Experience the future of lighting innovation with MCP1643 and ATmega644
Light up your world!
Published Sep 04, 2023
Click board™
LED Driver 2 Click
Dev. board
EasyAVR v7
Compiler
NECTO Studio
MCU
ATmega644
With our LED driver solution and integrated LED, you can effortlessly enhance user experiences, create custom lighting effects, and ensure clear and intuitive status indications in your projects.
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Hardware Overview
How does it work?
LED driver 2 Click is based on the MCP1643, an LED constant current regulator from Microchip. It is a compact, high-efficiency, fixed frequency, synchronous step-up converter optimized to drive one LED with a constant current. It can be powered by a two-cell alkaline/NiMH/NiCd battery (2.4V) or via the mikroBUS™ power supply pins. LED Driver 2 click also features a 3W High-brightness LED by QT-Brightek. This LED can be dimmed by applying the variable duty cycle PWM signal to the EN pin of the MCP1643 regulator through the PWM pin of the mikroBUS™. MCP1643 is a boost regulator with a low voltage reference of 120mV (VFB). The main feature of the regulator is that it is optimized to keep the current running through the LED - constant by regulating the voltage across the feedback resistor. The VFB pin regulates the voltage across the feedback
resistor to 120 mV, keeping the output LED current regulated. As the feedback resistor (R2 on the provided schematic) is connected to the FB pin and its resistance is 0.4Ω, the maximum current through the LED can easily be calculated by using the following formula: ILED = VFB/R2 = 120mV/0.4Ω = 300mA. The voltage drop on the feedback resistor has to be low to avoid dissipation. In the case of MCP1643, this voltage is set to 120mV, ensuring no dissipation issues. The onboard VIN SEL SMD jumper offers the selection of the input voltage source: it can be set to use a two-cell NiMH battery connected to the VIN terminal (2.4V) or the power supply pin from the mikroBUS™. The voltage from the mikroBUS™ can be set with the VCCIO SMD jumper to either 5V or 3.3V. Since the forward voltage on the high-power LED is 3.2V, the click board comes equipped with the MCP1826,
an LDO regulator by Microchip, which is used to drop the selected mikroBUS™ voltage down to around 2.4V so that the MPC1643 input voltage requirements are met. High brightness 3W LED is already attached to the output of the MCP1643, and it comes soldered on the board, so the circuit is ready to be used immediately. The LED brightness can be regulated by applying a variable duty cycle PWM signal to the EN pin of the MCP1643 regulator (routed to the PWM pin on the mikroBUS™). This changes the current running through the LED linearly, from 0 to the value set by the resistor, depending on the PWM cycle. 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.
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.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
64
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
4096
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the EasyAVR v7 as your development board.
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 LED driver 2 Click driver.
Key functions:
leddriver2_set_duty_cycle- This function sets the PWM duty cycleleddriver2_pwm_stop- This function stops PWM moduleleddriver2_pwm_start- This function starts PWM module
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
* \brief LedDriver2 Click example
*
* # Description
* This app enables usage of compact, high-efficiency, fixed frequency,
* synchronous step-up converter, optimized to drive one LED with the constant current.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver enables - GPIO,
* PWM initialization set PWM duty cycle and start PWM.
*
* ## Application Task
* This is an example that demonstrates the use of the LED Driver 2 Click board.
* This example shows the automatic control halogen bulb light intensity,
* the first intensity of light is rising and then the intensity of light is falling.
* Results are being sent to the Usart Terminal where you can track their changes.
*
* \author Nikola Peric
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "leddriver2.h"
// ------------------------------------------------------------------ VARIABLES
static leddriver2_t leddriver2;
static log_t logger;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
leddriver2_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_info( &logger, "---- Application Init ----" );
// Click initialization.
leddriver2_cfg_setup( &cfg );
LEDDRIVER2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
leddriver2_init( &leddriver2, &cfg );
leddriver2_pwm_start( &leddriver2 );
}
void application_task ( void )
{
static int8_t duty_cnt = 1;
static int8_t duty_inc = 1;
float duty = duty_cnt / 10.0;
leddriver2_set_duty_cycle ( &leddriver2, duty );
log_printf( &logger, "> Duty: %d%%\r\n", ( uint16_t )( duty_cnt * 10 ) );
Delay_ms( 500 );
if ( 10 == duty_cnt )
{
duty_inc = -1;
}
else if ( 0 == duty_cnt )
{
duty_inc = 1;
}
duty_cnt += duty_inc;
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
