30 min

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Current Limit 5 Click with Curiosity HPC

Published Jan 23, 2024

Click board™

Current Limit 5 Click

Dev Board

Curiosity HPC


NECTO Studio



Experience the future of confident current management with our solution, where precision ensures optimal performance and efficiency, while protecting your systems from potential overloads



Hardware Overview

How does it work?

Current Limit 5 Click is based on the MIC2099, a current-limiting device with an adjustable overcurrent protection feature from Microchip Technology. The MIC2099 offers flexible protection boundaries for systems against input voltage ranging from 2.5V to 5.5V and limits the output load current to a programmed level (up to 1.05A). Additional safety features include thermal shutdown protection to prevent overheating, under-voltage lock-out, a soft start that prevents large current inrush, and automatic-on output after a fault condition. 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 MCP4561 from Microchip Technology, which communicates with the MCU via a 2-wire I2C serial interface, is used to set the resistance on the MIC2099 LIMIT pin, adjusting the current limit for the switch between 0.1A to 1.05A. Current Limit 5 Click can be turned on, or off through the EN pin routed to the CS pin of the mikroBUS™ socket, hence offering a switch operation to turn ON/OFF power delivery to the connected load. It also provides a fault status indication signal, labeled as FLT and routed to the INT pin of the mikroBUS™ socket, alongside its

LED indicator marked as FAULT to indicate different fault conditions such as current limit and thermal shutdown. This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows both 3.3V and 5V capable MCUs to use the communication lines properly. Additionally, there is a possibility for the MIC2099 power supply selection via jumper labeled as VIN SEL to supply the MIC2099 from an external power supply VEXT terminal in the range from 2.5V to 5.5V or with VCC voltage levels from mikroBUS™ power rails. 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 5 Click hardware overview image

Features overview

Development board

Curiosity HPC, standing for Curiosity High Pin Count (HPC) development board, supports 28- and 40-pin 8-bit PIC MCUs specially designed by Microchip for the needs of rapid development of embedded applications. This board has two unique PDIP sockets, surrounded by dual-row expansion headers, allowing connectivity to all pins on the populated PIC MCUs. It also contains a powerful onboard PICkit™ (PKOB), eliminating the need for an external programming/debugging tool, two mikroBUS™ sockets for Click board™ connectivity, a USB connector, a set of indicator LEDs, push button switches and a variable potentiometer. All

these features allow you to combine the strength of Microchip and Mikroe and create custom electronic solutions more efficiently than ever. Each part of the Curiosity HPC development board contains the components necessary for the most efficient operation of the same board. An integrated onboard PICkit™ (PKOB) allows low-voltage programming and in-circuit debugging for all supported devices. When used with the MPLAB® X Integrated Development Environment (IDE, version 3.0 or higher) or MPLAB® Xpress IDE, in-circuit debugging allows users to run, modify, and troubleshoot their custom software and hardware

quickly without the need for additional debugging tools. Besides, it includes a clean and regulated power supply block for the development board via the USB Micro-B connector, alongside all communication methods that mikroBUS™ itself supports. Curiosity HPC development board allows you to create a new application in just a few steps. Natively supported by Microchip software tools, it covers many aspects of prototyping thanks to many number of different Click boards™ (over a thousand boards), the number of which is growing daily.

Curiosity HPC double image

Microcontroller Overview

MCU Card / MCU




MCU Memory (KB)


Silicon Vendor


Pin count


RAM (Bytes)


Used MCU Pins

mikroBUS™ mapper

Power Supply
Fault Interrupt
I2C Clock
I2C Data
Power Supply

Take a closer look


Current Limit 5 Click Schematic schematic

Step by step

Project assembly

Curiosity HPC front no-mcu image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity HPC as your development board.

Curiosity HPC front no-mcu image hardware assembly
LTE Cat.1 2 Click front image hardware assembly
MCU DIP 28 hardware assembly
Prog-cut hardware assembly
LTE Cat.1 2 Click complete accessories setup image hardware assembly
Curiosity HPC Access 28pin-DIP - 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
Necto DIP image step 7 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

After loading the code example, pressing the "DEBUG" button builds and programs it on the selected setup.

Application Output Step 1

After programming is completed, a header with buttons for various actions available in the IDE appears. By clicking the green "PLAY "button, we start reading the results achieved with Click board™.

Application Output Step 3

Upon completion of programming, the Application Output tab is automatically opened, where the achieved result can be read. In case of an inability to perform the Debug function, check if a proper connection between the MCU used by the setup and the CODEGRIP programmer has been established. A detailed explanation of the CODEGRIP-board connection can be found in the CODEGRIP User Manual. Please find it in the RESOURCES section.

Application Output Step 4

Software Support

Library Description

This library contains API for Current Limit 5 Click driver.

Key functions:

  • currentlimit5_set_ilimit - This function sets the current limit value by configuring the onboard digital potentiometer

  • currentlimit5_get_fault_pin - This function returns the fault pin logic state

  • currentlimit5_enable_limit - This function enables the current limiting switch

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 main.c
 * @brief CurrentLimit5 Click example
 * # Description
 * This example demonstrates the use of Current Limit 5 click board by limiting
 * the current to a certain value and displaying an appropriate message when the current
 * reaches the limit.
 * The demo application is composed of two sections :
 * ## Application Init
 * Initializes the driver and performs the click default configuration which sets
 * the current limit to 200mA.
 * ## Application Task
 * Displays the fault indicator state on the USB UART.
 * @author Stefan Filipovic

#include "board.h"
#include "log.h"
#include "currentlimit5.h"

static currentlimit5_t currentlimit5;
static log_t logger;

void application_init ( void ) 
    log_cfg_t log_cfg;  /**< Logger config object. */
    currentlimit5_cfg_t currentlimit5_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.
    currentlimit5_cfg_setup( &currentlimit5_cfg );
    CURRENTLIMIT5_MAP_MIKROBUS( currentlimit5_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == currentlimit5_init( &currentlimit5, &currentlimit5_cfg ) ) 
        log_error( &logger, " Communication init." );
        for ( ; ; );
    if ( CURRENTLIMIT5_ERROR == currentlimit5_default_cfg ( &currentlimit5 ) )
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    log_info( &logger, " Application Task " );

void application_task ( void ) 
    static uint8_t currentlimit_ind = 2;
    if ( currentlimit5_get_fault_pin ( &currentlimit5 ) )
        if ( currentlimit_ind != 0 )
            log_printf ( &logger, " The switch is in normal operation \r\n\n" );
            currentlimit_ind = 0;
        if ( currentlimit_ind != 1 )
            log_printf ( &logger, " The switch is in the current limiting or thermal shutdown operation \r\n\n" );
            currentlimit_ind = 1;

void main ( void ) 
    application_init( );

    for ( ; ; ) 
        application_task( );

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

Additional Support