WiT BWT61 User manual

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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USER MANUAL BWT61
Bluetooth 2.0 Inclinometer Sensor

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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Tutorial Link
Google Drive
Link to instructions DEMO:
WITMOTION Youtube Channel
BWT61 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

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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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 PC Connection............................................................................. - 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................................................ - 13 -
2.3 Calibration.................................................................................. - 15 -
2.3.1 Accelerometer Calibration.........................................- 16 -
2.3.2 Reset Z-axis Angle....................................................... - 17 -
2.4 Configuration.............................................................................- 18 -
2.4.1 Set Baud Rate................................................................- 18 -
2.4.2 Data Recording..............................................................- 18 -
2.4.3 Data Playback................................................................ - 20 -
2.4.4 Standby and Wake Up................................................ - 23 -
2.4.5 Placement Direction.................................................... - 23 -
2.4.6 Static Threshold............................................................ - 24 -
2.4.7 Bandwidth........................................................................- 25 -

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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3 Use Instructions with Android Phone........................................ - 27 -
3.1 APP Installation........................................................................ - 27 -
3.2 Connection................................................................................. - 29 -
3.2.1 APP Pairing...................................................................... - 29 -
3.2.2 Phone’s Bluetooth Pairing..........................................- 32 -
3.3 Calibration.................................................................................. - 34 -
3.3.1 Acceleration Calibration............................................. - 34 -
3.3.2 Reset Z-axis Angle....................................................... - 35 -
4 Multiple Connection.......................................................................... - 36 -
4.1 Download Link.......................................................................... - 36 -
4.2 Connection Instructions........................................................- 36 -
5 MCU Connection.................................................................................- 37 -
5.1 Arduino........................................................................................ - 37 -
5.2 STM32.......................................................................................... - 37 -
5.3 Raspberry pi.............................................................................. - 37 -
5.4 C#..................................................................................................- 37 -
5.5 C++.............................................................................................. - 38 -
5.6 Matlab.......................................................................................... - 38 -

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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1 Introduction
The BWT61 is a multi-sensor device detecting acceleration, angular velocity
and angle . 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.
BWT61’s scientific name is AHRS IMU sensor. A sensor measures 3-axis angle,
angular velocity, acceleration. Its strength lies in the algorithm which can
calculate three-axis angle accurately.
BWT61 is an CE standard accelerometer. It is employed where the highest
measurement accuracy is required. BWT61 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
• 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

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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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

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2 Use Instructions with PC
2.1 PC Connection
PC software is only compatible with Windows system.
BWT61 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.)

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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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.

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.1.2 USB-HID Connection
Step 1. Insert the USB-HID adapter to USB slot in the beginning
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--pairing succeeds
Step 4. Open the software, Minimu.exe
Step 5. Data will appear once the auto-search finishes.

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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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

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.2 Software Introduction
Link to download software
2.2.1 Main Menu
Main Menu of software
Button
Function
File
Launch recorded HEX file (Bin format)
Tools
Hide or display tools box on left side
Record
Record function
3D
3D Unity DEMO
Config
Configuration setting
Help
Language
Switch to English or Chinese
Bluetooth Set
Option for binding device or unbind
Firmware update
Option for firmware update
About Minimu
Info about Minimu.exe
Factory test
For manufacturer internal test only
Auto-search
Auto searching the sensor
Port
Com port selection
Baud
Baud rate selection

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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Type
Fixed setting as JY61 for BWT61
Open
Open com port
Close
Close com port
Acc Calibrate
Acceleration calibration

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.2.2 Menu of Configuration
Menu of Configuration
Button
Function
Zero Z Angle
Reset Z-axis angle to 0 degree
Acceleration Calibration
Ability to proceed accelerometer calibration
Sleep
Sleep function, not available for Bluetooth
sensor series
Baudrate
115200(100Hz) (Fixed)/ 9600(20Hz)
Mode
Serial / IIC(only for modules)
Direction
Vertical or horizontal installation
Static threshold
Static threshold for angular velocity
Bandwidth
Option for bandwidth range

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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Menu of Data
Button
Function
Time
Real time
Acceleration
Data for Acceleration
Angular Velocity
Data for Angular Velocity
Angle
Data for Angle

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.3 Calibration
Preparation:
Make sure the sensor is “Online”.
Calibration on PC software：
It is required to calibrate for the first time usage.

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.3.1 Accelerometer Calibration
Purpose:
The accelerometer calibration is used to remove the zero bias of the
accelerometer. Before calibration, there will be different degrees of bias error.
After calibration, the measurement will be accurate.
Methods:
1. Firstly keep the module horizontally stationary, then click “Acceleration
Calibration” in the “Config” of the software.
2. After 1 ~ 2 seconds, the three axial acceleration value of the module is
about 0, 0,1, the X and Y axis Angle is around 0 °. After calibration, the x-y
axis Angle is accurate.
Note: when putting the module horizontal, there is one G of gravitational
acceleration on the Z-axis.

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.3.2 Reset Z-axis Angle
Z axis to 0 is to make the initial angle of the z axis angle is relative 0 degree.
When the module is used before and z - axis drift is large, the z - axis can be
calibrated, When the module is powered on, the Z axis will automatically return
to 0.
Calibration methods as follow: firstly keep the module static, click the “Config”
open the configuration bar and then click “Reset Z-axis Angle” option, you will
see the the angle of the Z axis backs to 0 degree in the module data bar.

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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2.4 Configuration
2.4.1 Set Baud Rate
Not available for Bluetooth sensor series.
2.4.2 Data Recording
There is no memory chip in the sensor module, and the data can be recorded
and saved on the computer.
Method are as follows: Click“Record”and“Begin”will save the data as a TXT
file. The saved file is in the directory of the PC software program Data.tsv.
The beginning of the file has the value corresponding to the data.
For raw data analysis, please kindly refer to the register list shown on the
datasheet of the corresponding model.

BWT61 | manual v0707 | http://wiki.wit-motion.com/english
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It is highly recommended that data can be pasted to a Excel file. In this way, all
data will be shown in order.

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2.4.3 Data Playback
New function: When creating recorded file each time, there will a BIN file
created in the folder of record file in path of installed software meanwhile.
Recorded data playback method:
Step 1: Disconnect the sensor
Step 2: Click “File” Button and then click “Load”