Microwave 4 Click

How does it work?

Microwave 4 Click is based on the PD-V12, a miniature high-frequency microwave transceiver from Ningbo Pdlux Electronic Technology. This motion sensor is a K-band Bi-Static Doppler transceiver module. It is housed in a metal can and features a built-in resonator oscillator (CRO), providing a stable operation as it improves its front signal-receiving ability and reduces its flank blind area. The Microwave 4 Click detects the frequency shift between a transmitted and a received signal reflected from a moving object within the field of view of the transceiver.

The radiated power (EIRP) emissions of <3mW at maximum meet the FCC and CE rules. The noise voltages at the output port inside an anechoic chamber are measured from 10Hz to 100Hz. The received signal strength (RSS) is measured at the total 1 Ways path loss of 70dB. The module uses two antennas (for RX and TX) with a maximum gain of 0dBi and is designed to be installed in such a way that allows it to operate at closer than 20cm to users or nearby persons.

The produced low-level output is amplified over the MCP6022, a rail-to-rail input/output 10MHz operational amplifier from Microchip. The amplified output goes to the ADC SEL jumper, which allows you to read the data over an analog pin of the mikroBUS™ socket or the MCP3221, a low-power 12-bit A/D converter from Microchip. The jumper is set to an analog pin by default. If the option is the ADC, you can count up to 22.3ksps in I2C fast mode.

As mentioned, the Microwave 4 Click uses an analog AN pin of the mikroBUS™ socket or a standard 2-Wire I2C interface of the MCP3221 to communicate with the host MCU. The I2C of the ADC supports standard (100KHz) and fast (400KHz) modes. Depending on the ADC of the host MCU, the onboard 12-bit ADC could be a better choice.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL 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 Microwave 4 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Analog Input	AN	1	AN	PWM	16	NC
	NC	2	RST	INT	15	NC
	NC	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	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	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Microwave 4 Click electrical specifications

Software Support

We provide a library for the Microwave 4 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 Microwave 4 Click driver.

Key functions

• microwave4_read_raw_adc Microwave 4 read raw ADC value function.

• microwave4_read_voltage Microwave 4 read voltage level function.

• microwave4_set_vref Microwave 4 set vref function.

Example Description

This example demonstrates the use of the Microwave 4 Click board™ by reading and displaying the results of AD conversion and motion detection.

 void application_task ( void )  
 { 
     if ( MICROWAVE4_OK == microwave4_read_voltage( &microwave4, &voltage ) ) 
     { 
         if ( ( ( voltage + MICROWAVE4_THRESHOLD ) < reference ) ||  
              ( ( voltage - MICROWAVE4_THRESHOLD ) > reference ) ) 
         { 
             if ( MICROWAVE4_FLAG_SET == flag ) 
             { 
                 log_printf( &logger, " Motion detected!rn" ); 
                 log_printf( &logger, " Detector AN Voltage : %.3f[V]rn", voltage ); 
                 log_printf( &logger, "----------------------------------rn" ); 
                 flag = MICROWAVE4_FLAG_CLEAR; 
                 Delay_ms( 100 ); 
             } 
         } 
         else 
         { 
             flag = MICROWAVE4_FLAG_SET; 
         } 
     } 
 }

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.Microwave4

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.