3D Hall 3 Click
PID: MIKROE‐3310
Weight: 23 g
3D Hall 3 click is a very accurate, magnetic field sensing Click board™, used
to measure the intensity of the magnetic field across three perpendicular
axes. It is equipped with the LIS2MDL, a low power 3D magnetic sensor.
This IC has a separate Hall sensing element on each axis, which allows a
very accurate and reliable measurement of the magnetic field intensity in a
3D space, offering a basis for accurate positional calculations. Both I2C and
SPI communication protocols are supported by the LIS2MDL. This sensor IC
features a powerful programmable interrupt engine, allowing firmware
optimization.
3D Hall 3 click is supported by a mikroSDK compliant library, which includes
functions that simplify software development. This Click board™ comes as a
fully tested product, ready to be used on a system equipped with the
mikroBUS™ socket.
Features such as the embedded self-test, support for the hard iron
compensation, selectable power mode, 16-bit data output, a wide dynamic
range of the measurement (±50 gauss), make this Click board™ a perfect
choice for various IoT applications. The internal non-volatile memory
contains the calibration parameters, making the 3D Hall 3 click a very
accurate magnetic sensor, perfectly suited for the development of various
position sensing applications, contactless knobs, encoders, switches,
potentiometers, or some other type of magnetic field sensing applications
based on the accurate spatial sensing.
How does it work?
3D Hall 3 click carries the LIS2MDL, a low power 3D magnetic sensor,
from STMicroelectronics. This sensor relies on a Hall effect to accurately sense
magnetic field changes on three perpendicular axes. The internal magnetic
field sensing elements are multiplexed and connected to a 16bit low noise
Analog to Digital Converter (ADC), which sequentially samples each sensor,
providing 16-bit spatial data over the digital interface. An additional thermal
sensor is also available, and it is used for thermal compensation.
The magnetic sensor has a very low pin count. Therefore, SPI and I2C lines
are multiplexed on the same pins. In addition, the SPI data in (SDI) and SPI
data out (SDO) share the same pin. In order to allow functionality for both
SPI READ and SPI WRITE functions, 3D Hall 3 click incorporates another IC:
the 74HC4053, a triple 2-channel multiplexer/demultiplexer IC from NXP is
used in conjunction with the RST pin of the mikroBUS™, labeled as CSS. This
allows to demultiplex the SDI/SDO pin of the LIS2MDL and route the two
resulting pins to appropriate pins of the mikroBUS™ (SDI and SDO).
The rest of the communication interface selection procedure relies on
switching the appropriate SMD jumpers, grouped under the I2C/SPI label.
Note that all the I2C/SPI group jumpers need to be switched at the same
side: all three should either be soldered as I2C or SPI. If one of them shows
in the opposite position from the rest, the communication with the IC might
not be possible.
The power consumption is a big concern as of lately, with the introduction of
the IoT. The ability to work in a low power mode is a must for every device
which is to be used for any type of IoT networking. The LIS2MDL magnetic
sensor features two operational modes, with the addition of a low-pass filter
(LPF). The power consumption is in a close relationship with the data output
refresh rate (ODR). When operated in Low Power mode, and with the LPF
and the offset cancelation turned OFF, the power consumption of the sensor
alone drops down to 25 μA. Turning on the LPF and the offset cancelation
will double the power consumption for the same ODR frequency to 50 μA,
which is still in a domain of micropower consumption. However, filtering and
offset cancelation options offer less noise and more accurate readings for
both high-resolution and low-resolution modes.
The LIS2MDL magnetic sensor also features a powerful programmable
interrupt engine, which allows many event sources to be signaled via the
interrupt pin (INT/DRDY), which is routed from the sensor to the mikroBUS™
INT pin. A very useful function of the interrupt engine is the signaling of the
data ready event. That way, the host MCU does not have to poll the sensor
for the data acquisition. The sensor can simply trigger an interrupt when the
data is ready for reading. The interrupt engine allows some other
customizations of the interrupt signal, such as the polarity, pulse/latch
mode, and so on.
The sensor provides raw data output, based on a strength of the magnetic
field. The measurement is affected by many factors: slight manufacturing
differences between ICs affect the readings, even the slight differences
between Hall plates within the same IC might affect the accuracy, although
the IC contains highly matched sensing elements. Also, the altitude might
affect the readings, as well as temperature changes. Therefore, the sensor
IC is equipped with the thermal sensor, used to measure the influence of the
ambient temperature. Unlike errors which occur due to the influence of other
parameters, the influence of the temperature is not linear, so a proper
firmware development approach by using LUT tables is highly advisable.
The power mode, output data rate, interrupt thresholds for each axis, and
other working parameters, including the availability of the I2C interface, are
contained within the configuration registers of the LIS2MDL magnetic sensor.
The sensor is highly configurable, with many configuration options. The
LIS2MDL datasheet contains an in-depth explanation of all the registers and
their functionality. However, 3D Hall 3 software library contains simplified
functions that allow straight-forward readings to be performed, reducing the
steps needed for a proper initialization and configuration of the device.
The Click board™ can operate with 3.3V MCUs only, it is set to work over the
I2C by default, and it is already equipped with the pull-up resistors. It is
ready to be used as soon as it is inserted into a mikroBUS™ socket of the
development system.
Specifications
Type
Hall effect,Magnetic
Applications
It is well-suited for development of various position
sensing applications, contactless knobs, encoders,
switches and potentiometers, or some other type of
magnetic field measuring application, based on an
accurate spatial sensing.
On-board
modules
LIS2MDL, a low power 3D magnetic sensor, by
STMicroelectronics; 74HC4053, a triple 2-channel
multiplexer/demultiplexer IC from NXP.
Key Features
Three independent Hall sensor channels allow high
accuracy, additional thermal sensor for compensation,
small package case allows very compact desing still
offering a lot of features, programmable interrupt engine,
low power consumption, and more.
Interface
I2C,SPI
Input
Voltage
3.3V
Click board
size
M (42.9 x 25.4 mm)
Pinout diagram
This table shows how the pinout on 3D Hall 3 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
SDI/SDO
Selection
CCS
2
RST
INT
15
INT
SPI Chip Select
CS
3
CS
RX
14
NC
SPI Clock
SCK
4
SCK
TX
13
NC
SPI SDO
SDO
5
MISO
SCL
12
SCL
I2C Clock/INT
SPI Data IN
SDI
6
MOSI
SDA
11
SDA
I2C
Data/ADDR
+3.3V
7
3.3V
5V
10
NC
GND
8
GND
GND
9
GND
Power supply
Ground
Onboard settings and indicators
Label
LD1
Name
Default
PWR
-
Description
Power LED indicator
Interrupt
Ground
JP1JP3
I2C/SPI
Left
Communication interface selection: left
position I2C, right position SPI
Software support
We provide a library for the 3D Hall 3 click on our LibStock page, as well as a
demo application (example), developed using MikroElektronika compilers. The demo can
run on all the main MikroElektronika development boards.
Library Description
The library initializes and defines the I2C bus or SPI bus driver and drivers
that offer a choice for writing data in registers and reading data from
registers. The library includes function for read X/Y/Z axis data, set offset,
read interrupt state. The user also has the function for configuration chip.
Key functions:
void c3dhall3_readXYZ( int16_t *OUT_XYZ ) - Reading X Y Z - axes values
void c3dhall3_configuration( void ) - Click default configuration
void c3dhall3_writeOffset(uint8_t axis, uint16_t offset ) - Writing X Y or Z-axis offset
Examples description
The application is composed of the three sections :
System Initialization - Initializes I2C communication, INT pin as input, RST pin as output and CS
pin as output
Application Initialization - Initializes I2C driver and 3D Hall 3 to basic settings
Application Task - Reads and logs XYZ axes values
void applicationTask( )
{
c3dhall3_readXYZ( &axes_xyz[0] );
mikrobus_logWrite( " X:", _LOG_TEXT );
IntToStr( axes_xyz[0], text );
mikrobus_logWrite( text, _LOG_TEXT );
mikrobus_logWrite( " Y:", _LOG_TEXT );
IntToStr( axes_xyz[1], text );
mikrobus_logWrite( text, _LOG_TEXT );
mikrobus_logWrite( " Z:", _LOG_TEXT );
IntToStr( axes_xyz[2], text );
mikrobus_logWrite( text, _LOG_LINE );
Delay_ms(100);
}
The full application code, and ready to use projects can be found on
our LibStock page.
Other mikroE Libraries used in the example:
I2C
SPI
UART
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.
https://www.mikroe.com/3d‐hall‐3‐click/2‐20‐19