Bid farewell to frustrating volume fluctuations thanks to NJU72341 and STM32L073RZ combo solution
Experience audio nirvana: Your volume, your way
Published Feb 26, 2024
Click board™
Volume 2 Click
Dev. board
Nucleo-64 with STM32L073RZ MCU
Compiler
NECTO Studio
MCU
STM32L073RZ
Experience a higher level of audio quality and precision with our volume control device, which enhances clarity and fidelity for a more immersive listening experience
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Hardware Overview
How does it work?
Volume 2 Click is based on the NJU72341, a 2-channel I2C configurable electronic volume IC with an external mute control from JRC. The NJU72341 operates as an audio signal processor with many characteristics useful in an audio application, such as low noise typical of 2.0µVrms and low distortion of 0.002%. It controls two independent audio channels with a vast volume control range from 0 to 95dB with 1dB step offering zero-cross detection to protect against pop noise. This Click board™ is suitable for stereo and multi-channel audio systems. The NJU72341 has to receive a specific supply voltage to operate
appropriately, in this case, 12V. Unlike the Volume Click, which has a symmetrical power supply, we have only one positive power supply in this case. Bringing just a positive power supply, the noise generated by that power supply will transmit to the output, representing a side effect. For this purpose, Volume 2 Click employs a boost converter unit that combines MIC5235 and MIC2606, both from Microchip. MIC5235 provides 13V out of 5V from the mikroBUS™ power rail, which then the MIC2606, with a feature of massive noise suppression, lowers it to 12V and then supplies NJU72341, reducing the noise generated
at its output. Volume 2 Click communicates with MCU using a standard I2C 2-Wire interface, with a clock frequency up to 100kHz in the Standard and 400kHz in the Fast Mode. Also, the user can have external mute control configurable through the PWM pin of the mikroBUS™ socket labeled as MTE. 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
Nucleo-64 with STM32L073RZ MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
192
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
20480
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
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 Nucleo-64 with STM32L073RZ MCU 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 Volume 2 Click driver.
Key functions:
volume2_update_vol_data- This function updates the volume by using direct defined structure optionsvolume2_device_mute- This function is used to set mute on or off by controlling the mte pinvolume2_generic_write- This function writes a desired number of data bytes starting from the selected register by using I2C serial interface
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 main.c
* @brief Volume2 Click example
*
* # Description
* This example shows how Volume 2 click board can be used
* for controlling the audio channels. Thanks to this, a
* simple audio effect is created by switching volume from
* right to left and vice versa.
*
* The demo application is composed of two sections :
*
* ## Application Init
* UART LOG and I2C drivers are initialized, following the
* default configuration. By default, both channels are set
* to 9 dB gain with zero cross detection enabled.
*
* ## Application Task
* The task performs and effect of switching the volume
* from right to left channel and vice versa. Like playing
* ping-pong with the sound.
*
* @author Stefan Nikolic
*
*/
#include "board.h"
#include "log.h"
#include "volume2.h"
static volume2_t volume2;
static log_t logger;
static volume2_vol_data_t volume_upd_data;
static uint8_t rising_vol;
static uint8_t max_atten = 60;
void application_init ( void ) {
log_cfg_t log_cfg; /**< Logger config object. */
volume2_cfg_t volume2_cfg; /**< Click config object. */
/**
* 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.
volume2_cfg_setup( &volume2_cfg );
VOLUME2_MAP_MIKROBUS( volume2_cfg, MIKROBUS_1 );
err_t init_flag = volume2_init( &volume2, &volume2_cfg );
if ( init_flag == I2C_MASTER_ERROR ) {
log_error( &logger, " Application Init Error. " );
log_info( &logger, " Please, run program again... " );
for ( ; ; );
}
volume2_default_cfg( &volume2 );
Delay_ms( 100 );
log_info( &logger, " Application Task " );
}
void application_task ( void ) {
for ( rising_vol = 0 ; rising_vol < max_atten ; rising_vol++ ) {
volume_upd_data.attenuation_ch1 = rising_vol;
volume_upd_data.attenuation_ch2 = max_atten - rising_vol;
volume2_update_vol_data( &volume2, volume_upd_data );
Delay_ms( 50 );
}
Delay_ms( 1000 );
for ( rising_vol = 0 ; rising_vol < max_atten ; rising_vol++ ) {
volume_upd_data.attenuation_ch1 = max_atten - rising_vol;
volume_upd_data.attenuation_ch2 = rising_vol;
volume2_update_vol_data( &volume2, volume_upd_data );
Delay_ms( 50 );
}
Delay_ms( 1000 );
}
void main ( void ) {
application_init( );
for ( ; ; ) {
application_task( );
}
}
// ------------------------------------------------------------------------ END
