Add audible alerts or feedback to your projects with CPT-7502-65-SMT-TR and STM32F031K6

Piezoelectric buzzer transducer for generating sound signals in various electronic applications

Buzzer Click with Nucleo 32 with STM32F031K6 MCU

Published Oct 01, 2024

Click board™

Buzzer Click

Dev. board

Nucleo 32 with STM32F031K6 MCU

Compiler

NECTO Studio

MCU

STM32F031K6

Generate audible alerts for security systems or sound signals for notifications or reminders in various projects

Hardware Overview

How does it work?

Buzzer Click is based on the CPT-7502-65-SMT-TR, a piezoelectric buzzer transducer from CUI Devices designed for efficient and reliable sound output in a surface-mount form factor. The buzzer has a compact square shape with dimensions of 7.5x7.5x2mm and offers a sound pressure level of 65dB, ensuring clear and noticeable sound in various applications. It is externally driven, meaning it requires an external circuit for activation, which is placed on this board. It consumes a low current of only 1mA, making it suitable for battery-powered devices. This Click board™ is designed in a unique format supporting the newly introduced MIKROE feature called "Click

Snap." Unlike the standardized version of Click boards, this feature allows the main sensor area to become movable by breaking the PCB, opening up many new possibilities for implementation. Thanks to the Snap feature, the CPT-7502-65-SMT-TR can operate autonomously by accessing its signals directly on the pins marked 1-8. Additionally, the Snap part includes a specified and fixed screw hole position, enabling users to secure the Snap board in their desired location. This Click board™ uses an N-channel MOSFET to control the buzzer via a PWM signal, allowing for precise modulation of the sound's frequency and intensity. When the PWM signal is applied, the MOSFET enables the flow of

current through the piezoelectric buzzer, activating it and producing sound. This setup provides flexibility in controlling the buzzer's output, making it a versatile solution for sound signaling in various electronic projects. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.

Features overview

Development board

Nucleo 32 with STM32F031K6 MCU board provides an affordable and flexible platform for experimenting with STM32 microcontrollers in 32-pin packages. Featuring Arduino™ Nano connectivity, it allows easy expansion with specialized shields, while being mbed-enabled for seamless integration with online resources. The

board includes an on-board ST-LINK/V2-1 debugger/programmer, supporting USB reenumeration with three interfaces: Virtual Com port, mass storage, and debug port. It offers a flexible power supply through either USB VBUS or an external source. Additionally, it includes three LEDs (LD1 for USB communication, LD2 for power,

and LD3 as a user LED) and a reset push button. The STM32 Nucleo-32 board is supported by various Integrated Development Environments (IDEs) such as IAR™, Keil®, and GCC-based IDEs like AC6 SW4STM32, making it a versatile tool for developers.

Nucleo 32 with STM32F031K6 MCU double side image

Microcontroller Overview

MCU Card / MCU

Architecture

ARM Cortex-M0

MCU Memory (KB)

Silicon Vendor

STMicroelectronics

Pin count

RAM (Bytes)

4096

You complete me!

Accessories

Click Shield for Nucleo-32 is the perfect way to expand your development board's functionalities with STM32 Nucleo-32 pinout. The Click Shield for Nucleo-32 provides two mikroBUS™ sockets to add any functionality from our ever-growing range of Click boards™. We are fully stocked with everything, from sensors and WiFi transceivers to motor control and audio amplifiers. The Click Shield for Nucleo-32 is compatible with the STM32 Nucleo-32 board, providing an affordable and flexible way for users to try out new ideas and quickly create prototypes with any STM32 microcontrollers, choosing from the various combinations of performance, power consumption, and features. The STM32 Nucleo-32 boards do not require any separate probe as they integrate the ST-LINK/V2-1 debugger/programmer and come with the STM32 comprehensive software HAL library and various packaged software examples. This development platform provides users with an effortless and common way to combine the STM32 Nucleo-32 footprint compatible board with their favorite Click boards™ in their upcoming projects.

Used MCU Pins

mikroBUS™ mapper

RST

ID COMM

PA4

SCK

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM Signal

PA8

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Click Shield for Nucleo-144 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Nucleo 32 with STM32F031K6 MCU as your development board.

Nucleo 144 with STM32L4A6ZG MCU front image hardware assembly

2x4 RGB Click front image hardware assembly

Nucleo-32 with STM32 MCU MB 1 - upright/background hardware assembly

Clicker 4 for STM32F4 HA MCU Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step hardware assembly

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 Buzzer Click driver.

Key functions:

buzzer_play_sound - This function plays sound on the buzzer.

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 Buzzer Click example
 *
 * # Description
 * This example demonstrates the use of Buzzer click board by playing
 * the Imperial March melody on the buzzer.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes the driver and logger.
 * 
 * ## Application Task  
 * Plays the Imperial March melody. Also logs an appropriate message on the USB UART.
 * 
 * @note
 * The minimal PWM Clock frequency required for this example is the frequency of tone C6 - 1047 Hz. 
 * So, in order to run this example and play all tones correctly, the user will need to decrease 
 * the MCU's main clock frequency in MCU Settings for the certain architectures
 * in order to get the required PWM clock frequency.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "buzzer.h"

static buzzer_t buzzer;
static log_t logger;

/**
 * @brief Buzzer imperial march function.
 * @details This function plays the Imperial March melody on the buzzer
 * at the selected volume level.
 * @param[in] volume : Buzz sound level. ( min = 1, max = 100 )
 * @return None.
 * @note None.
 */
static void buzzer_imperial_march ( uint8_t volume );

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    buzzer_cfg_t buzzer_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.
    buzzer_cfg_setup( &buzzer_cfg );
    BUZZER_MAP_MIKROBUS( buzzer_cfg, MIKROBUS_1 );
    if ( PWM_ERROR == buzzer_init( &buzzer, &buzzer_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    log_printf( &logger, " Playing the Imperial March melody...\r\n" );
    buzzer_imperial_march( BUZZER_VOLUME_MAX ); 
    Delay_ms ( 1000 );
    Delay_ms ( 1000 );
}

int main ( void ) 
{
    /* Do not remove this line or clock might not be set correctly. */
    #ifdef PREINIT_SUPPORTED
    preinit();
    #endif
    
    application_init( );
    
    for ( ; ; ) 
    {
        application_task( );
    }

    return 0;
}

static void buzzer_imperial_march ( uint8_t volume )
{
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_HALF );
    Delay_ms ( BUZZER_NOTE_LEN_HALF );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_E7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_E7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_E7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F7, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Ab6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_HALF );
    Delay_ms ( BUZZER_NOTE_LEN_HALF );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Ab7, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_G7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Gb7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_E7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F7, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Bb6, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Eb7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_D7, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Db7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_B6, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Ab6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_E7, volume, BUZZER_NOTE_LEN_HALF );
    Delay_ms ( BUZZER_NOTE_LEN_HALF );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Ab7, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_G7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Gb7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_E7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F7, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Bb6, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Eb7, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_D7, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Db7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_B6, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Ab6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    
    buzzer_play_sound( &buzzer, BUZZER_NOTE_A6, volume, BUZZER_NOTE_LEN_QUARTER );
    Delay_ms ( BUZZER_NOTE_LEN_QUARTER );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_F6, volume, BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_EIGHTH + BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_C7, volume, BUZZER_NOTE_LEN_SIXTEENTH );
    Delay_ms ( BUZZER_NOTE_LEN_SIXTEENTH );
    buzzer_play_sound( &buzzer, BUZZER_NOTE_Ab6, volume, BUZZER_NOTE_LEN_HALF );
    Delay_ms ( BUZZER_NOTE_LEN_HALF );
}

// ------------------------------------------------------------------------ END