Intermediate
30 min
0

Experience the voltage step-down elegance with BMR4613001/001 and PIC18LF25K40

Synchronous step-down beast!

Buck 14 Click with EasyPIC v7

Published Dec 29, 2023

Click board™

Buck 14 Click

Development board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18LF25K40

Through its ability to step down voltages with exceptional efficiency, our buck converter also contributes to a greener and more sustainable future by conserving energy resources

A

A

Hardware Overview

How does it work?

Buck 14 Click is based on the BMR4613001/001 - a PoL regulator from Flex that incorporates a wide range of readable and configurable power management features that are simple to implement with a minimum of external components. Additionally, it includes protection features that continuously safeguard the load from damage due to unexpected system faults. A fault is also shown as an alert on the ALR pin of the mikroBUS™ socket. The product is delivered with a default configuration suitable for various operations regarding input voltage, output voltage, and load. The configuration is stored in an internal Non-Volatile Memory (NVM). All power management functions can be reconfigured using the PMBus interface. It is possible to monitor various parameters through the PMBus interface. Fault conditions can be monitored using the

ALERT pin, which will be asserted when any pre-configured fault or warning conditions occur. The Buck 14 click supports tracking the output from a master voltage applied to the VTRK pin of BMR4613001/001. To select the tracking mode, a resistance ≤ 4.22 kΩ must be connected between the VSET and PREF pins (RS resistor). The tracking ratio is controlled by an internal feedback divider RDIV and an external resistive voltage divider (R3, R2, not populated on the board) placed from the supply being tracked to GND pins. Unlike PID-based digital power regulators, the product uses a state-space model-based algorithm valid for both the small- and large-signal response and accounts for duty-cycle saturation effects. This eliminates the need for users to determine and set thresholds for transitioning from linear to nonlinear modes. These capabilities result in a fast loop transient

response and the possibility of reducing the number of output capacitors. The product features a remote control input through the EN pin and a PMBus enable function by the command OPERATION to control the output voltage. It is also possible to configure the output to be always on. By default, the output is controlled by the EN pin only. The output voltage control can be reconfigured using the PMBus command ON_OFF_CONFIG. It is designed to operate in different thermal environments, and sufficient cooling must ensure reliable operation. Cooling is achieved mainly by conduction, from the pins to the host board, and convection, which depends on the product's airflow. Increased airflow enhances the cooling of the product.

Buck 14 Click hardware overview image

Features overview

Development board

EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyPIC v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use various external power sources, including an external 12V power supply, 7-23V AC or 9-32V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B) connector. Communication options such as

USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC v7 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 v7 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

PIC

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

2048

Used MCU Pins

mikroBUS™ mapper

Power Good Indicator
RA3
AN
NC
NC
RST
Enable
RA5
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Sync
RC1
PWM
Alert
RB1
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
NC
NC
5V
Ground
GND
GND
2

Take a closer look

Schematic

Buck 14 Click Schematic schematic

Step by step

Project assembly

EasyPIC v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7 as your development board.

EasyPIC v7 front image hardware assembly
LTE IoT 5 Click front image hardware assembly
MCU DIP 28 hardware assembly
LTE IoT 5 Click complete accessories setup image hardware assembly
EasyPIC v7 Access MB 2 - 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
EasyPIC PRO v7a Display Selection Necto Step 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 Buck 14 Click driver.

Key functions:

  • buck14_power_ctrl - This function sets state of the power control pin

  • buck14_salert - This function gets manufacturer ID

  • buc14_write_vout - This function sets output voltage

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 Buck14 Click example
 * 
 * # Description
 * This app enables usage of high-efficiency step-down converter.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Configure device.
 * 
 * ## Application Task  
 * Sends 4 different commands for VOUT in span of 8sec
 * 
 * *note:* 
 * When you send data you should send LSB first.
 * Device input V should be beetween 4.5 - 14 V.
 * Device output V could be from 0.5 - 5 V deepending from limits you set currently it is set to 1V.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "buck14.h"

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

static buck14_t buck14;
static log_t logger;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

void error_handler ( uint8_t stat_data )
{
    if ( stat_data == BUCK14_ERROR )
    {
        log_printf( &logger, "ERROR! \r\n " );
        for ( ; ; );
    }
    else if ( stat_data == BUCK14_ID_ERROR )
    {
        log_printf( &logger, "ID ERROR! \r\n " );
        for ( ; ; );
    }
    else if ( stat_data == BUCK14_CMD_ERROR )
    {
        log_printf( &logger, "CMD ERROR! \r\n " );
    }
}

void read_vout_data ( buck14_t *ctx )
{
    uint16_t temp_data;

    temp_data = buc14_read_vout( &buck14 );
    log_printf( &logger, "VOUT ~ %u mV \r\n", temp_data );
}

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

void application_init ( void )
{
    log_cfg_t log_cfg;
    buck14_cfg_t cfg;
    uint8_t write_data;
    uint8_t status_data;

    /** 
     * 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.

    buck14_cfg_setup( &cfg );
    BUCK14_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    buck14_init( &buck14, &cfg );

    buck14_reset( &buck14 );

    write_data  = BUCK14_CTRL_ENABLE_NO_MARGIN;
    buck14_generic_write( &buck14, BUCK14_CMD_OPERATION, &write_data , 1 );
    Delay_ms( 300 );

    status_data = buck14_check_mfr_id(  &buck14 );
    error_handler( status_data );
    log_printf( &logger, "-Device ID OK!\r\n" );
    
    buck14_power_ctrl( &buck14, BUCK14_PIN_STATE_HIGH );

    buck14_default_cfg( &buck14 );
    log_printf( &logger, " ***** App init ***** \r\n" );
    log_printf( &logger, "----------------------\r\n" );
    Delay_ms( 100 );
}

void application_task ( void )
{
    uint8_t status_data;
    float vout_value;

    vout_value = 1.2;
    status_data = buc14_write_vout( &buck14, vout_value );
    error_handler( status_data );

    if ( status_data == BUCK14_SUCCESSFUL )
    {
        read_vout_data(  &buck14 );
    }
    Delay_ms( 8000 );

    vout_value = 3.7;
    status_data = buc14_write_vout( &buck14, vout_value );
    error_handler( status_data );

    if ( status_data == BUCK14_SUCCESSFUL )
    {
        read_vout_data( &buck14 );
    }

    Delay_ms( 8000 );

    vout_value = 2.5;
    status_data = buc14_write_vout( &buck14, vout_value );
    error_handler( status_data );

    if ( status_data == BUCK14_SUCCESSFUL )
    {
        read_vout_data(  &buck14 );
    }
    
    Delay_ms( 8000 );

    vout_value = 4.5;
    status_data = buc14_write_vout(  &buck14, vout_value );
    error_handler( status_data );

    if ( status_data == BUCK14_SUCCESSFUL )
    {
        read_vout_data(  &buck14 );
    }
    
    Delay_ms( 4000 );
    log_printf( &logger, "```````````````\r\n" );
    Delay_ms( 4000 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources