Intermediate
30 min

Prevent damage from short circuits and reverse polarity with TPS25940 and ATmega1284

Power path defender: Where control meets reliability

eFuse 4 Click with EasyAVR v7

Published Oct 12, 2023

Click board™

eFuse 4 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega1284

Our eFuse solution is engineered to provide advanced circuit protection, offering precise current limiting, fault detection, and overcurrent protection for enhanced reliability and safety

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Hardware Overview

How does it work?

eFuse 4 Click is based on the TPS25940, a smart eFuse with integrated back-to-back FETs and enhanced built-in protection circuitry from Texas Instruments. The TPS25940 provides robust protection for all systems and applications powered by an external power supply from 2.7V to 18V. It also features a full suite of protection and monitoring functions, including a low-power DevSleep™ mode, controllable through a DVS pin routed on the PWM pin of the mikroBUS™ socket, that supports compliance with the SATA™ Device Sleep standard. This Click board™ is designed to protect systems such as enterprise SSD drives against sudden power loss events. It monitors voltages of the input and output terminals to provide true reverse blocking from the output

when a reverse condition or input power fail condition is detected. The TPS25940 allows users to program the overcurrent limit threshold between 1A and 5A via an external I2C-configurable digital potentiometer, the AD5272 from Analog Devices. Besides the overcurrent feature, the TPS25940 has programmable over and undervoltage thresholds for load, source, and device protection. The TPS25940 also provides an additional power-good comparator on the PGD pin, routed on the AN pin of the mikroBUS™ socket, with precision internal reference for output or any other rail voltage monitoring and a fault event indicator on the FLT pin. This fault indicator goes to a low logic state to indicate fault conditions due to under/overvoltage, reverse

voltage, and thermal shutdown events in the event of an overcurrent. A special addition on the plate represents an unpopulated header, which represents a precise current monitor output for health monitoring of the system, alongside the Enable pin routed on the RST pin of the mikroBUS™ socket that controls the ON/OFF state of the internal TPS25940’s FETs. 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.

eFuse 4 Click hardware overview image

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. 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, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR 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 a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V 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 which cover a wide range of 16-bit AVR MCUs. EasyAVR 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.

EasyAVR v7 horizontal image

Microcontroller Overview

MCU Card / MCU

ATmega1284

Architecture

AVR

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

16384

Used MCU Pins

mikroBUS™ mapper

Power-Good Indicator
PA7
AN
Reset
PA6
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
DevSleep Mode
PD4
PWM
Fault Interrupt
PD2
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PC0
SCL
I2C Data
PC1
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

eFuse 4 Click Schematic schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

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

EasyAVR v7 front image hardware assembly
GNSS2 Click front image hardware assembly
MCU DIP 40 hardware assembly
GNSS2 Click complete accessories setup image hardware assembly
EasyAVR v7 Access DIP 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 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

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 eFuse 4 Click driver.

Key functions:

  • efuse4_set_current_limit - eFuse 4 set current limit function

  • efuse4_set_resistance - eFuse 4 set resistance function

  • efuse4_set_digi_pot - eFuse 4 set normal mode function

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 eFuse 4 Click example
 *
 * # Description
 * This library contains API for the eFuse 4 Click driver.
 * This driver provides the functions to set the current limiting conditions 
 * in order to provide the threshold of the fault conditions.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initialization of I2C module and log UART.
 * After driver initialization, default settings turn on the device.
 *
 * ## Application Task
 * This example demonstrates the use of the eFuse 4 Click board™.
 * Reading user's input from UART Terminal and using it as an index 
 * for an array of pre-calculated values that define the current limit level.
 * Results are being sent to the UART Terminal, where you can track their changes.
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "efuse4.h"

static efuse4_t efuse4;
static log_t logger;

const efuse4_current_limit_t limit_value_op[ 7 ] = 
{ 
    EFUSE4_CURRENT_LIMIT_670_mA, 
    EFUSE4_CURRENT_LIMIT_750_mA,
    EFUSE4_CURRENT_LIMIT_990_mA,
    EFUSE4_CURRENT_LIMIT_2080_mA, 
    EFUSE4_CURRENT_LIMIT_3530_mA,
    EFUSE4_CURRENT_LIMIT_4450_mA,
    EFUSE4_CURRENT_LIMIT_5200_mA,
};

static void display_selection ( void ) 
{
    log_printf( &logger, "  To select current limit  \r\n" );
    log_printf( &logger, "  Send one of the numbers: \r\n" );
    log_printf( &logger, "- - - - - - - - - - - - - -\r\n" );
    log_printf( &logger, " '0' - Limited to  670 mA  \r\n" );
    log_printf( &logger, " '1' - Limited to  750 mA  \r\n" );
    log_printf( &logger, " '2' - Limited to  990 mA  \r\n" );
    log_printf( &logger, " '3' - Limited to 2080 mA  \r\n" );
    log_printf( &logger, " '4' - Limited to 3530 mA  \r\n" );
    log_printf( &logger, " '5' - Limited to 4450 mA  \r\n" );
    log_printf( &logger, " '6' - Limited to 5200 mA  \r\n" );  
    log_printf( &logger, "---------------------------\r\n" );
}

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    efuse4_cfg_t efuse4_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.
    efuse4_cfg_setup( &efuse4_cfg );
    EFUSE4_MAP_MIKROBUS( efuse4_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == efuse4_init( &efuse4, &efuse4_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( EFUSE4_ERROR == efuse4_default_cfg ( &efuse4 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
    log_printf( &logger, "---------------------------\r\n" );
    Delay_ms( 100 );
    
    display_selection( );
    Delay_ms( 100 );
}

void application_task ( void ) 
{  
    static char index;
    
    if ( EFUSE4_ERROR != log_read( &logger, &index, 1 ) ) 
    {
        if ( ( index >= '0' ) && ( index <= '6' ) ) 
        {
            efuse4_set_current_limit ( &efuse4, limit_value_op[ index - 48 ] );
            log_printf( &logger, "  >>> Selected mode %d     \r\n", index - 48 );
            log_printf( &logger, "  Current limit is %d mA   \r\n", limit_value_op[ index - 48 ] );
            log_printf( &logger, "---------------------------\r\n" );
            Delay_ms( 100 );
        }
        else 
        { 
            log_printf( &logger, "    Data not in range!    \r\n" );
            log_printf( &logger, "---------------------------\r\n" );
            display_selection( );
            Delay_ms( 100 );
        }
    }
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources

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