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Provide accurate motion data with BMI160 and PIC18LF4525

Precision in every move

6DOF IMU 2 Click with EasyPIC v7

Published Nov 01, 2023

Click board™

6DOF IMU 2 Click

Development board

EasyPIC v7

Compiler

NECTO Studio

MCU

PIC18LF4525

6-axis IMUs are an integral part of the development of human-machine interfaces, enhancing the way humans interact with technology

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Hardware Overview

How does it work?

6DOF IMU 2 Click is based on the BMI160, a small low-power inertial measurement unit (IMU) from Bosch Sensortec. Its highly integrated unit provides precise acceleration and angular rate (gyroscopic) measurement with low power consumption in full operation mode, allowing a great advantage in battery-driven applications. The BMI160 sensor integrates a 16-bit digital triaxial accelerometer and a 16-bit digital triaxial gyroscope, both hardware synchronized and providing high precision sensor data and accurate timing of the corresponding data with timestamps resolution of only 39μs. The acceleration range can be selected from ±2, ±4, ±8, and ±16g with sensitivity up to 17039LSB/g. The BMI160 also features an allocated FIFO buffer of 1024 bytes for handling external sensor data. This Click board™ comes with an additional header that allows BMI160 to connect an external

magnetometer over the secondary magnetometer interface (pins ASDx and ASCx), OIS interface (pins OSDO and OSCB), GND, and VCC provided out of 3V3 mikroBUS™ power rail. The BMI160 can use a geomagnetic or barometric pressure sensor from Bosch Sensortec as external sensors. The geomagnetic sensor can trigger autonomous read-out of the sensor data magnetometer without the need for intervention of the host MCU. While using an SPI interface, this sensor can be used for OIS (optical image stabilization) applications in conjunction with camera modules or advanced gaming use cases. The OIS shares the interface with the MAG-Interface (I2C). The 6DOF IMU 2 Click allows the use of both I2C and SPI interfaces, with a maximum frequency of 1MHz for I2C and 10MHz for SPI communication. The selection can be made by positioning SMD jumpers labeled COMM

SEL to an appropriate position (I2C set by default). Note that all the jumpers' positions must be on the same side, or the Click board™ may become unresponsive. There is also an I2C address selection labeled ADDR SEL and set to 0 by default. An interrupt INT pin signals to the MCU that a motion event has been sensed. This signal is selectable between two possible interrupts from BMI160, with possible selection via a marked Interrupt Selection jumper. 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.

6DOF IMU 2 Click hardware overview 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

default

Architecture

PIC

MCU Memory (KB)

48

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

3968

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
SPI Chip Select
RE0
CS
SPI Clock
RC3
SCK
SPI Data OUT
RC4
MISO
SPI Data IN
RC5
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
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Schematic

6DOF IMU 2 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 6DOF IMU 2 Click driver.

Key functions:

  • c6dofimu2_default_cfg - This function executes default configuration for 6DOF IMU 2 Click

  • c6dofimu2_read_accel - This function read Accel X-axis, Y-axis and Z-axis

  • c6dofimu2_read_gyro - This function read Gyro X-axis, Y-axis and Z-axis

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 6DofImu2 Click example
 * 
 * # Description
 * 6DOF IMU 2 Click is capable of precise acceleration and angular rate (gyroscopic) measurement.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Application Init performs Logger and Click initialization.
 * 
 * ## Application Task  
 * This is an example which demonstrates the usage of 6DOF IMU 2 Click board.
 * It measures accel and gyro coordinates (X,Y,Z) and then the results 
 * are being sent to the UART Terminal where you can track their changes for every 1 sec.
 * 
 * *note:*
 * Default communication that is set is I2C communication.
 * If you want to use SPI, you have to set up the cfg structure.
 * Also, after uploading your code on development board it needs HW Reset 
 * ( button on Board ) so the values would be properly read.
 * 
 * \author Mihajlo Djordjevic
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "c6dofimu2.h"

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

static c6dofimu2_t c6dofimu2;
static log_t logger;

c6dofimu2_accel_data_t accel_data;
c6dofimu2_gyro_data_t gyro_data;


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

void application_init ( void )
{
    log_cfg_t log_cfg;
    c6dofimu2_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.

    c6dofimu2_cfg_setup( &cfg );
    C6DOFIMU2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    c6dofimu2_init( &c6dofimu2, &cfg );
    
    log_printf( &logger, "--------------------------\r\n\n" );
    log_printf( &logger, " --- 6DOF IMU 2 Click ---\r\n" );
    log_printf( &logger, "--------------------------\r\n\n" );
    Delay_ms ( 100 );
    
    c6dofimu2_default_cfg( &c6dofimu2, &cfg );
    Delay_ms ( 100 );
    
    log_printf( &logger, " ---- Initialization ---\r\n" );
    log_printf( &logger, "--------------------------\r\n\n" );
    Delay_ms ( 100 );
}

void application_task ( void )
{
    c6dofimu2_read_accel( &c6dofimu2, &accel_data );
    Delay_ms ( 100 );
    c6dofimu2_read_gyro( &c6dofimu2, &gyro_data );
    Delay_ms ( 100 );
    
    log_printf( &logger, "    Accel    |    Gyro    \r\n" );
    log_printf( &logger, "--------------------------\r\n" );
    log_printf( &logger, " X = %d  | X = %d \r\n", accel_data.accel_x, gyro_data.gyro_x );
    log_printf( &logger, " Y = %d  | Y = %d \r\n", accel_data.accel_y, gyro_data.gyro_y );
    log_printf( &logger, " Z = %d  | Z = %d \r\n", accel_data.accel_z, gyro_data.gyro_z );
    log_printf( &logger, "--------------------------\r\n" );    
    Delay_ms ( 1000 );
}

void main ( void )
{
    application_init( );

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

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

Additional Support

Resources