeByte(uint8_t input) - Function writes (sends) one byte in UART rx buffer

• uint8_t trf_readByte() - Function reads (receives) one byte from UART rx buffer

• uint8_t trf_byteReady() - Function checks state of rx buffer (is new data placed in)

• void trf_reset() - Function resets click and sets back in normal operating mode

Example description

The application is composed of three sections:

• System Initialization – Intializes UART module
• Application Initialization – Driver intialization
• Application Task – (code snippet) – Checks if new data byte have received in rx buffer (ready for reading), and if ready than reads one byte from rx buffer. In second case aplication task writes message data via UART.

void applicationTask()
{
 char tmp;
 uint8_t rdyFlag;

// RECEIVER - UART polling 

 rdyFlag = trf_byteReady();

 if (1 == rdyFlag)
 {
 tmp = trf_readByte();
 mikrobus_logWrite( &tmp, _LOG_BYTE );
 }

// TRANSMITER - TX each 2 sec

 /*for (tmp = 0; tmp < 9; tmp++)
 {
 trf_writeByte( MESSAGE_DATA[tmp] );
 mikrobus_logWrite( "MESSAGE SENT", _LOG_LINE );
 Delay_100ms();
 }
 Delay_ms(2000);*/
}

${EXAMPLE_ADDITIONAL_FUNCTIONS}

The full application code, and ready to use projects can be found on our LibStock page.

Other mikroE Libraries used in the example:

• Conversions
• UART

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.