Recognize the following gestures with MAX25405 and PIC18F26K80

Contactless gesture recognition

Published Nov 01, 2023

Click board™

IR Gesture 2 Click

Dev Board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18F26K80

One solution for proximity, hand detection, and gesture recognition

Hardware Overview

How does it work?

IR Gesture 2 Click is based on the MAX25405 data-acquisition system from Analog Devices for gesture and proximity sensing. This Click board™ represents an infrared-based dynamic optical solution that can sense a broader range of motions at extended distances. The MAX25405 detects wider movement proximity and doubles the sensing range to 40cm compared to earlier generations. It recognizes the following independent gestures: hand swipe (left, right, up, down, wave), air click and flicks, finger and hand rotation (clockwise and counter-clockwise), and multizone proximity detection. Along with integrated optics and a 6x10 infrared sensor array, the MAX25405 also includes a glass lens,

increasing sensitivity and improving the signal-to-noise ratio. The proximity, hand detection, and gesture recognition functions of the MAX25405 operate by detecting the light reflected from the controlled IR-LED light sources (SFH 4248-VAW and SFH 4249-UV) driven directly from the MAX25405. It can also detect these gestures even when exposed to bright ambient light and process data from the sensor through a serial interface. The light source PWM duty cycle is programmable from 1/16 to 16/16, where LEDs are pulsed one or more times in a programmable sequence repeated for every sample. IR Gesture 2 Click communicates with MCU using the 12-bit SPI serial interface compatible with

standard SPI, QSPI™, MICROWIRE™, and digital signal processors (DSPs), with a maximum frequency of 6MHz. This Click board™ also possesses an additional interrupt pin, routed to the INT pin on the mikroBUS™ socket, indicating when a specific interrupt event occurs, such as the end of a conversation sample sequence. This Click board™ can only be operated with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before using MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used as a reference for further development.

Features overview

Development board

EasyPIC v8 is a development board specially designed for the needs of rapid development of embedded applications. It supports many high pin count 8-bit PIC microcontrollers from Microchip, regardless of their number of pins, and a broad set of unique functions, such as the first-ever embedded debugger/programmer. The development board is well organized and designed so that the end-user has all the necessary elements, such as switches, buttons, indicators, connectors, and others, in one place. Thanks to innovative manufacturing technology, EasyPIC v8 provides a fluid and immersive working experience, allowing access anywhere and under any

circumstances at any time. Each part of the EasyPIC v8 development board contains the components necessary for the most efficient operation of the same board. In addition to the advanced integrated CODEGRIP programmer/debugger module, which offers many valuable programming/debugging options and seamless integration with the Mikroe software environment, the board also includes a clean and regulated power supply module for the development board. It can use a wide range of external power sources, including a battery, an external 12V power supply, and a power source via the USB Type-C (USB-C) connector.

Communication options such as USB-UART, USB DEVICE, and CAN are also included, including the well-established mikroBUS™ standard, two display options (graphical and character-based LCD), and several different DIP sockets. These sockets cover a wide range of 8-bit PIC MCUs, from the smallest PIC MCU devices with only eight up to forty pins. EasyPIC v8 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

PIC

MCU Memory (KB)

Silicon Vendor

Microchip

Pin count

RAM (Bytes)

3648

Used MCU Pins

mikroBUS™ mapper

RST

SPI Chip Select

RA5

SPI Clock

RC3

SCK

SPI Data OUT

RC4

MISO

SPI Data IN

RC5

MOSI

Power Supply

3.3V

Ground

GND

PWM

Interrupt

RB1

INT

SCL

SDA

Ground

GND

Take a closer look

Schematic

Step by step

Project assembly

EasyPIC v8 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyPIC v8 as your development board.

NECTO Output Selection Step Image hardware assembly

In the advanced settings, pay special attention to the Redirect standard output field. By default, it is set to Application output as the method of displaying final results. To show results via a UART terminal, select the “UART” option in that field and click the “SAVE” button. You will be returned to the Compiler field, and now you can move on to the next step by pressing the “NEXT” button.

Rotary B 2 Click front image hardware assembly

EasyPIC v8 28pin-DIP - upright/background hardware assembly

NECTO Compiler Selection Step Image hardware assembly

Necto DIP image step 7 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.

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.

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".

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.

Software Support

Library Description

This library contains API for IR Gesture 2 Click driver.

Key functions:

irgesture2_get_int_pin This function returns the INT pin logic state.
irgesture2_read_pixels This function reads the raw ADC values of entire 60-pixel IR photodiode array.
irgesture2_write_register This function writes a data byte to the selected register by using SPI serial interface.

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 IRGesture2 Click example
 *
 * # Description
 * This example demonstrates the use of IR Gesture 2 click board by reading and displaying
 * the raw ADC values of entire 60-pixel IR photodiode array.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver and performs the click default configuration.
 *
 * ## Application Task
 * Waits for an end of conversion interrupt and then reads the raw ADC values of entire
 * 60-pixel IR photodiode array and displays the results on the USB UART as a 10x6 matrix
 * every 100ms approximately.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "irgesture2.h"

static irgesture2_t irgesture2;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    irgesture2_cfg_t irgesture2_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.
    irgesture2_cfg_setup( &irgesture2_cfg );
    IRGESTURE2_MAP_MIKROBUS( irgesture2_cfg, MIKROBUS_1 );
    if ( SPI_MASTER_ERROR == irgesture2_init( &irgesture2, &irgesture2_cfg ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( IRGESTURE2_ERROR == irgesture2_default_cfg ( &irgesture2 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    // Wait for an end of conversion interrupt
    while ( irgesture2_get_int_pin ( &irgesture2 ) );
    
    int16_t pixels[ IRGESTURE2_NUM_SENSOR_PIXELS ];
    if ( IRGESTURE2_OK == irgesture2_read_pixels ( &irgesture2, pixels, false ) )
    {
        for ( uint8_t cnt = 0; cnt < IRGESTURE2_NUM_SENSOR_PIXELS; cnt++ )
        {
            if ( 0 == ( cnt % IRGESTURE2_SENSOR_X_SIZE ) )
            {
                log_printf( &logger, "\r\n" );
            }
            log_printf( &logger, "%d\t", pixels[ cnt ] );
        }
        log_printf( &logger, "\r\n" );
    }
}

void main ( void )
{
    application_init( );

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

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