Motion 2 Click

How does it work?

Motion 2 Click is using a PIR sensor that can detect changes in the amount of infrared radiation impinging upon it, which varies depending on the temperature and surface characteristics of the objects in front of the sensor. Detection performance of EKMC1607112 at ambient temperature of 25°C with temperature difference of 8°C is up to 7m and for temperature difference of 4°C it’s up to 5m.

Output from PIR sensor is feed into buffer and then photorelay alowing users to directly control with galvanic isolation from sensor and MCU electronic devices such as lights, motors, gates etc. The TLP241A photorelay is able to effectively replace traditionally used mechanical relays, bringing up the full set of inherited benefits: virtually unlimited number of cycles since there are no moving parts that would wear off, no bouncing effect on the output contacts, high resistance to mechanical shock and environmental influence, low current required for the activation, constant resistance since no carbon and rust can build up on contacts, there is no sparking or electric arc forming while operated, compact size, higher isolation voltage, and so on.

When an object, such as a person, passes in front of the background, such as a wall, the temperature at that point in the sensor’s field of view will rise from room temperature to body temperature, and then back again. The sensor converts the resulting change in the incoming infrared radiation into a change in the output voltage, and this triggers the detection. Objects of similar temperature but different surface characteristics may also have a different infrared emission pattern, and thus moving them with respect to the background may trigger the detector as well. In some cases, going back and forth towards the sensor (parallel movement to the axis Z), may not be detected.

Difficulty in sensing the heat source is that glass, acrylic or similar materials standing between the target and the sensor may not allow a correct transmission of infrared rays and also non-movement or quick movements of the heat source inside the detection area.

Specifications

Pinout diagram

This table shows how the pinout on Motion 2 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
	NC	2	RST	INT	15	INT	Interrupt
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

Detection performance and electrical characteristics

Software Support

We provide a library for the Motion 2 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

The library has a function to activate the motion sensor and functions to check Movement detection in the vicinity of the sensor.

Key functions:

• void motion2_active ( uint8_t status ) – Functions for active motion sensors
• uint8_t motion2_detect_state ( void ) – Gets detection state

Examples description

The application is composed of three sections :

• System Initialization – Initializes all necessary GPIO pins
• Application Initialization – Initializes the GPIO driver and activates the motion sensor
• Application Task – Checks if an object is detected. Prints a message about the object detection and whether the sensor has stabilized after object detection.
• Note: The sensor needs a maximum of 30s to stabilize. See the sensor technical documentation for more information.

void application_task ( )
{
    uint8_t motion_state;
    
    motion_state = motion2_detect_state( );
    
    if ( ( motion_detect_flag == 0 ) &&
         ( motion_state == MOTION2_DETECT_OBJECT ) )
    {
        mikrobus_logWrite( ">>> Object is detected...", _LOG_LINE );
        motion_detect_flag = 1;
        Delay_ms( 500 );
    }
    
    if ( ( motion_detect_flag == 1 ) && 
         ( motion_state != MOTION2_DETECT_OBJECT ) )
    {
        mikrobus_logWrite( ">>> Sensor has stabilized..", _LOG_LINE );
        mikrobus_logWrite( ">>> Ready for new detection...", _LOG_LINE );
        mikrobus_logWrite( ">>> --------------------------", _LOG_LINE );
        motion_detect_flag = 0;
    }
}

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

Other mikroE Libraries used in the example:

• UART Library

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. 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.