Measure how bright the ambient light is in a given environment with PD15-22C/TR8 and ATmega328P
Manage and adjust lighting systems based on the surrounding light conditions
Published Feb 14, 2024
Click board™
Light Click
Dev. board
Arduino UNO Rev3
Compiler
NECTO Studio
MCU
ATmega328P
High-speed and highly sensitive photodiode specifically designed to detect light in both the visible and infrared spectrum
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Hardware Overview
How does it work?
Light Click is based on the PD15-22C/TR8, a high-speed, high-sensitive PIN photodiode from Everlight Electronics, effectively measuring ambient light intensity. This Click board™ is composed of a spectrometric photodiode to a visible and infrared emitting diode with a spectral range from 400 to 1100nm, an amplifier circuit, and an ADC to process the output signal in analog or digital form. The PD15-22C/TR8 has a fast response time with excellent responsivity close to the human eyes' response. It has stable performance over a wide temperature and voltage range and high
photosensitivity (940nm peak sensitivity) across various light sources suitable to sense the amount of the present ambient light. As mentioned, the output of the PD15-22C/TR8, in addition to the signal amplification by the operational amplifier LM358, can be converted to a digital value using MCP3201, a successive approximation A/D converter with a 12-bit resolution from Microchip using a 3-wire SPI compatible interface and a reference voltage set by MAX6106. Apart from the digital signal processing, the output of the PD15-22C/TR8 can be sent directly to an analog pin of
the mikroBUS™ socket labeled as AN. Selection can be performed by onboard SMD jumper labeled as OUTPUT, placing it in an appropriate position marked as AN or ADC. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the I/O level jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. However, the 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
Arduino UNO is a versatile microcontroller board built around the ATmega328P chip. It offers extensive connectivity options for various projects, featuring 14 digital input/output pins, six of which are PWM-capable, along with six analog inputs. Its core components include a 16MHz ceramic resonator, a USB connection, a power jack, an
ICSP header, and a reset button, providing everything necessary to power and program the board. The Uno is ready to go, whether connected to a computer via USB or powered by an AC-to-DC adapter or battery. As the first USB Arduino board, it serves as the benchmark for the Arduino platform, with "Uno" symbolizing its status as the
first in a series. This name choice, meaning "one" in Italian, commemorates the launch of Arduino Software (IDE) 1.0. Initially introduced alongside version 1.0 of the Arduino Software (IDE), the Uno has since become the foundational model for subsequent Arduino releases, embodying the platform's evolution.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
32
Silicon Vendor
Microchip
Pin count
28
RAM (Bytes)
2048
You complete me!
Accessories
Click Shield for Arduino UNO has two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the Arduino UNO board without effort. The Arduino Uno, a microcontroller board based on the ATmega328P, provides an affordable and flexible way for users to try out new concepts and build prototypes with the ATmega328P microcontroller from various combinations of performance, power consumption, and features. The Arduino Uno has 14 digital input/output pins (of which six can be used as PWM outputs), six analog inputs, a 16 MHz ceramic resonator (CSTCE16M0V53-R0), a USB connection, a power jack, an ICSP header, and reset button. Most of the ATmega328P microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the Arduino UNO board with our Click Shield for Arduino UNO, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
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 Arduino UNO Rev3 as your development board.
Software Support
Library Description
This library contains API for Light Click driver.
Key functions:
light_write_data- Generic write data functionlight_read_data- Generic read data functionlight_calculate_percent- Function calculate percent
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 Light Click example
*
* # Description
* This application return the ambient light intensity.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver enable's - SPI and start write log.
*
* ## Application Task
* This is a example which demonstrates the use of Light Click board.
* Measured light intensity and calculate light intensity percent from sensor,
* results are being sent to the Usart Terminal where you can track their changes.
* All data logs on usb uart for aproximetly every 100 ms when the data value changes.
*
*
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "light.h"
// ------------------------------------------------------------------ VARIABLES
static light_t light;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg;
light_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.
light_cfg_setup( &cfg );
LIGHT_MAP_MIKROBUS( cfg, MIKROBUS_1 );
light_init( &light, &cfg );
}
void application_task ( void )
{
uint16_t light_value;
uint8_t light_percent;
light_value = light_read_data( &light );
light_percent = light_calculate_percent( &light, light_value );
log_printf( &logger, " Light Intensity : %d \r\n", (uint16_t)light_percent );
log_printf( &logger, " Light Value : %d\r\n", light_value );
Delay_ms ( 1000 );
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
Additional Support
Resources
Category:Optical
