Measure how bright the ambient light is in a given environment with PD15-22C/TR8 and PIC32MZ2048EFM100

Manage and adjust lighting systems based on the surrounding light conditions

Published Jan 31, 2024

Click board™

Light Click

Dev. board

Curiosity PIC32 MZ EF

Compiler

NECTO Studio

MCU

PIC32MZ2048EFM100

High-speed and highly sensitive photodiode specifically designed to detect light in both the visible and infrared spectrum

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

Curiosity PIC32 MZ EF development board is a fully integrated 32-bit development platform featuring the high-performance PIC32MZ EF Series (PIC32MZ2048EFM) that has a 2MB Flash, 512KB RAM, integrated FPU, Crypto accelerator, and excellent connectivity options. It includes an integrated programmer and debugger, requiring no additional hardware. Users can expand

functionality through MIKROE mikroBUS™ Click™ adapter boards, add Ethernet connectivity with the Microchip PHY daughter board, add WiFi connectivity capability using the Microchip expansions boards, and add audio input and output capability with Microchip audio daughter boards. These boards are fully integrated into PIC32’s powerful software framework, MPLAB Harmony,

which provides a flexible and modular interface to application development a rich set of inter-operable software stacks (TCP-IP, USB), and easy-to-use features. The Curiosity PIC32 MZ EF development board offers expansion capabilities making it an excellent choice for a rapid prototyping board in Connectivity, IOT, and general-purpose applications.

Microcontroller Overview

MCU Card / MCU

Architecture

PIC32

MCU Memory (KB)

2048

Silicon Vendor

Microchip

Pin count

100

RAM (Bytes)

524288

Used MCU Pins

mikroBUS™ mapper

Analog Output

RPB4

RST

SPI Chip Select

RPD4

SPI Clock

RPD1

SCK

SPI Data OUT

RPD14

MISO

MOSI

Power Supply

3.3V

Ground

GND

PWM

INT

SCL

SDA

Power Supply

Ground

GND

Take a closer look

Click board™ Schematic

Step by step

Project assembly

Curiosity PIC32MZ EF front image hardware assembly

Start by selecting your development board and Click board™. Begin with the Curiosity PIC32 MZ EF as your development board.

Thermo 28 Click front image hardware assembly

Curiosity PIC32 MZ EF MB 1 - upright/background hardware assembly

Curiosity PIC32 MZ EF MCU Step hardware assembly

Necto No Display image step 8 hardware assembly

Debug Image Necto Step 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 Light Click driver.

Key functions:

light_write_data - Generic write data function
light_read_data - Generic read data function
light_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 );

}

void main ( void )
{
    application_init( );

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


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