Intermediate
30 min

Optimize your systems, enhance safety, and achieve reliability with MAX17608 and ATmega1284

Empowering innovation, one Amp at a time

Current Limit 6 Click with EasyAVR v7

Published Oct 12, 2023

Click board™

Current Limit 6 Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega1284

Our current limiting solution is engineered to revolutionize safety and efficiency, offering precise control over current to ensure optimal performance while safeguarding your systems against overloads

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Hardware Overview

How does it work?

Current Limit 6 Click is based on the MAX17608, a current-limiting device with an adjustable overvoltage and overcurrent protection feature from Analog Devices. The MAX17608 offers flexible protection boundaries for systems against input voltage ranging from 4.5V to 60V and limits the output load current to a programmed level (up to 1A). The devices also feature two internal MOSFETs connected in series, with a low cumulative RON of 260mΩ typical. Input undervoltage protection can be programmed between 4.5V and 59V, while the overvoltage protection can be independently programmed between 5.5V and 60V (default Click board™ configuration is 4.5V for UVLO and 14V for OVLO). Additionally, the MAX17608 has an internal default undervoltage lockout set at 4V typical. The current-limit switch is virtually ubiquitous in system control and provides a safe means for regulating the current delivered to a load circuit. It increases the load current to a programmed limit but no higher. Typically, the current limit is a

function of the voltage across an external resistor, and this voltage serves as the reference for an internal current-limiting amplifier. Replacing the resistor with a digital potentiometer allows you to program the current limit as performed on this Click board™. For this purpose, the digital potentiometer MAX5401 from Analog Devices, which communicates with the MCU via a 3-wire SPI serial interface, is used to set the resistance on the MAX17608 SETI pin, adjusting the current limit for the switch between 0.1A to 1 A. This current limiter offers several operational modes, selectable through a populated jumper labeled as R11 connected to the CLMD pin of the MAX17608. In a default configuration, this pin is connected to the ground, representing the Continuous mode of operation. When R11 is replaced with a 150kΩ resistor, this Click board™ is in the Latch-off mode, and when the user leaves this pin unconnected, Autoretry mode of operation is activated. More information on the operational modes

can be found in the attached datasheet. Current Limit 6 Click can be turned on, or off through the EN pin routed to the PWM pin of the mikroBUS™ socket, hence offering a switch operation to turn ON/OFF power delivery to the connected load. It also provides communication signals routed to the INT and AN pins of the mikroBUS™ socket, alongside its LED indicators, labeled ER1 and ER2, to indicate different operational and fault signals, such as FLAG and UVOV signals. Besides, the MAX17608 also offers internal thermal shutdown protection against excessive power dissipation. 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.

Current Limit 6 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

UVLO/OVLO Indicator
PA7
AN
NC
NC
RST
SPI Chip Select
PA5
CS
SPI Clock
PB7
SCK
NC
NC
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
Enable
PD4
PWM
Fault Interrupt
PD2
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

Click board™ Schematic

Current Limit 6 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 Current Limit 6 Click driver.

Key functions:

  • currentlimit6_set_current_limit - Current Limit 6 set current limit function

  • currentlimit6_power_mode - Current Limit 6 power mode function

  • currentlimit6_check_limit_exceeded - Current Limit 6 check limit exceeded 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 CurrentLimit6 Click example
 *
 * # Description
 * This library contains API for the Current Limit 6 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 SPI module and log UART.
 * After driver initialization, default settings turn on the device.
 *
 * ## Application Task
 * This example demonstrates the use of the Current Limit 6 Click board™.
 * Reading user's input from Usart 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 Usart Terminal, where you can track their changes.
 *
 * ## Additional Function
 * - static void display_selection ( void )
 *
 * @author Nenad Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "currentlimit6.h"

static currentlimit6_t currentlimit6;
static log_t logger;
const float limit_value[ 9 ] = { 0.100, 0.200, 0.300, 0.400, 0.500, 0.600, 0.700, 0.800, 0.999 };

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, " '1' - Limited to 100 mA  \r\n" );
    log_printf( &logger, " '2' - Limited to 200 mA  \r\n" );
    log_printf( &logger, " '3' - Limited to 300 mA  \r\n" );
    log_printf( &logger, " '4' - Limited to 400 mA  \r\n" );
    log_printf( &logger, " '5' - Limited to 500 mA  \r\n" );
    log_printf( &logger, " '6' - Limited to 600 mA  \r\n" );
    log_printf( &logger, " '7' - Limited to 700 mA  \r\n" );
    log_printf( &logger, " '8' - Limited to 800 mA  \r\n" );
    log_printf( &logger, " '9' - Limited to 999 mA  \r\n" );
    log_printf( &logger, "--------------------------\r\n" );
}

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    currentlimit6_cfg_t currentlimit6_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.
    currentlimit6_cfg_setup( &currentlimit6_cfg );
    CURRENTLIMIT6_MAP_MIKROBUS( currentlimit6_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == currentlimit6_init( &currentlimit6, &currentlimit6_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( CURRENTLIMIT6_ERROR == currentlimit6_default_cfg ( &currentlimit6 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "  Current Limit 6 Click  \r\n" );
    log_printf( &logger, "-------------------------\r\n" );
    log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
    Delay_ms( 100 );
    
    display_selection( );
    Delay_ms( 100 );
}

void application_task ( void )
{ 
    static char index;
    
    if ( log_read( &logger, &index, 1 ) != CURRENTLIMIT6_ERROR ) 
    {
        if ( ( index >= '1' ) && ( index <= '9' ) ) 
        {
            currentlimit6_set_current_limit ( &currentlimit6, limit_value[ index - 49 ] );
            log_printf( &logger, "  >>> Selected mode %d     \r\n", index - 48 );
            log_printf( &logger, "- - - - - - - - - - - - -\r\n" );
            log_printf( &logger, " Current limit is %.3f A \r\n", limit_value[ index - 49 ] );
            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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