Elevate your audio experience with MCP6H012 and STM32F407VGT6
The audiophile's dream: Analog active crossovers redefining sound purity
Published Dec 29, 2023
Click board™
Audio Xover Click
Dev. board
Clicker 4 for STM32F4
Compiler
NECTO Studio
MCU
STM32F407VGT6
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 4 for STM32F4 is a compact development board designed as a complete solution that you can use to quickly build your own gadgets with unique functionalities. Featuring an STM32F407VGT6 MCU, four mikroBUS™ sockets for Click boards™ connectivity, power management, and more, it represents a perfect solution for the rapid development of many different types of applications. At its core is an STM32F407VGT6 MCU, a powerful microcontroller by STMicroelectronics based on the high-performance
Arm® Cortex®-M4 32-bit processor core operating at up to 168 MHz frequency. It provides sufficient processing power for the most demanding tasks, allowing Clicker 4 to adapt to any specific application requirements. Besides two 1x20 pin headers, four improved mikroBUS™ sockets represent the most distinctive connectivity feature, allowing access to a huge base of Click boards™, growing on a daily basis. Each section of Clicker 4 is clearly marked, offering an intuitive and clean interface. This makes working with the
development board much simpler and, thus, faster. The usability of Clicker 4 doesn’t end with its ability to accelerate the prototyping and application development stages: it is designed as a complete solution that can be implemented directly into any project, with no additional hardware modifications required. Four mounting holes [4.2mm/0.165”] at all four corners allow simple installation by using mounting screws.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M4
MCU Memory (KB)
10
Silicon Vendor
STMicroelectronics
Pin count
100
RAM (Bytes)
100
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Clicker 4 for STM32F4 as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
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
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* \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
