RF Meter 3 Click

How does it work?

RF Meter 3 Click as its foundation uses the LT5581, RMS power detector with a 40dB dynamic range from Analog Devices. Users can use an RF power meter like this one to measure and document pulsed RF signals, noise-like signals, and pseudorandom signals. The RMS detector uses a proprietary technique to measure the RF power from 2GHz up to 2.6GHz accurately. Moreover, the LT5581 offers exceptional accuracy over its operating temperature range of -40°C to 85°C.

Its RMS measurement capability provides accurate RF power readings to within ±0.2dB regardless of waveforms with high crest-factor modulated content, multi-carrier or multitone. The LT5581 combines a proprietary high-speed power measurement subsystem with an internal 150kHz low pass averaging filter and an output voltage buffer in a completely integrated solution to achieve an accurate average power measurement of the high crest factor modulated RF signals. The resulting output voltage is directly proportional to the average RF input power in dBm.

This Click board™ uses two mikroBUS™ pins for direct control. The Enable pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes power consumption and is used for power ON/OFF purposes (Shutdown feature). When its Enable input pin is pulled low, the LT5581 draws a typical shutdown current of 0.2uA and a maximum of 6uA. As mentioned before, the resulting output voltage of the LT5581 is sent directly to an analog pin of the mikroBUS™ socket labeled as AN for MCU to read further and analyze RF signal data.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. However, the 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 RF Meter 3 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog Signal	AN	1	AN	PWM	16	NC
	NC	2	RST	INT	15	NC
Enable	EN	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

RF Meter 3 Click electrical specifications

Software Support

We provide a library for the RF Meter 3 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

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

Library Description

This library contains API for RF Meter 3 Click driver.

Key functions

• rfmeter3_enable_device This function enables device by setting EN pin to HIGH logic level.

• rfmeter3_disable_device This function disables device by setting EN pin to LOW logic level.

• rfmeter3_get_rf_input_power This function reads the voltage from AN pin and converts it to RF input power in dBm.

Example Description

This example demonstrates the use of RF Meter 3 Click board™.

 void application_task ( void ) 
 { 
     float rfmeter3_rf_input_power = 0; 

     if ( RFMETER3_ERROR != rfmeter3_get_rf_input_power ( &rfmeter3, &rfmeter3_rf_input_power ) )  
     { 
         log_printf( &logger, " RF Input Power: %.2f dBmrn", rfmeter3_rf_input_power ); 
         Delay_ms( 100 ); 
     } 
 }

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.RFMeter3

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 MikroElektronika compilers.

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.