Magneto 5 click
PID: MIKROE‐3050
Weight: 24 g
Magneto 5 click is a very accurate and reliable magnetic sensor device, which features
the MEMSIC MMC34160PJ, a 3-axis magnetic sensor IC. MMC34160PJ IC features an
onboard signal processing and I2C communication, simplifying the application
development and reducing the host MCU load. It is a very accurate sensor, which can
sense the heading direction with the precision of ±1˚, with the full-scale magnetic field
detection of ±16 G. The device also has a RESET function, which eliminates
measurement offset errors and restores the internal magnetic field orientation.
Featuring onboard signal processing, fast I2C communication, RESET function which
restores the sensor accuracy, low power consumption, and high precision with the low
noise, this Click board™ is an ideal solution for developing portable electronic compass
applications, but it is not limited only to directional measurement. It can be also used for
the detection of a magnetic field, vehicle detection, and similar applications that rely on
an accurate magnetic field sensing in all three axes.
How does it work?
This Click board™ uses the MMC34160PJ, a 3-axis magnetic sensor IC from MEMSIC Inc.
This integrated anisotropic magneto-resistive (AMR) sensor consists of permalloy film,
deposited on a silicon wafer. One of the important characteristics of the permalloy (a
nickel-iron alloy) is that it can be easily magnetized and demagnetized under the
influence of the magnetic field. A strong field is applied during the manufacture, so that
the permalloy film becomes magnetized, with the magnetic vector established in a
specific direction. When the sensor is affected by an external magnetic field applied
perpendicularly to the existing magnetic vector, it will rotate this vector and change its
orientation. This will result in a change of the resistance of the permalloy, which varies
with the intensity of the applied field. The MEMSIC AMR sensor is incorporated into a
Wheatstone bridge configuration to maximize Signal to Noise ratio. This way, the
influence of the external field can be measured.
The resulting characteristics of this sensor IC, are impressive: it can sense the heading
direction with the accuracy of ±1˚, it has a high SNR with only 1.5 mG of total RMS
noise, a resolution of ±0.5 mG when using 16 bit ADC mode, and ±16 G full-scale
reading.
There are two internal configuration registers, used to set up the device and its working
parameters. They allow the sampling resolution to be set (12bit, 14bit, or 16bit),
sampling mode (continuous or single shot), the sampling frequency when working in
continuous mode, and more. Among other options, these control registers offer a way
to trigger SET and RESET event. Before SET or RESET pulses are triggered, an external
capacitor connected to the CAP pin has to be recharged. This is also done by setting an
appropriate bit in the control register.
The Status register offers the status indication for various events. It signalizes whether
the integrated charge pump completed external capacitor recharging process, or if the
reading of the internal register was successful, if the measurement was completed
successfully, and it indicates the result of the self-test command.
The complete description of the internal registers can be found in the datasheet of the
MMC34160PJ sensor IC. However, the included software library offers functions that
simplify working with this device, taking care of the proper order of actions that needs
to be followed, before reading the X, Y and Z position from the appropriate output
registers. It also simplifies the reading process itself, providing the measurement values,
directly.
To overcome situations where the external field might be too strong (more than 25 G)
and disturb the internal magnetic vector of the permalloy film, a SET/RESET function is
employed to restore the magnetic vector, by applying a high current pulse to an internal
magnetically coupled strap.
The MMC34160PJ uses I2C communication, with the appropriate pins routed to the
mikroBUS™. This ensures a reliable operation of the device. In addition, this device uses
an SMD jumper, used to select the logic voltage level, allowing interfacing to both 3.3V
and 5V MCUs. Two level shifting MOSFETs are used on I2C lines to allow both 3.3V and
5V operation since the sensor IC itself is not 5V tolerant.
Specifications
Type
Magnetometer
It is an ideal solution for developing portable electronic compass
Applications
applications, but it can be also used for the detection of a magnetic field,
vehicle detection, and similar applications that rely on an accurate magnetic
field sensing in all three axes.
Key Features
Accurate sensing of the magnetic field in all three axes, SET and RESET
functions for the internal magnetic field restoration, on-chip processing
functions, can be interfaced with the wide range of both 3.3V and 5V MCUs
Interface
Input
Voltage
Click board
size
I2C
3.3V,5V
M (42.9 x 25.4 mm)
Pinout diagram
This table shows how the pinout on Magneto 5 click corresponds to the pinout on the
mikroBUS™ socket (the latter shown in the two middle columns).
Notes
Pin
Pin
Notes
NC
1
AN
PWM
16
NC
NC
2
RST
INT
15
NC
NC
3
CS
RX
14
NC
NC
4
SCK
TX
13
NC
NC
5
MISO
SCL
12
SCL
I2C Clock
NC
6
MOSI
SDA
11
SDA
I2C Data
+3V3
7
3.3V
5V
10
+5V
Power Supply
Power Supply
Ground
GND
8
GND
GND
9
GND
Ground
Onboard settings and indicators
Label
Name
Default
LD1
PWR
-
JP1
3V3, 5V
Left
Description
Power LED indicator
Logic voltage level selection: left position 3.3V, right
position 5V
Magneto 5 click electrical specifications
Description
Min
Typ
Max
Unit
Magnetic field measurement range on each axis
-16
-
16
G
External disturbing field intensity
-25
-
25
G
Heading accuracy
-1
-
1
Deg (˚)
Software support
We provide a library for Magneto 5 click on our Libstock page, as well as a demo
application (example), developed using MikroElektronika compilers and mikroSDK. The
provided click library is mikroSDK standard compliant. The demo application can run on
all the main MikroElektronika development boards.
Library Description
This library provides generic functions for working with the Click board™.
Key functions:
void magneto5_reset( void ); - Used to software reset the sensor.
float magneto5_getAxisValue(uint8_t axis, uint8_t maxResolution); - The function returns
void magneto5_getAxisData( int16_t *axisBuffer, uint8_t maxResolution ); - Used for the
the calculated Gauss value.
reading of the raw axis data from registers.
Examples Description
The application is composed of three sections:
System Initialization - Initializes I2C module
Application Initialization - Initializes driver init and set measurement mode and channel
Application Task - (code snippet) - Reads X / Y / Z data axis and logs to USBUART every 1 sec.
void applicationTask()
{
X_axis = magneto5_getAxisValue( _MAGNETO5_AXIS_X, _MAGNETO5_CH3_12bits_1ms);
Y_axis = magneto5_getAxisValue( _MAGNETO5_AXIS_Y, _MAGNETO5_CH3_12bits_1ms );
Z_axis = magneto5_getAxisValue( _MAGNETO5_AXIS_Z, _MAGNETO5_CH3_12bits_1ms );
FloatToStr( X_axis, writeText );
mikrobus_logWrite( "‐‐ X axis : ", _LOG_TEXT );
mikrobus_logWrite( writeText, _LOG_LINE );
FloatToStr( Y_axis, writeText );
mikrobus_logWrite( "‐‐ Y axis : ", _LOG_TEXT );
mikrobus_logWrite( writeText, _LOG_LINE );
FloatToStr( Z_axis, writeText );
mikrobus_logWrite( "‐‐ Z axis : ", _LOG_TEXT );
mikrobus_logWrite( writeText, _LOG_LINE );
mikrobus_logWrite( " ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐ ", _LOG_LINE );
Delay_ms( 1000 );
}
The full application code, and ready to use projects can be found on our Libstock page.
Other mikroE Libraries used in the example:
Conversions
I2C
UART
C_String Library
Additional notes and information
Depending on the development board you are using, you may need USB UART
click, USB UART 2 click or RS232 click to connect to your PC, for development systems
with no UART to USB interface available on the board. The terminal available in all
MikroElektronika compilers, or any other terminal application of your choice, can be
used to read the message.
mikroSDK
This click board is supported by mikroSDK - MikroElektronika Software Development Kit.
To ensure proper operation of mikroSDK compliant click board demo applications,
mikroSDK should be downloaded from the LibStock and installed for the compiler you
are using.
For more information about mikroSDK, visit the official page.
https://www.mikroe.com/magneto‐5‐click?search_query=MIKROE‐3050&results=1 7‐11‐18
