WiT BWT901 User manual

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 1 -
USER MANUAL BWT901
Bluetooth 2.0 Inclinometer Sensor

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 2 -
Tutorial Link
Google Drive
Link to instructions DEMO:
WITMOTION Youtube Channel
BWT901 Playlist
If you have technical problems or cannot find the information that you need in the
provided documents, please contact our support team. Our engineering team is
committed to providing the required support necessary to ensure that you are
successful with the operation of our AHRS sensors.
Contact
Technical Support Contact Info
Application
● AGV Truck
● Platform Stability
● Auto Safety System
● 3D Virtual Reality
● Industrial Control
● Robot
● Car Navigation
● UAV
● Truck-mounted Satellite Antenna Equipment

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 3 -
Contents
Tutorial Link................................................................................................................... - 2 -
Contact............................................................................................................................ - 2 -
Application......................................................................................................................- 2 -
Contents..........................................................................................................................- 3 -
1 Introduction............................................................................................................... - 5 -
1.1 Warning Statement......................................................................................- 6 -
1.2 LED Status.......................................................................................................- 6 -
2 Use Instructions with PC...................................................................................... - 7 -
2.1 Connection Method...................................................................................... - 7 -
2.1.1 Serial Connection............................................................................. - 7 -
2.1.2 USB-HID Connection.......................................................................- 9 -
2.1.3 PC’s Bluetooth Connection......................................................... - 10 -
2.2 Software Introduction.............................................................................. - 11 -
2.2.1 Main Menu.........................................................................................- 11 -
2.2.2 Menu of Configuration..................................................................- 12 -
2.3 Calibration.....................................................................................................- 16 -
2.3.1 Accelerometer Calibration.......................................................... - 16 -
2.3.2 Magnetic Field Calibration.......................................................... - 18 -
2.3.3 Gyroscope Automatic Calibration............................................ - 21 -
2.3.4 Reset Z-axis Angle........................................................................ - 21 -
2.3.5 Reset Height to 0........................................................................... - 21 -
2.4 Configuration............................................................................................... - 22 -
2.4.1 Return Content............................................................................... - 22 -
2.4.2 Output Rate......................................................................................- 23 -
2.4.3 Baud Rate..........................................................................................- 23 -
2.4.4 Data Recording............................................................................... - 24 -

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 4 -
2.4.5 Data Playback..................................................................................- 26 -
2.4.6 Standby and Wake Up................................................................. - 28 -
2.4.7 Placement Direction......................................................................- 28 -
2.4.8 Bandwidth......................................................................................... - 29 -
2.4.9 6-axis/ 9-axis Algorithm............................................................. - 31 -
3 Use Instructions with Android Phone............................................................- 32 -
3.1 APP Installation...........................................................................................- 32 -
3.2 Connection....................................................................................................- 33 -
3.2.1 APP Pairing........................................................................................- 33 -
3.2.2 Phone’s Bluetooth Pairing...........................................................- 35 -
3.3 Calibration.....................................................................................................- 37 -
3.3.1 Acceleration Calibration...............................................................- 37 -
3.3.2 Magnetic Field Calibration.......................................................... - 38 -
4 Multiple Connection..............................................................................................- 39 -
4.1 Download Link.............................................................................................- 39 -
4.2 Connection Instructions.......................................................................... - 39 -
5 MCU Connection.................................................................................................... - 40 -
5.1 Arduino...........................................................................................................- 40 -
5.2 STM32.............................................................................................................- 40 -
5.3 Raspberry pi.................................................................................................- 40 -
5.4 C#.................................................................................................................... - 40 -
5.5 C++................................................................................................................. - 41 -
5.6 Matlab............................................................................................................. - 41 -

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 5 -
1 Introduction
The BWT901 is a multi-sensor device detecting acceleration, angular velocity,
angle as well as magnetic filed. The small outline makes it perfectly suitable
for industrial retrofit applications such as condition monitoring and predictive
maintenance. Configuring the device enables the customer to address a
broad variety of use cases by interpreting the sensor data by smart
algorithms.
BWT901’s scientific name is AHRS IMU sensor. A sensor measures 3-axis
angle, angular velocity, acceleration, magnetic field. Its strength lies in the
algorithm which can calculate three-axis angle accurately.
BWT901 is an CE standard accelerometer. It is employed where the highest
measurement accuracy is required. BWT901 offers several advantages over
competing sensor:
• Heated for best data availability: new WITMOTION patented zero-bias
automatic detection calibration algorithm outperforms traditional
accelerometer sensor
• High precision Roll Pitch Yaw (X Y Z axis) Acceleration + Angular Velocity +
Angle + Magnetic Field output
• Low cost of ownership: remote diagnostics and lifetime technical support by
WITMOTION service team
• Developed tutorial: providing manual, datasheet, Demo video, free software
for Windows computer, APP for Android smartphones , and sample code for
MCU integration including 51 serial, STM32, Arduino, Matlab, Raspberry Pi,
communication protocol for project development
• WITMOTION sensors have been praised by thousands of engineers as a
recommended attitude measurement solution

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 6 -
1.1 Warning Statement
Putting more than 5 Volt across the sensor wiring of
the main power supply can lead to permanent damage
to the sensor.
VCC cannot connect with GND directly, otherwise it
will lead to the burning of the circuit board.
For proper instrument grounding: use WITMOTION
with its original factory-made cable or accessories.
Do not change the baud rate because
WITMOTION BLUETOOTH sensor’s baud rate is
fixed.
For secondary developing project or integration:
use WITMOTION with its compiled sample code
1.2 LED Status
LED
Status
Remark
Red
Flashing
Working
Blue
Flashing
Pairing process
Keeping still
Successful pairing

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 7 -
2 Use Instructions with PC
2.1 Connection Method
PC software is only compatible with Windows system.
BWT901 Playlist
2.1.1 Serial Connection
Step 1. Connect the sensor with a serial converter
PIN Connection:
VCC - 5V
TX - RX
RX - TX
GND - GND
(When connecting with computer, VCC-5V is recommended.)

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 8 -
Recommended tools:
3-in-1 converter 6-in-1 converter TTL serial cable
Step 2. Unzip the software and install the driver CH340 or CP2102
(Depending on which accessory for usage.)
Link to tutorial of 3-in-1 serial converter/ TTL serial cable (CH340 driver)
Link to tutorial of 6-in-1 serial converter (CP2102 driver)
Step 3. Plugin the converter to computer and confirm the “com port” in device
manager
Step 4. Open the software(Minimu.exe)
Data will appear after auto-search finishes
Notice: If not successful, please operate manually
Choose the com port and baud rate 115200, data will be shown on the software.

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 9 -
2.1.2 USB-HID Connection
Step 1. Plugin the USB-HID adapter to computer
Step 2. Power on the sensor after red light of HID adapter flashes
Step 3. Wait till the sensor's blue LED light keeps on--means pairing succeeded
Step 4. Open the software, Minimu.exe
Step 5. Data will appear once the auto-search finishes

BWT901 | manual v0707 | http://wiki.wit-motion.com/english
- 10 -
2.1.3 PC’s Bluetooth Connection
Step 1. Turn on computer's Bluetooth
Step 2. Power on the sensor
Step 3. Search HC-06 device and input pairing password, 1234
Step 4. Confirm the “outgoing com port” on “More Bluetooth Options” page
Step 5. Open software (Minimu.exe) and choose the correct com port
Step 6. Data will appear once the automatic search finishes