FXOS8700CQ Sensor Introduction

Figure 1 FXOS8700CQ

Figure 2 FXOS8700CQ Pin Configuration

WHAT IS FXOS8700CQ?

FXOS8700CQ a small and low-powered 6-axis motion sensor single package containing 3-axis linear accelerometer and 3-axis magnetometer. There are number of practical accelerometer applications. accelerometers are used to measure static acceleration (gravity), tilt of an object, dynamic acceleration, shock to an object, velocity, orientation and the vibration of an object. FXOS8700CQ has inbuilt magnetometer which measures magnetism—the direction, strength, or relative change of a magnetic field at a particular location. Magnetometers are widely used for measuring the Earth’s magnetic field and in geophysical surveys to detect magnetic anomalies of various types. Combination of accelerometer and magnetometer provide accurate positioning information.

Table of Contents

PIN DESCRIPTION

Table 1 Pin Configuration

PIN NUMBER	SYMBOL	DESCRIPTION
1	VDDIO	Interface supply voltage
2	BYP	Internal regulator output bypass capacitor connection
3	RESERVED	Connect to GND
4	SLC/SCLK	I²C serial clock/SPI clock
5	GND	Ground
6	SDA/MOSI	I²C serial data/SPI master out, slave in
7	SA0/MISO	I²C address selection bit 0/SPI master in, slave out
8	Crst	Magnetic reset capacitor
9	INT2	Interrupt 2
10	SA1/CS_B	I²C address selection bit 1/SPI chip select (active low)
11	INT1	Interrupt 1
12	GND	Ground
13	RESERVED	Connect to GND
14	VDD	Sensor supply voltage
15	N/C	Not connected internally
16	RST	Reset input, active high. Connect to GND if unused

FEATURES

High resolution for acceleration and magnetic measurements
Complete 6-axis, e-compass hardware solution
V_DDvoltage: 1.95 V to 3.6 V
V_DDIOvoltage: 1.62 V to 3.6 V
Selectable acceleration sensor range: ±2 g/±4 g/±8 g
Magnetic sensor range: ±1200 µT
Low noise disturbance

APPLICATIONS

FIELD	APPLICATION
Security	§ Motion detection § Door opening § Smart home applications § Robotics § Unmanned aerial vehicles (UAVs) with electronic compass (e-compass) function
Medical applications	§ Patient monitoring § Fall detection § Rehabilitation
E-compass	§ Mobile devices § Tablets § Personal navigation devices
Wearable devices	§ Motion detection § Activity monitoring § Sports monitoring § Context awareness § Shock and vibration monitoring

Alternatives

LSM303D; LSM303DTR; LSM303C;

WHERE TO USE FXOS8700CQR1? | WORKING OF FXOS8700CQR1

FXOS8700CQR1 is 6-axis sensor with integrated linear accelerometer and magnetometer. Accelerometers alone used as inclinometers cannot measure rotation about the vertical axis and are affected by acceleration; magnetometers alone cannot measure rotation about the axis in the direction of the Earth’s magnetic field and can be disturbed by local magnetic fields. By combining both sensors one sensor’s weakness can be compensated by another sensor.

FXOS8700CQ has dynamically selectable acceleration full-scale ranges of ±2 g/±4 g/±8 g and a fixed magnetic measurement range of ±1200 μT. FXOS8700CQR1 can be used in any application where orientation or movement of the device is required.

Figure 3 Circuit Diagram for FX058700CQ

FX058700CQ is powered through the VDD pin. Power supply decoupling capacitors (100 nF ceramic plus 4.7 μF bulk) should be placed as close as possible to pin 14 of the FX058700CQ. The digital interface supply voltage (VDDIO) should be decoupled with a 100 nF ceramic capacitor placed as close as possible to pin 1 of the FX058700CQ. The digital control signals SCL, SDA, SA0, SA1, and RST are not tolerant of voltages exceeding VDDIO + 0.3 V. If VDDIO is removed, these pins will clamp any logic signals through their internal ESD protection diodes.

The function and timing of the two interrupt pins (INT1 and INT2) are user programmable through the I²C/SPI interface. The SDA and SCL I²C connections are open drain and therefore require a pullup resistor as shown in the application diagram in Figure 3. The INT1 and INT2 pins may also be configured for open-drain operation. If they are configured for open drain, external pullup resistors are required.

2-D VIEW AND FOOTPRINT

Figure 4 FXOS8700CQ 2-D View	Figure 5 FXOS8700CQ Footprint
*All dimentions are in millimeter

FXOS8700CQ RELATED PRODUCTS PRICE

Parts	Mfr.	Description	Stock	Prices
FXOS8700CQR1	NXP	IMU ACCEL/MAG 3-AXIS I2C/SPI QFN	2875	$1.866 Lowest
LSM303CTR	ST	IMU ACCEL/MAG I2C/SPI 12LGA	6707	$1.793 Lowest
LSM303DLHCTR	ST	IMU ACCEL/MAG 3-AXIS I2C 14LGA	31608	$1.793 Lowest
LSM303DLMTR	ST	IMU ACCEL/MAG 3-AXIS I2C 28LGA	5749	$2.738 Lowest