Provide accurate heading information for map rotation and user orientation with the AK09919 and ATmega1284P
3-axis magnetometer suitable for custom pedestrian navigation systems or map heading applications
Published Jun 27, 2024
Click board™
Compass 8 Click
Dev Board
EasyAVR v7
Compiler
NECTO Studio
MCU
ATmega1284P
Transform your project into a precise digital compass ideal for applications where orientation and direction are crucial
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Hardware Overview
How does it work?
Compass 8 Click is based on the AK09919, a 3-axis electronic compass IC from AKM Semiconductor designed for precise compass applications. The AK09919 uses high-sensitivity Hall sensor technology, with a typical sensitivity of 0.15µT/LSB, to detect terrestrial magnetism across the X, Y, and Z axes. It integrates magnetic sensors, a sensor driving circuit, a signal amplifier chain, and an arithmetic circuit for signal processing. Key features of the AK09919 also include multiple operational modes, such as Power-down, single measurement, continuous measurement, and self-test. The Power-down mode conserves energy when the device is not in use, while the single measurement mode allows for precise readings on demand. The continuous measurement mode provides ongoing data for real-time applications, and the self-test mode ensures the sensor functions correctly. Additionally, the magnetic sensor overflow monitor function manages overflow conditions in the magnetic
sensors, ensuring accurate readings even in strong magnetic fields. The AK09919 also features a built-in oscillator for a stable internal clock source, maintaining consistent performance and timing accuracy. The Power On Reset circuit ensures proper initialization upon power-up, preventing erroneous readings. The self-test function, which uses an internal magnetic source, verifies the sensor's accuracy and functionality without external equipment. The built-in magnetic sensitivity adjustment circuit optimizes performance across different environments and applications. Moreover, the 16-sample FIFO data buffer allows efficient data handling, reducing the need for frequent processor intervention. This board is ideal for continuous data acquisition in map heading and pedestrian navigation systems applications. Compass 8 Click communicates with MCU using the standard I2C 2-Wire interface with a maximum clock frequency of 400kHz, fully adjustable through software registers. The AK09919 does not require a
specific Power-Up sequence but requires a voltage of 1.8V for its interface and logic part to work correctly. Therefore, a small regulating LDO, the AP2112, is used to provide a 1.8V out of mikroBUS™ power rails. This regulator can be activated via the EN pin of the mikroBUS™ socket, providing, at the same time, device enable function. Since the sensor for operation requires a power supply of 1.8V, this Click board™ also features the PCA9306 voltage-level translator, allowing the AK09919 to work with 3.3V and 5V MCU properly. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.
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.
Microcontroller Overview
MCU Card / MCU
Architecture
AVR
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
40
RAM (Bytes)
16384
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 EasyAVR v7 as your development board.
Track your results in real time
Application Output
This Click board can be interfaced and monitored in two ways:
Application Output- Use the "Application Output" window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
UART Terminal- Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.
Software Support
Library Description
This library contains API for Compass 8 Click driver.
Key functions:
compass8_get_magnetic_data- This function reads the raw magnetic sensor measurement data and calculates magnetic flux density [microTesla] using the I2C serial interface.compass8_set_operation_mode- This function sets the desired sensor operation mode by using the I2C serial interface.compass8_sw_reset- This function performs software reset by using the I2C serial interface.
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 Compass 8 Click example
*
* # Description
* This library contains API for the Compass 8 Click driver.
* The library initializes and defines the I2C drivers to
* write and read data from registers, as well as the default
* configuration for reading measurement data.
*
* The demo application is composed of two sections :
*
* ## Application Init
* The initialization of the I2C module, log UART, and additional pins.
* After the driver init, the app executes a default configuration.
*
* ## Application Task
* This example demonstrates the use of the Compass 8 Click board.
* Measures and displays magnetic flux density in microtesla (uT) for X-axis, Y-axis, and Z-axis.
* Results are being sent to the UART Terminal, where you can track their changes.
*
* @author Nenad Filipovic
*
*/
#include "board.h"
#include "log.h"
#include "compass8.h"
static compass8_t compass8;
static log_t logger;
void application_init ( void )
{
log_cfg_t log_cfg; /**< Logger config object. */
compass8_cfg_t compass8_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.
compass8_cfg_setup( &compass8_cfg );
COMPASS8_MAP_MIKROBUS( compass8_cfg, MIKROBUS_1 );
if ( I2C_MASTER_ERROR == compass8_init( &compass8, &compass8_cfg ) )
{
log_error( &logger, " Communication init." );
for ( ; ; );
}
if ( COMPASS8_ERROR == compass8_default_cfg ( &compass8 ) )
{
log_error( &logger, " Default configuration." );
for ( ; ; );
}
log_info( &logger, " Application Task " );
}
void application_task ( void )
{
compass8_axes_t axis;
if ( COMPASS8_OK == compass8_get_magnetic_data( &compass8, &axis ) )
{
log_printf( &logger, " X-axis: %.2f uT\r\n", axis.x );
log_printf( &logger, " Y-axis: %.2f uT\r\n", axis.y );
log_printf( &logger, " Z-axis: %.2f uT\r\n", axis.z );
log_printf( &logger, "--------------------\r\n" );
Delay_ms ( 100 );
}
}
int main ( void )
{
/* Do not remove this line or clock might not be set correctly. */
#ifdef PREINIT_SUPPORTED
preinit();
#endif
application_init( );
for ( ; ; )
{
application_task( );
}
return 0;
}
// ------------------------------------------------------------------------ END
