Intermediate
30 min
0

Provide highly accurate and responsive illumination adjustments with TSL2584TSV and PIC18LF27K42

Light as data: Unleashing the potential of ambient light sensing

Ambient 15 Click with Curiosity HPC

Published Jan 23, 2024

Click board™

Ambient 15 Click

Development board

Curiosity HPC

Compiler

NECTO Studio

MCU

PIC18LF27K42

Our ambient light sensor is the invisible hand behind a more efficient, comfortable, and sustainable future – discover the difference today

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Hardware Overview

How does it work?

Ambient 15 Click is based on the TSL2584TSV, a high-sensitivity light-to-digital converter that transforms light intensity into a digital output signal from AMS-AG. Thanks to its near-photopic response, the TSL2584TSV can detect a wide range of highly accurate lux measurements up to 33klx, even when mounted behind dark glass. Filtering out unwanted IR light enables the sensor to accurately measure the ambient light accurately, thus producing a near-photopic response. It also has stable performance over a wide temperature range, suitable for measuring the present ambient light. The TSL2584TSV combines one broadband photodiode (visible plus infrared), one infrared-responding photodiode, and, as mentioned before, a photopic infrared-blocking filter

on a single CMOS integrated circuit. Two integrating analog-to-digital converters (ADC) convert the photodiode currents into a digital output representing the irradiance measured on each channel. Integration of both channels occurs simultaneously. Upon completion of the conversion cycle, the conversion result is transferred to the Channel 0 and Channel 1 data registers. The transfers are double-buffered to ensure that the integrity of the data is maintained. After the transfer, the device automatically begins the next integration cycle. Ambient 15 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings, supporting Standard Mode operation with a clock frequency of 100kHz and Fast

Mode up to 400kHz. Besides, the TSL2584TSV allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labeled ADDR SEL. It also possesses an additional interrupt signal, routed on the INT pin of the mikroBUS™ socket labeled as INT, indicating when a specific interrupt event occurs, such as detecting a meaningful change in light intensity. This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. Also, it comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Ambient 15 Click top side image
Ambient 15 Click bottom side 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

default

Architecture

PIC

MCU Memory (KB)

128

Silicon Vendor

Microchip

Pin count

28

RAM (Bytes)

8192

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt
RB5
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
NC
NC
5V
Ground
GND
GND
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Take a closer look

Schematic

Ambient 15 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
IR Sense 4 Click front image hardware assembly
MCU DIP 28 hardware assembly
Prog-cut hardware assembly
Curiosity HPC 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 Ambient 15 Click driver.

Key functions:

  • ambient15_set_atime - This function sets the timing register for the selected integration time

  • ambient15_set_gain - This function sets the gain level

  • ambient15_measure_light_level - This function reads the raw ADC data from two channels and then measures the light level in lux based on those readings

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 Ambient15 Click example
 *
 * # Description
 * This example demonstrates the use of Ambient 15 click board by measuring 
 * the ambient light level in Lux.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 *
 * ## Application Task
 * Waits for the data ready interrupt, then reads the ambient light level in Lux
 * and displays the results on the USB UART. By default, the data ready interrupt triggers 
 * upon every ADC cycle which will be performed every 200ms.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "ambient15.h"

static ambient15_t ambient15;
static log_t logger;

void application_init ( void ) 
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    ambient15_cfg_t ambient15_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.
    ambient15_cfg_setup( &ambient15_cfg );
    AMBIENT15_MAP_MIKROBUS( ambient15_cfg, MIKROBUS_1 );
    if ( I2C_MASTER_ERROR == ambient15_init( &ambient15, &ambient15_cfg ) ) 
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( AMBIENT15_ERROR == ambient15_default_cfg ( &ambient15 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void ) 
{
    if ( !ambient15_get_int_pin ( &ambient15 ) )
    {
        uint16_t lux;
        if ( AMBIENT15_OK == ambient15_measure_light_level ( &ambient15, &lux ) )
        {
            log_printf ( &logger, " Ambient light level [Lux]: %u\r\n\n", lux );
        }
    }
}

void main ( void ) 
{
    application_init( );

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

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

Additional Support

Resources