Intermediate
30 min
0

Create immersive augmented reality experiences with ADPS9930 and PIC18F45K42

Navigating the world with proximity awareness

Proximity 7 Click with EasyPIC v8

Published Oct 14, 2023

Click board™

Proximity 7 Click

Development board

EasyPIC v8

Compiler

NECTO Studio

MCU

PIC18F45K42

Join us on a journey to discover how proximity detection is changing the way we perceive and interact with our surroundings

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Hardware Overview

How does it work?

Proximity 7 Click is the ADPS9930, a digital ambient and proximity sensor from Broadcom. It is an accurate and reliable proximity and ambient light sensor, aimed towards the power saving in applications that use TFT or LCD panels. By offering a huge dynamic range, the ADPS9930 sensor allows to be placed behind a dark glass or a semi-transparent screen bezel, but also to be exposed to a bright sunlight. A proprietary design of the integrated constant-current LED driver enables plug and play proximity detection up to 100mm, eliminating the need for a calibration procedure. By integrating micro-optics elements within the casing, ADPS9930 greatly simplifies the application design. Proximity of an object is detected using an IR LED, which emits pulses of light towards the object. The amount of the reflected IR light is measured by an integrated IR photodiode on channel 1. During LED ON time, the amount of the reflected IR light is measured and integrated. The background IR light is also measured and integrated, during LED OFF time. It is then subtracted from the final result, allowing for an accurate measurement with the reduced amount of the background IR noise. After it has

been scaled to a 16-bit value, the final result is available on the output registers, in the LOW/HIGH byte format. Commonly, photosensitive elements are most sensitive to IR light. A human eye does cannot detect IR light. Therefore, the PD element has to filter out IR light so that only the visible part of the light is allowed through. The channel0 is equipped with such PD, making it usable for the ALS sensing. During the ALS measurement, both channels are measured. The datasheet of the ADPS9930 offers a conversion formula that can be used to obtain results in physical units (lx). These formulas also take the IR measurement from the channel 1 into the consideration, completely reducing its influence on the final result. By adjusting the integration time (also known as oversampling), the flickering effect of a fluorescent light can be completely eliminated. The extensive interrupt engine allows an optimized firmware to be written. Four registers are used to specify the low and the high threshold for the ALS and proximity measurements. Whenever these thresholds are exceeded, an interrupt status bit will be set in the respective register. The user has the ability to assign an external pin to an interrupt,

so the MCU can be alerted whenever an interrupt event occurs. The interrupt is generated whenever the threshold value is exceeded for a programmed number of times (interrupt persistence). This is useful to prevent false and erratic interrupt reporting. The power consumption is mainly affected by the integration time. It is a mean value of a programmable number of consecutive measurements, which is performed in order to reduce the noise, and improve the sensitivity, resolution, etc. However, it has an adverse impact on the overall power consumption, as the time frame during which the device is active, is extended: more measurements, longer activity. The internal state machine puts the ADPS9930 in a standby mode between readings, thus reducing the overall power consumption. Proximity 7 click uses an I2C interface to communicate with the host MCU. It is equipped with a SMD jumper labeled as VCC SEL. This jumper is used to select the power supply for the pull-up resistors on the I2C bus, allowing both 3.3V and 5V MCUs to be interfaced with this Click board™.

Proximity 7 Click top side image
Proximity 7 Click bottom side image

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.

EasyPIC v8 horizontal image

Microcontroller Overview

MCU Card / MCU

PIC18F45K42

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

Proximity 7 Click Schematic 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.

EasyPIC v8 front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyPIC v8 DIP 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
Necto image step 8 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 Proximity 7 Click driver.

Key functions:

  • proximity7_get_proximity_data - Get proximity data

  • proximity7_get_lux_level - Get lux level

  • proximity7_set_proximity_offset - Set proximity offset

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 Proximity7 Click example
 * 
 * # Description
 * This application give us lux level and proximiti data.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes I2C driver and writes basic settings to device registers
 * 
 * ## Application Task  
 * Logs lux level and proximity data
 * 
 * *note:* 
 * - When setting LED drive strength please note that if "proximity drive level - PDL" bit in "configuration register" is set to 1, LED drive current values are reduced by 9.
 * - When setting wait time note that if "wait long - WLONG" bit is set to 1, time is 12x longer. Therefore if WLONG == 1 set time between 33ms and 8386.56ms.
 * - When setting ALS gain note that if "ALS gain level - AGL" bit is set to 1, ALS gains are scaled by 0.16, otherwise, they are scaled by 1.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "proximity7.h"

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


static proximity7_t proximity7;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;
    proximity7_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.

    proximity7_cfg_setup( &cfg );
    PROXIMITY7_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    proximity7_init( &proximity7, &cfg );

    Delay_ms( 100 );

    proximity7_default_cfg( &proximity7 );

    log_printf( &logger, "> > > Default configuration done < < <\r\n" );
}

void application_task ( void )
{
    uint8_t write_buffer[ 2 ];
    uint8_t read_buffer[ 1 ] ;
    float lux_level;
    uint16_t proximity;
    uint8_t als_valid;
    uint8_t proximity_valid;

    proximity7_generic_read( &proximity7, PROXIMITY7_STATUS | PROXIMITY7_REPEATED_BYTE, &read_buffer[ 0 ], 1 );
    
    als_valid = read_buffer[ 0 ] & PROXIMITY7_ALS_VALID_MASK;
    proximity_valid = read_buffer[ 0 ] & PROXIMITY7_PROXIMITY_VALID_MASK;
    
    if ( ( als_valid != 0 ) && ( proximity_valid != 0 ) )
    {
        log_printf( &logger, " " );

        lux_level = proximity7_get_lux_level( &proximity7 );
        log_printf( &logger, "> > > Lux level   : %f lx\r\n", lux_level );
    
        proximity = proximity7_get_proximity_data( &proximity7 );
        log_printf( &logger, "> > > Proximity   : %d\r\n", proximity );

        write_buffer[ 0 ] = PROXIMITY7_SPECIAL_FUNCTION | PROXIMITY7_PROXIMITY_AND_ALS_INT_PIN_CLEAR;
        proximity7_generic_write( &proximity7, PROXIMITY7_SPECIAL_FUNCTION | PROXIMITY7_PROXIMITY_AND_ALS_INT_PIN_CLEAR, &write_buffer[ 0 ], 1 );
    }
    
    Delay_ms( 300 );
}

void main ( void )
{
    application_init( );

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


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

Additional Support

Resources