Experience precise and reliable motion sensing with ADXL367 and STM32F091RC
Get ready to rumble!
Published Feb 26, 2024
Click board™
Accel 22 Click
Dev. board
Nucleo-64 with STM32F091RC MCU
Compiler
NECTO Studio
MCU
STM32F091RC
A tiny yet mighty accelerometer that's turning the world of motion sensing on its head!
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Hardware Overview
How does it work?
Accel 22 Click is based on the ADXL367, a complete 3-axis acceleration measurement system from Analog Devices that operate at low power consumption levels. It consists of an ADC for synchronous conversion of an input from a third sensor and one internal temperature sensor. It measures both dynamic accelerations, resulting from motion or shock, and static acceleration, such as tilt, and allows selectable full-scale acceleration measurements in ranges of ±2g, ±4g, and ±8g with a resolution of 0.25mg/LSB on the ±2g range. Acceleration is reported digitally, communicating via the SPI or the I2C protocol and providing 14-bit output resolution. The ADXL367 has three operating modes: Measurement mode for continuous wide-bandwidth sensing, Wake-up mode for limited bandwidth activity detection, and Standby mode for power conservation. Measurement mode represents its normal operating mode, and in this mode, acceleration data is read continuously, while the Wake-Up mode is ideal for simple detection of the presence or absence of motion at low power consumption.
Wake-up mode helps implement a motion-activated ON/OFF switch, allowing the rest of the system to Power-Down until the activity is detected. In addition, the Standby mode suspends measurement and reduces power consumption. Accel 22 Click allows using both I2C and SPI interfaces. The selection can be made by positioning SMD jumpers labeled as COMM SEL in an appropriate position. 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 ADXL367 allows choosing the least significant bit (LSB) of its I2C slave address using the SMD jumper labeled ADDR SEL. This Click board™ also possesses two register-configurated interrupt pins, I1 and I2, routed to the INT and AN pins on the mikroBUS™, which has a dual function that can trigger interrupts to alert the host of certain status conditions. They can be used as classic interrupt pins to signal MCU that an event has been sensed or can be used, e.g., I1 as an input for external clocking and I2 as input for synchronized sampling.
One or both of these alternate functions can be used concurrently; however, if an interrupt pin is used for its alternate function, it cannot simultaneously be used for its primary function, to signal interrupts. The ADXL367 incorporates a 14-bit analog-to-digital converter (ADC) to digitize the external analog signal, connected to a header at the top of the board, which is unpopulated by default. The ADC converts analog inputs ranging from 10% to 90% of the internally regulated voltage, limiting the external ADC's input range to a maximum of 1V. 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
Nucleo-64 with STM32F091RC MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
256
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
32768
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Nucleo-64 with STM32F091RC MCU as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for Accel 22 Click driver.
Key functions:
accel22_get_axesThis function reads accel X, Y, and Z axis data in mg.accel22_get_temperatureThis function reads the temperature in Celsius.accel22_get_adcThis function reads the ADC voltage.
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* @file main.c
* @brief Accel22 Click example
*
* # Description
* This example demonstrates the use of Accel 22 click board by reading and displaying
* Accel data (X, Y, and Z axis) as well as temperature and ADC measurements on the USB UART.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes the driver and performs the click default configuration.
*
* ## Application Task
* Reads and displays the Accel data (X, Y, and Z axis) as well as temperature and ADC measurements
* on the USB UART every 100ms approximately.
*
* @author Stefan Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "accel22.h"
static accel22_t accel22;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
accel22_cfg_t accel22_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.
accel22_cfg_setup( &accel22_cfg );
ACCEL22_MAP_MIKROBUS( accel22_cfg, MIKROBUS_1 );
err_t init_flag = accel22_init( &accel22, &accel22_cfg );
if ( ( I2C_MASTER_ERROR == init_flag ) || ( SPI_MASTER_ERROR == init_flag ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( ACCEL22_ERROR == accel22_default_cfg ( &accel22 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
accel22_axes_t axes;
// Wait for data ready indication
while ( !accel22_get_int1_pin ( &accel22 ) );
if ( ACCEL22_OK == accel22_get_axes ( &accel22, &axes ) )
{
log_printf( &logger, " X: %.2f mg\r\n", axes.x );
log_printf( &logger, " Y: %.2f mg\r\n", axes.y );
log_printf( &logger, " Z: %.2f mg\r\n", axes.z );
}
if ( ACCEL22_OK == accel22_enable_temperature_measurement ( &accel22 ) )
{
float temperature = 0;
// Wait for data ready indication
while ( !accel22_get_int1_pin ( &accel22 ) );
if ( ACCEL22_OK == accel22_get_temperature ( &accel22, &temperature ) )
{
log_printf( &logger, " Temperature: %.2f C\r\n", temperature );
}
}
if ( ACCEL22_OK == accel22_enable_adc_measurement ( &accel22 ) )
{
float adc_voltage = 0;
// Wait for data ready indication
while ( !accel22_get_int1_pin ( &accel22 ) );
if ( ACCEL22_OK == accel22_get_adc ( &accel22, &adc_voltage ) )
{
log_printf( &logger, " ADC: %.2f V\r\n\n", adc_voltage );
}
}
Delay_ms ( 100 );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
