Audio Xover Click

How does it work

Audio Xover Click is using three Butterworth filters (one for each speaker) with possibility of changing cutoff frequency between 120Hz, 90Hz and 70Hz. Butterworth filters are called maximally flat filters because, for a given order, they have the sharpest roll-off possible without inducing peaking in the Bode plot. The two-pole filter with a damping ratio of 0.707 is the second-order Butterworth filter.

Audio crossovers are a type of electronic filter circuitry used in a range of audio applications, to split up an audio signal into two or more frequency ranges, so that the signals can be sent to drivers that are designed for different frequency ranges.

Active crossovers are distinguished from passive crossovers in that whereas passive crossovers split up an amplified signal coming from one power amplifier so that it can be sent to two or more drivers (e.g., a woofer and a very low frequency subwoofer, or a woofer and a tweeter), an active crossover splits up audio signal prior to amplification, so that it can be sent to two or more power amplifiers, each of which is connected to a separate driver type.

Active crossovers as Audio Xover Click don’t care how powerful your amplifiers are because they process the signal before it enters the amplifier. Active crossovers are also not very sensitive to temperature variations, so they can be very accurate, all the time. If one of the amplifiers channels in an active crossover system clips, the distortion only affects that single channel.

Specifications

Pinout diagram

This table shows how the pinout on Audio Xover 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	NC
Shutdown	SDN	3	CS	RX	14	NC
	NC	4	SCK	TX	13	NC
	NC	5	MISO	SCL	12	NC
	NC	6	MOSI	SDA	11	NC
	NC	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

Software Support

We provide a library for the Audio Xover 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

Library contains function for enable and disable module.

Key functions:

• void audioxover_set_mode( uint8_t state ) – This function set CS pin on 1 ( ENABLE ) and 0 ( DISABLE )

Examples description

The application is composed of three sections :

• System Initialization – Initializes all necessary GPIO pins
• Application Initialization – Initializes driver init
• Application Task – Enable and disable module every one seconds.

void application_task ( )
{
    mikrobus_logWrite( "***ENABLE****", _LOG_LINE );
    audioxover_set_mode( AUDIOXOVER_ENABLE );
    Delay_ms( 3000 );
    mikrobus_logWrite( "***DISABLE****", _LOG_LINE );
    audioxover_set_mode( AUDIOXOVER_DISABLE );
    Delay_ms( 3000 );
}

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

Other mikroE Libraries used in the example:

• LOG(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.