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Gain voltage insights with LM2903 and PIC18LF47K42 like never before

Compare, control, conquer!

Comparator Click with EasyPIC v8

Published Jun 08, 2023

Click board™

Comparator Click

Development board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18LF47K42

Take control of your electrical systems with our comprehensive voltage comparison solution

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Hardware Overview

How does it work?

Comparator Click is based on the LM2903, a dual differential comparator from ON Semiconductor. These two independent voltage comparators allow the comparison of voltages near ground potential and are compatible with all forms of logic. The LM2903 has a low current drain with low input bias current, low input offset current, and low offset voltage with ±1mV. Two potentiometers have high shafts allowing easy usage, but they can also be used with a flat screwdriver. The potentiometers

can be used in correlation with the VR (voltage reference) screw terminals to set the threshold values for comparison with the obtained values over the IN (input) screw terminals with the common ground (GND) screw terminals. Comparator Click communicates with the host microcontroller with each output using its own interrupt pin on the mikroBUS™ socket labeled O1 and O2. In addition, every independent output has its own red HIGH and green LOW LEDs for visual

presentation, labeled LO1, HI1, LO2, and HI2. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the LOGIC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the 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.

Comparator Click hardware overview image

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC v8 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

EasyPIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

PIC18LF47K42

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

8192

Used MCU Pins

mikroBUS™ mapper

Comparator Output 1
RA2
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
RB0
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

Comparator Click Schematic schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

EasyPIC v8 front image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EasyPIC v8 Access DIPMB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
Necto image step 8 hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Comparator Click driver.

Key functions:

  • comparator_check_output_one - Check state of the OUT1 pin function.

  • comparator_check_output_two - Check state of the OUT2 pin 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 
 * \brief Comparator Click example
 * 
 * # Description
 * Comparator Click represents board equipped with two 
 * independent precise voltage comparators.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Application Init performs Logger and Click initialization.
 * 
 * ## Application Task  
 * Comparator click checks state of the O1 and O2 pins. 
 * Results are being sent to the UART Terminal 
 * where you can track their changes. 
 * All data logs write on USB UART and changes for every 1 sec.
 *  
 * \author Mihajlo Djordjevic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "comparator.h"

uint8_t out_state_one;
uint8_t out_state_two;

// ------------------------------------------------------------------ VARIABLES

static comparator_t comparator;
static log_t logger;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    comparator_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_printf( &logger, "--------------------------\r\n" );
    log_printf( &logger, "     Application  Init\r\n" );
    Delay_ms ( 500 );

    //  Click initialization.

    comparator_cfg_setup( &cfg );
    COMPARATOR_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    comparator_init( &comparator, &cfg );
    
    log_printf( &logger, "--------------------------\r\n" );
    log_printf( &logger, " --- Comparator Click --- \r\n" );
    log_printf( &logger, "--------------------------\r\n" );
    Delay_ms ( 1000 );
    
    log_printf( &logger, " -- Initialization done --\r\n" );
    log_printf( &logger, "--------------------------\r\n" );
    Delay_ms ( 1000 );
}

void application_task ( void )
{
    out_state_one = comparator_check_output_one( &comparator );
    out_state_two = comparator_check_output_two( &comparator );
    
    log_printf( &logger, "   Output One: \r\n" );
    
    if ( out_state_one )
    {
        log_printf( &logger, "   High \r\n" );
    }
    else
    {
        log_printf( &logger, "   Low \r\n" );
    }
    
    Delay_ms ( 500 );
    
    log_printf( &logger, "   Output Two: \r\n" );
    
    if ( out_state_two )
    {
        log_printf( &logger, "   High \r\n" );
    }
    else
    {
        log_printf( &logger, "   Low \r\n" );
    }
    
    Delay_ms ( 500 );
    
    log_printf( &logger, "--------------------------\r\n" );
    Delay_ms ( 1000 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources