Delve into the realm of high-fidelity audio with our analog active crossover solution, designed to enhance clarity and precision in two-way loudspeakers
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Hardware Overview
How does it work?
Audio Xover Click is based on the MCP6H012, an operational amplifier with rail-to-rail output operation from Microchip. It uses 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. This Click board™ can be operated only with a 5V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.
Features overview
Development board
Clicker 2 for Kinetis is a compact starter development board that brings the flexibility of add-on Click boards™ to your favorite microcontroller, making it a perfect starter kit for implementing your ideas. It comes with an onboard 32-bit ARM Cortex-M4F microcontroller, the MK64FN1M0VDC12 from NXP Semiconductors, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, LED indicators, buttons, a JTAG programmer connector, and two 26-pin headers for interfacing with external electronics. Its compact design with clear and easily recognizable silkscreen markings allows you to build gadgets with unique functionalities and
features quickly. Each part of the Clicker 2 for Kinetis development kit contains the components necessary for the most efficient operation of the same board. In addition to the possibility of choosing the Clicker 2 for Kinetis programming method, using a USB HID mikroBootloader or an external mikroProg connector for Kinetis programmer, the Clicker 2 board also includes a clean and regulated power supply module for the development kit. It provides two ways of board-powering; through the USB Micro-B cable, where onboard voltage regulators provide the appropriate voltage levels to each component on the board, or
using a Li-Polymer battery via an onboard battery connector. All communication methods that mikroBUS™ itself supports are on this board, including the well-established mikroBUS™ socket, reset button, and several user-configurable buttons and LED indicators. Clicker 2 for Kinetis is an integral part of the Mikroe ecosystem, allowing you to create a new application in minutes. Natively supported by Mikroe software tools, it covers many aspects of prototyping thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
1024
Silicon Vendor
NXP
Pin count
121
RAM (Bytes)
262144
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Track your results in real time
Application Output
After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.
After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.
Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.
Software Support
Library Description
This library contains API for Audio Xover Click driver.
Key functions:
audioxover_power_on
- Device power on function.audioxover_shut_down
- Device shut down function
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* \file
* \brief Audio Xover Click example
*
* # Description
* This example demonstrates the use of the Audio Xover click board.
* The click is an analog active crossover solution for two-way loudspeakers.
* The primary purpose of the crossover circuit in a loudspeaker is to split
* an incoming audio signal into frequency bands that are passed to
* the speaker best suited.
*
* The demo application is composed of two sections :
*
* ## Application Init
* This function initializes the driver and makes an initial log.
*
* ## Application Task
* This function enables and disables the click board every 10 seconds,
* and logs an appropriate message on the USB UART.
*
* @note
* The hardware revision v100 of the click board works only with MCUs that operates
* at 5V operating voltage level.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "audioxover.h"
// ------------------------------------------------------------------ VARIABLES
static audioxover_t audioxover;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
audioxover_cfg_t cfg;
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, "---- Application Init ----" );
// Click initialization.
audioxover_cfg_setup( &cfg );
AUDIOXOVER_MAP_MIKROBUS( cfg, MIKROBUS_1 );
audioxover_init( &audioxover, &cfg );
}
void application_task ( void )
{
log_printf( &logger, " * Switch: ON *\r\n" );
audioxover_power_on ( &audioxover );
Delay_ms( 10000 );
log_printf( &logger, " * Switch: OFF *\r\n" );
audioxover_shut_down ( &audioxover );
Delay_ms( 10000 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END