Intermediate
30 min

Capture, analyze, and optimize movement with ADXL314 and ATmega324P like never before

Unraveling motion's secrets in every direction

Accel 29 Click with EasyAVR v7

Published Sep 13, 2023

Click board™

Accel 29 Click

Dev Board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega324P

Elevate your projects and enhance connectivity with our 3D accelerometer, ushering in an era of improved data accuracy and responsiveness

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Hardware Overview

How does it work?

Accel 29 Click is based on the ADXL314, a complete three-axis ±200g acceleration measurement system from Analog Devices, operating at low power levels. The ADXL314 measures both dynamic accelerations resulting from motion or shock and static accelerations, such as gravity. It provides digital output data formatted as 16-bit, with acceleration reported digitally through a configurable and selectable serial interface. The ADXL314 automatically modulates its power consumption proportionately to its output data rate. If additional power savings are desired, it also offers lower power modes, enabling intelligent motion-based power management with threshold sensing and active acceleration measurement at low power dissipation. The ADXL314 is based on a polysilicon surface-micromachined structure built on top of a silicon wafer that suspends the

structure over the surface of the wafer, providing resistance against forces due to applied acceleration. Deflection of the structure is measured using differential capacitors that consist of independent fixed plates and plates attached to the moving mass. Acceleration deflects the proof mass and unbalances the differential capacitor, producing a sensor output whose amplitude is proportional to acceleration. Phase-sensitive demodulation is used to determine the magnitude and polarity of the acceleration. As mentioned, the acceleration data is accessed through the I2C or SPI interface with a maximum frequency of 400kHz for I2C and 5MHz for SPI communication. The selection is made by positioning SMD jumpers labeled COMM SEL appropriately. Note that all the jumpers' positions must be on the same side, or the Click board™

may become unresponsive. While the I2C interface is selected, the ADXL314 allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labeled ADDR SEL. This board also possesses two interrupts, IT1 and IT2, routed to, where, by default, the AN and IT pins stand on the mikroBUS™ socket, entirely programmed by the user through a serial interface. They signal MCU that a motion event has been sensed. 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.

Accel 29 Click top side image
Accel 29 Click bottom side image

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. 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, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR 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 a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V 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 which cover a wide range of 16-bit AVR MCUs. EasyAVR 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.

EasyAVR v7 horizontal image

Microcontroller Overview

MCU Card / MCU

ATmega324P

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

2048

Used MCU Pins

mikroBUS™ mapper

Interrupt 1
PA7
AN
NC
NC
RST
SPI Chip Select
PA5
CS
SPI Clock
PB7
SCK
SPI Data OUT
PB6
MISO
SPI Data IN
PB5
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
Interrupt 2
PD2
INT
NC
NC
TX
NC
NC
RX
I2C Clock
PC0
SCL
I2C Data
PC1
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

Accel 29 Click Schematic schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

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

EasyAVR v7 front image hardware assembly
Buck 22 Click front image hardware assembly
MCU DIP 40 hardware assembly
EasyAVR 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

1. Once the code example is loaded, pressing the "FLASH" button initiates the build process, and programs it on the created setup.

2. After the programming is completed, click on the Tools icon in the upper-right panel, and select the UART Terminal.

3. After opening the UART Terminal tab, first check the baud rate setting in the Options menu (default is 115200). If this parameter is correct, activate the terminal by clicking the "CONNECT" button.

4. Now terminal status changes from Disconnected to Connected in green, and the data is displayed in the Received data field.

UART_Application_Output

Software Support

Library Description

This library contains API for Accel 29 Click driver.

Key functions:

  • accel29_calibrate_offset - This function calibrates accel offset to the specified values by setting the OFSX/Y/Z registers

  • accel29_get_avg_axes - This function reads a specified number of samples for accel X, Y, and Z axis data in g and averages them

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 Accel 29 Click example
 *
 * # Description
 * This example demonstrates the use of Accel 29 click board by reading and
 * displaying the accelerometer data (X, Y, and Z axis) averaged from 100 samples.
 *
 * The demo application is composed of two sections :
 *
 * ## Application Init
 * Initializes the driver, performs the click default configuration, and calibrates
 * the accel data offsets.
 *
 * ## Application Task
 * Reads and displays on the USB UART the accelerometer data (X, Y, and Z axis)
 * averaged from 100 samples.
 *
 * @note
 * This click board should be used for high g applications of up to +-200g. 
 * It is not recommended for low g applications because of its high scale
 * factor which is about 48.83 mg per LSB.
 *
 * @author Stefan Filipovic
 *
 */

#include "board.h"
#include "log.h"
#include "accel29.h"

/**
 * Starting accel position, used for calibrating accel offset. 
 * Should be in a range from -24.96 to 24.765 g.
 * Offset calibrating scale factor is 0.195 g per LSB.
 */
#define ACCEL29_CALIB_X     0.0f
#define ACCEL29_CALIB_Y     0.0f
#define ACCEL29_CALIB_Z     1.0f

static accel29_t accel29;
static log_t logger;

void application_init ( void )
{
    log_cfg_t log_cfg;  /**< Logger config object. */
    accel29_cfg_t accel29_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.
    accel29_cfg_setup( &accel29_cfg );
    ACCEL29_MAP_MIKROBUS( accel29_cfg, MIKROBUS_1 );
    err_t init_flag = accel29_init( &accel29, &accel29_cfg );
    if ( ( I2C_MASTER_ERROR == init_flag ) || ( SPI_MASTER_ERROR == init_flag ) )
    {
        log_error( &logger, " Communication init." );
        for ( ; ; );
    }
    
    if ( ACCEL29_ERROR == accel29_default_cfg ( &accel29 ) )
    {
        log_error( &logger, " Default configuration." );
        for ( ; ; );
    }
    
    accel29_axes_t calib_axes;
    calib_axes.x = ACCEL29_CALIB_X;
    calib_axes.y = ACCEL29_CALIB_Y;
    calib_axes.z = ACCEL29_CALIB_Z;
    if ( ACCEL29_ERROR == accel29_calibrate_offset ( &accel29, calib_axes ) )
    {
        log_error( &logger, " Calibrate offset." );
        for ( ; ; );
    }
    
    log_info( &logger, " Application Task " );
}

void application_task ( void )
{
    accel29_axes_t axes;
    if ( ACCEL29_OK == accel29_get_avg_axes ( &accel29, ACCEL29_NUM_OF_SAMPLES, &axes ) )
    {
        log_printf( &logger, " X: %.1f g\r\n", axes.x );
        log_printf( &logger, " Y: %.1f g\r\n", axes.y );
        log_printf( &logger, " Z: %.1f g\r\n\n", axes.z );
    }
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources

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