Intermediate
10 min

Reduce noise pollution with actionable data and insights using MCP4921 and PIC18F57Q43

Respond promptly to noise-related issues

Noise Click with Curiosity Nano with PIC18F57Q43

Published Feb 13, 2024

Click board™

Noise Click

Dev. board

Curiosity Nano with PIC18F57Q43

Compiler

NECTO Studio

MCU

PIC18F57Q43

Our noise detection solution is engineered to identify and mitigate disruptive noise, fostering quieter and more peaceful environments

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Hardware Overview

How does it work?

Noise Click is based on the MCP4921, a 12-bit DAC with an SPI interface from Microchip. This single-channel DAC has a rail-to-rail output, a fast-setting time, and 450KHz of multiplier mode. The MCP4921 on the Noise Click sets the threshold in 12-bit resolution steps from 0 up to 4096. The noise from the environment this Click board™ receives through the MM034202-11, an analog MEMS microphone from DB Unlimited. It has omnidirectional directivity, a sensitivity of around -42dB, a signal-to-noise ratio of 59dB, and works in a frequency range from 100 up to 10000Hz. This Click board™ also includes two MCP6022s, a rail-to-rail input/output 10MHz Op Amps from Microchip. The operational amplifiers feature wide bandwidth up to 10MHz, low noise, low input offset voltage, and low distortion. The first MCP6022

processes the microphone signal. Then, the amplified voltages pass through the LTC1966, a precision micropower ∆∑ RMS-to-DC converter from Analog Devices. This converter has constant bandwidth independent of the input voltage, flexible rail-to-rail inputs, and outputs and is more accurate than conventional log antilog similar RMS-to-DC converters. After processing with the LTC1966, the signal then goes into the second operational amplifier, which functions as a voltage comparator, from which the interrupt signal originates. To avoid triggering the interrupt hundreds of times per second as ambient noise oscillates near the threshold, a hysteresis circuit is also employed. For that purpose, the Noise Click comes with the MAX6106, a low-cost, micropower, low-dropout, high-output-current voltage

reference of 2.048V from Analog Devices. The Noise Click uses an SPI serial interface to communicate with the host MCU over the mikroBUS™ socket. The LTC1966 RMS-to-DC converter can be turned off with the HIGH logic state on the EN pin of the mikroBUS™ socket. No matter the logic state on the enable pin, the voltage levels can still be monitored over the AN pin. When the ambient noise reaches the set threshold, the interrupt INT pin is pulled HIGH. This Click board™ can be operated only with a 3.3V 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.

Noise Click top side image
Noise 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

Used MCU Pins

mikroBUS™ mapper

Analog Output
PA0
AN
Enable
PA7
RST
SPI Chip Select
PD4
CS
SPI Clock
PC6
SCK
NC
NC
MISO
SPI Data IN
PC4
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
PA6
INT
NC
NC
TX
NC
NC
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

Noise 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
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

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 Noise Click driver.

Key functions:

  • noise_set_cmd_reg - This function sets command register

  • noise_set_state - This function switches click ON or OFF

  • noise_read_an_pin_voltage - This function reads results of AD conversion of the AN pin and converts them to proportional voltage level

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 Noise click example
 * 
 * # Description
 * This example performs an ambient noise monitoring using the Noise click board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Device initialization.
 * 
 * ## Application Task  
 * Reads the voltage from AN pin which presents the noise level and displays it
 * on the USB UART every 5ms. If the noise is above predefined threshold
 * (25 percents of max noise, i.e. about 0.4V) an alarm message is being shown.
 * 
 * @note 
 * We recommend using the SerialPlot tool for data visualizing.
 * 
 * \author MikroE Team
 *
 */
#include "board.h"
#include "log.h"
#include "noise.h"

static noise_t noise;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;
    noise_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.
    noise_cfg_setup( &cfg );
    NOISE_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    noise_init( &noise, &cfg );

    noise_default_cfg( &noise );
}

void application_task ( void )
{
    float voltage = 0;
    if ( NOISE_OK == noise_read_an_pin_voltage ( &noise, &voltage ) )
    {
        log_printf( &logger, "%.3f\r\n", voltage );
    }
    if ( noise_check_int_pin( &noise ) )
    {
        log_printf( &logger, " Sound overlimit detected!\r\n" );
    }
    Delay_ms ( 5 );
}

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;
}


// ------------------------------------------------------------------------ END
/*!
 * \file 
 * \brief Noise click example
 * 
 * # Description
 * This example performs an ambient noise monitoring using the Noise click board.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Device initialization.
 * 
 * ## Application Task  
 * Reads the voltage from AN pin which presents the noise level and displays it
 * on the USB UART every 5ms. If the noise is above predefined threshold
 * (25 percents of max noise, i.e. about 0.4V) an alarm message is being shown.
 * 
 * @note 
 * We recommend using the SerialPlot tool for data visualizing.
 * 
 * \author MikroE Team
 *
 */
#include "board.h"
#include "log.h"
#include "noise.h"

static noise_t noise;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;
    noise_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.
    noise_cfg_setup( &cfg );
    NOISE_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    noise_init( &noise, &cfg );

    noise_default_cfg( &noise );
}

void application_task ( void )
{
    float voltage = 0;
    if ( NOISE_OK == noise_read_an_pin_voltage ( &noise, &voltage ) )
    {
        log_printf( &logger, "%.3f\r\n", voltage );
    }
    if ( noise_check_int_pin( &noise ) )
    {
        log_printf( &logger, " Sound overlimit detected!\r\n" );
    }
    Delay_ms ( 5 );
}

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;
}


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

Additional Support

Resources

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