Intermediate
30 min
0

Monitor smoke levels and conditions remotely using the MAX30105 and PIC18F45K40

Clearing the air: The future of smoke detection and prevention

Smoke Click with EasyPIC v7

Published Sep 19, 2023

Click board™

Smoke Click

Development board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18F45K40

Discover how our advanced smoke detection solution enhances your ability to prevent and mitigate fire risks, creating safer environments for everyone

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Hardware Overview

How does it work?

Smoke Click is based on the MAX30105, a high-sensitivity optical sensor for smoke detection applications from Analog Devices. The sensor is an integrated particle-sensing module with internal LEDs, photodetectors, optical elements, and low-noise electronics with ambient light rejection. To detect the smoke, the MAX30105 senses the light of LEDs that are rejected from the smoke particles by the photodetectors. The particle-sensing subsystem contains ambient light cancellation (ALC), a continuous-time sigma-delta 18-bit ADC, and a proprietary discrete time filter. The ALC has an internal track/hold circuit to cancel ambient light and increase dynamic range. The ADC output data rate can be programmed from 50sps to 3200sps. The MAX30105 integrates red, green, and IR LED drivers to modulate LED pulses for

particle-sensing measurements. The LED current can be programmed from 0 up to 50mA. The onboard temperature sensor is used for calibrating the temperature dependence of the particle-sensing subsystem. This temperature sensor has an inherent resolution of 0.0625°C. After the particle-sensing initiation, the IR LED is activated in proximity mode; when an object is detected, it goes automatically to the normal mode. The proximity mode can be re-entered. Smoke Click uses a standard 2-Wire I2C interface to communicate with the host MCU, supporting the clock data rates up to 400KHz. The sensor uses 1.8V for a power supply, which on this Click board™ is available over the SPX3819MS, a 500mA low-noise LDO voltage regulator from MaxLinear. For this sensor to work with higher logic levels,

Smoke Click features the PCA9306, a dual bidirectional I2C bus, and an SMBus voltage-level translator from Texas Instruments. One of the available interrupt statuses can be received over the INT pin and the SN74LVC1T45, a single-bit dual-supply bus transceiver with configurable voltage translation and 3-state outputs from Texas Instruments. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. 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.

Smoke Click top side image
Smoke Click bottom side image

Features overview

Development board

EasyPIC v7 is the seventh generation of PIC development boards specially designed to develop embedded applications rapidly. It supports a wide range of 8-bit PIC microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB-B. 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, EasyPIC v7 allows you to connect accessory boards, sensors, and custom electronics more efficiently than ever. Each part of

the EasyPIC 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 various external power sources, including an external 12V power supply, 7-23V AC or 9-32V 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. These sockets cover a wide range of 8-bit PIC MCUs, from PIC10F, PIC12F, PIC16F, PIC16Enh, PIC18F, PIC18FJ, and PIC18FK families. EasyPIC 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.

EasyPIC v7 horizontal image

Microcontroller Overview

MCU Card / MCU

PIC18F45K40

Architecture

PIC

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

2048

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
RB0
INT
NC
NC
TX
NC
NC
RX
I2C Clock
RC3
SCL
I2C Data
RC4
SDA
Power Supply
5V
5V
Ground
GND
GND
1

Take a closer look

Schematic

Smoke Click Schematic schematic

Step by step

Project assembly

EasyPIC v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v7 as your development board.

EasyPIC v7 front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyPIC v7 MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

Track your results in real time

Application Output

After pressing the "FLASH" button on the left-side panel, it is necessary to open the UART terminal to display the achieved results. By clicking on the Tools icon in the right-hand panel, multiple different functions are displayed, among which is the UART Terminal. Click on the offered "UART Terminal" icon.

UART Application Output Step 1

Once the UART terminal is opened, the window takes on a new form. At the top of the tab are two buttons, one for adjusting the parameters of the UART terminal and the other for connecting the UART terminal. The tab's lower part is reserved for displaying the achieved results. Before connecting, the terminal has a Disconnected status, indicating that the terminal is not yet active. Before connecting, it is necessary to check the set parameters of the UART terminal. Click on the "OPTIONS" button.

UART Application Output Step 2

In the newly opened UART Terminal Options field, we check if the terminal settings are correct, such as the set port and the Baud rate of UART communication. If the data is not displayed properly, it is possible that the Baud rate value is not set correctly and needs to be adjusted to 115200. If all the parameters are set correctly, click on "CONFIGURE".

UART Application Output Step 3

The next step is to click on the "CONNECT" button, after which the terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART Application Output Step 4

Software Support

Library Description

This library contains API for Smoke Click driver.

Key functions:

  • smoke_set_registers - Set registers values function

  • smoke_enable_disable_interrupts - Enable or disable interrupt function

  • smoke_read_leds - Function for reading enabled led values

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 
 * \brief Smoke Click example
 * 
 * # Description
 * This click includes internal LEDs, photodetectors, optical elements, and low-noise electronics 
 * with ambient light rejection. The sensor can detect a wide variety of smoke particle sizes. 
 * It also has an on-chip temperature sensor for calibrating the temperature dependence of the 
 * particle sensing subsystem. The temperature sensor has an inherent resolution 0.0625°C.
 *
 * 
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initalizes I2C driver, applies "set registers check green values" settings, 
 * "enable FIFO data ready interrupt" and makes an initial log.
 * 
 * ## Application Task  
 * This example demonstrates the use of Smoke Click board. It reads reflected green values and
 * temperature from an internal sensor and displays the results on USART terminal.
 * It usualy takes two or three readings in order to get corect readings. Expect big values when you do.
 * 
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "smoke.h"

// ------------------------------------------------------------------ VARIABLES

static smoke_t smoke;
static log_t logger;

static float temperature;

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    smoke_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.

    smoke_cfg_setup( &cfg );
    SMOKE_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    smoke_init( &smoke, &cfg );

    smoke_reset( &smoke );
    smoke_default_cfg ( &smoke );

    log_info( &logger, "---- Application Task ----" );
    Delay_ms( 100 );
    if ( smoke_read_leds( &smoke ) != SMOKE_OK )
    {
        log_info( &logger, "---- Init Error ----" );
        for( ; ; );
    }
}

void application_task ( void )
{
    smoke_read_leds( &smoke );
    
    log_printf( &logger, "Red : %llu\r\n", smoke.red_value );
    log_printf( &logger, "IR : %llu\r\n", smoke.ir_value );
    log_printf( &logger, "Green : %llu\r\n", smoke.green_value );
    log_printf( &logger, "------------------------------\r\n" );
    
    temperature = smoke_read_temp( &smoke );
    
    log_printf( &logger, "Read Temperature[ degC ]: %.2f\r\n",  temperature );
    log_printf( &logger, "------------------------------\r\n" );

    Delay_ms( 1000 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources