Record and play back audio messages using the ISD1616B and STM32F031K6
Single-message voice record and playback solution
Published Oct 14, 2024
Click board™
Rec&Play 2 Click
Dev. board
Nucleo 32 with STM32F031K6 MCU
Compiler
NECTO Studio
MCU
STM32F031K6
Record and play high-quality audio with ease, perfect for alarms, voice prompts, and automated announcements
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Hardware Overview
How does it work?
Rec&Play 2 Click is based on the ISD1616B, a single-message voice record and playback IC from Nuvoton designed for voice recording and playback applications. This highly integrated solution includes all the necessary components to deliver superior audio recording and playback functionality. It features an on-chip oscillator, a microphone preamplifier with Automatic Gain Control (AGC), and an omnidirectional electret microphone (CMC-2242PBL-A) for optimal audio capture. The built-in anti-aliasing filter ensures smooth, high-quality recording, while the Multi-Level Storage (MLS) array provides efficient data handling. Voice and audio data are stored directly in the onboard Flash memory without digital compression, ensuring high-quality playback. A smoothing filter and Pulse Width Modulation (PWM) Class D speaker driver control the integrated speaker (AS01508AO-SC-R), delivering clear and precise audio output. With zero-power message storage, recordings remain intact even without a power supply. Rec&Play 2 Click is ideal for various audio playback
applications, including alarms, voice prompts, and automated announcements, where clear and reliable audio is essential. The ISD1616B can be managed both manually and digitally. Manual control is available through dedicated buttons: REC, E, and L. The REC button enables voice recording, which continues as long as the button remains pressed. The E and L buttons handle playback, offering two distinct modes: the E button is used for edge-trigger playback, while the L button is for level-trigger playback. In edge-trigger playback mode, pressing the E button for longer than the specified debounce time initiates playback from the beginning of the memory, continuing until an End-Of-Message (EOM) marker is reached, after which the device automatically enters standby mode. In level-trigger playback mode, pressing the L button starts playback from the beginning of the memory, and it runs until an EOM marker is reached, then powers down automatically. These same functions can also be controlled digitally via the REC, PE, and PL pins on the mikroBUS™
socket. The message duration is user-selectable, ranging from 10 to 24 seconds, depending on the configuration of the onboard REC/Play Duration switches. In addition to these switches, the board features a visual guide to indicate the switch positions and corresponding recording/playback durations of 10, 16, 20, or 24 seconds. It also includes an orange status LED indicator, which stays illuminated during recording and blinks several times per second during playback, providing visual feedback on the operation status. 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. It also supports battery power, enabling standalone applications without needing an external power supply. Additionally, 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.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
32
Silicon Vendor
STMicroelectronics
Pin count
32
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
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 32 with STM32F031K6 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 Rec&Play 2 Click driver.
Key functions:
recnplay2_set_pl_pin- This function sets the PL pin on the selected level of Rec&Play 2 Click.recnplay2_record_sound- This function is used to record sound with Rec&Play 2 Click.recnplay2_play_sound- This function is used to play recorded sounds with Rec&Play 2 Click.
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 Rec N Play 2 Click Example.
*
* # Description
* This example demonstrates the use of Rec N Play 2 Click board by
* recording and then playing recorded sound.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver, performs the click default configuration.
*
* ## Application Task
* Recording sound for 5 seconds, then playing it back.
*
* @author Stefan Ilic
*
*/
#include "board.h"
#include "log.h"
#include "recnplay2.h"
static recnplay2_t recnplay2; /**< Rec N Play 2 Click driver object. */
static log_t logger; /**< Logger object. */
#define RECORDING_LEN 5000
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
recnplay2_cfg_t recnplay2_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.
recnplay2_cfg_setup( &recnplay2_cfg );
RECNPLAY2_MAP_MIKROBUS( recnplay2_cfg, MIKROBUS_1 );
if ( DIGITAL_OUT_UNSUPPORTED_PIN == recnplay2_init( &recnplay2, &recnplay2_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
recnplay2_default_cfg ( &recnplay2 );
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
log_printf( &logger, " Recording... \r\n" );
recnplay2_record_sound( &recnplay2, RECORDING_LEN );
Delay_ms( 1000 );
log_printf( &logger, " Playing... \r\n" );
recnplay2_play_sound( &recnplay2, RECORDING_LEN );
Delay_ms( 1000 );
}
int main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
