Intermediate
30 min

Achieve premium audio quality with LM4811 and PIC18F57Q43

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Headphone AMP Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

Headphone AMP Click

Dev.Board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

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Hardware Overview

How does it work?

Headphone AMP Click is based on the LM4811, a stereo, analog input headphone amplifier with digital volume control from Texas Instruments. This headphone amplifier is designed to provide high-quality output power using few external components and does not require bootstrap capacitors or snubber networks for stability improvement. The maximum power delivered by the LM4811 headphone amplifier is 105mW per channel into 16Ω and 70mW with 16Ω load impedance. Other prominent features of the ML4811 also include digital volume control, "Click and Pop" suppression circuitry, and a low shutdown current of 0.3μA. This Click board™ communicates with MCU using several GPIO pins.

The signals from the CLK and U/D pins routed to the PWM and INT pins of the mikroBUS™ socket control the LM4811's gain. The gain will increase or decrease by a 3dB step depending on the logic voltage level applied to the U/D pin at each rising edge of the CLK signal. A logic high voltage level applied to the U/D pin causes the gain to increase by 3dB at each rising edge of the CLK signal and vice versa. The amplifier's gain is set to a default value of 0dB upon the devices' Power-On features. Sixteen discrete gain settings range from +12dB maximum to −33dB minimum. The unity-gain stable LM4811 also features an externally controlled, active-high, micro-power consumption Shutdown mode, available on the RST pin of the

mikroBUS™ socket, to reduce power consumption while not in use. However, when coming out of Shutdown mode, the LM4811 will revert to its previous gain setting. Alongside all these features, the LM4811 also has an internal thermal shutdown protection mechanism. 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.

Headphone AMP Click top side image
Headphone AMP Click bottom side image

Features overview

Development board

PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive

mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI

GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.

PIC18F57Q43 Curiosity Nano double side image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

48

RAM (Bytes)

8196

You complete me!

Accessories

Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.

Curiosity Nano Base for Click boards accessories 1 image

These standard small stereo earphones offer a high-quality listening experience with their top-notch stereo cable and connector. Designed for universal compatibility, they effortlessly connect to all MIKROE mikromedia and multimedia boards, making them an ideal choice for your electronic projects. With a rated power of 100mW, the earphones provide crisp audio across a broad frequency range from 20Hz to 20kHz. They boast a sensitivity of 100 ± 5dB and an impedance of 32Ω ± 15%, ensuring optimal sound quality. The Φ15mm speaker delivers clear and immersive audio. Cost-effective and versatile, these earphones are perfect for testing your prototype devices, offering an affordable and reliable audio solution to complement your projects.

Headphone AMP Click accessories image

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
Shutdown
PA7
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Clock Signal
PB0
PWM
Gain Control
PA6
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Headphone AMP Click Schematic schematic

Step by step

Project assembly

Curiosity Nano Base for Click boards front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.

Curiosity Nano Base for Click boards front image hardware assembly
Charger 27 Click front image hardware assembly
PIC18F47Q10 Curiosity Nano front image hardware assembly
Prog-cut hardware assembly
Charger 27 Click complete accessories setup image hardware assembly
Curiosity Nano with PICXXX Access MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
Necto image step 5 hardware assembly
Necto image step 6 hardware assembly
PIC18F57Q43 Curiosity MCU Step hardware assembly
Necto No Display image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Debug Image Necto Step hardware 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.

Application Output Step 1

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™.

Application Output Step 3

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.

Application Output Step 4

Software Support

Library Description

This library contains API for Headphone AMP Click driver.

Key functions:

  • headphoneamp_set_sound_volume - Headphone AMP set sound volume function

  • headphoneamp_volume_up - Headphone AMP set sound volume up function

  • headphoneamp_volume_down - Headphone AMP set sound volume 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 main.c
 * @brief Headphone AMP Click Example.
 *
 * # Description
 * This library contains API for the Headphone AMP click driver.
 * This demo application shows use of a Headphone AMP click board™.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of GPIO module and log UART.
 * After driver initialization the app set default settings, 
 * performs power-up sequence, sets a the sound volume of -12 dB.
 *
 * ## Application Task
 * This is an example that shows the use of Headphone AMP click board™.
 * The app performs circles the volume from -12 dB to 3 dB back and forth,
 * increase/decrement by 3dB.
 * Results are being sent to the Usart Terminal where you can track their changes.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "headphoneamp.h"

static headphoneamp_t headphoneamp;   /**< Headphone AMP Click driver object. */
static log_t logger;                  /**< Logger object. */

void application_init ( void ) 
{
    log_cfg_t log_cfg;                    /**< Logger config object. */
    headphoneamp_cfg_t headphoneamp_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.

    headphoneamp_cfg_setup( &headphoneamp_cfg );
    HEADPHONEAMP_MAP_MIKROBUS( headphoneamp_cfg, MIKROBUS_1 );
    if ( headphoneamp_init( &headphoneamp, &headphoneamp_cfg ) == DIGITAL_OUT_UNSUPPORTED_PIN ) 
    {
        log_error( &logger, " Application Init Error. " );
        log_info( &logger, " Please, run program again... " );

        for ( ; ; );
    }
    headphoneamp_default_cfg ( &headphoneamp );
    log_info( &logger, " Application Task " );
    Delay_ms( 100 );
    
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "    Performs Power-up\r\n" );
    headphoneamp_power_up( &headphoneamp );
    Delay_ms( 100 );
    
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "  Set volume gain -12dB\r\n", HEADPHONEAMP_SOUND_VOLUME_NEG_12_dB );
    headphoneamp_set_sound_volume( &headphoneamp, HEADPHONEAMP_SOUND_VOLUME_NEG_12_dB ); 
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms( 5000 );
}

void application_task ( void ) 
{
    for ( uint8_t n_cnt = 0; n_cnt < 5; n_cnt++ ) {
        log_printf( &logger, "    Turning volume up\r\n" );
        headphoneamp_volume_up ( &headphoneamp ); 
        Delay_ms( 2000 );    
    }
    
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms( 5000 );
    
    for ( uint8_t n_cnt = 0; n_cnt < 5; n_cnt++ ) {
        log_printf( &logger, "   Turning volume down\r\n" );
        headphoneamp_volume_down ( &headphoneamp ); 
        Delay_ms( 2000 );    
    }
       
    log_printf( &logger, "-------------------------\r\n" );
    Delay_ms( 5000 );
}

void main ( void ) 
{
    application_init( );

    for ( ; ; ) 
    {
        application_task( );
    }
}

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

Additional Support

Resources