USER MANUAL WT901SDCL Inclinometer Sensor Acceleration Data Logger WT901SDCL | manual v0707 | http://wiki.wit-motion.
Tutorial link Google Drive Link to instructions DEMO: WITMOTION Youtube Channel WT901SDCL 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.
Contents Tutorial link.................................................................................................................... - 2 Contact............................................................................................................................ - 2 Application...................................................................................................................... - 2 Contents...........................................................................................
2.4.7 File Conversion................................................................................- 31 2.4.8 Placement Direction...................................................................... - 34 2.4.9 Bandwidth......................................................................................... - 35 2.4.10 Restore Factory Setting............................................................ - 37 2.4.11 6-axis/ 9-axis Algorithm...........................................................
1 Introduction The WT901SDCL 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. WT901SDCL’s scientific name is AHRS IMU sensor.
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. For proper instrument grounding: use WITMOTION with its original factory-made cable or accessories. For secondary developing project or integration: use WITMOTION with its compiled sample code. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2 Use Instructions with PC For configuration setting, it is recommended to connect with the PC software before offline record. 2.1 Connection Method PC software is only compatible with Windows system. Link to WT901SDCL’s demo video 2.1.1 Connection to the Computer This product has an attached cable that connects the computer and the product. Please use the cable that comes with the product.
2.1.2 Indicator Status 1. The product is connected to the power supply. At this time, the power indicator (red) is always on, indicating that the product is charging. The red light will go out after charging is completed. 2. After inserting the SD card for about 1 second, the blue light flashes, indicating that the SD card is recording data. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.1.3 Software Preparation Step 1. Unzip the software and install the driver CH340 Link to CH340 driver Step 2. Plugin the converter to computer and confirm the “com port” in device manager Step 3. 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 9600, data will be shown on the software. WT901SDCL | manual v0707 | http://wiki.wit-motion.
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 DEMO Config Configuration setting Help Language English or Chinese Bluetooth Set Binding device or unbind Firmware update Option for firmware update About Minimu Info about Minimu.
2.2.2 Menu of Configuration Menu of Configuration Button Function Read Config Reading the current configuration Lock Lock the sensor Unlock Unlock the sensor Calibrate Time Calibration time of chip Save Config Save configuration WT901SDCL | manual v0707 | http://wiki.wit-motion.
Menu of System Button Function Reset Reset to factory setting Sleep Sleep function Alarm Alarm function Algorithm 6-axis algorithm or 9-axis Installation Direction Vertical or horizontal installation Instruction Start-up Instructions sending to start-up the sensor Instruction Start-up: This function is used to prevent the data sent by the module after connecting to the computer to conflict with the mouse, causing the mouse to jump.
Menu of Range Button Function Acceleration Acceleration measurement range Gyro Gyroscope measurement range Band Width Bandwidth range GPS Time Zone GPS positioning of time zone Menu of Communication Button Function Baud Rate Baud rate selection Output Rate Return rate selection Device Address Interface for R&D Menu of Content Button Function Time Time data output Acceleration Acceleration data output Velocity Angular velocity data output Angle Angle data output Magnetism Magneti
Quaternion Quaternion data output Positioning Accuracy Option for GPS positioning accuracy output, including Satellite quantity, PDOP, HDOP, VDOP data, only for GPS IMU series, such as WTGAHRS1, WTGAHRS2 GPS Original Only output GPS raw data,only for GPS IMU series, such as WTGAHRS1, WTGAHRS2 Menu of Port D0 Model Extended port D0 D1 Model Extended port D1 D2 Model Extended port D2 D3 Model Extended port D3 Pulse width Pulse width of PWM Cycle Cycle of PWM WT901SDCL | manual v0707 | http:
2.3 Calibration Preparation: Make sure the sensor is “Online”. Calibration on PC software： It is required to calibrate for the first time usage. 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: Step 1. Keep the module horizontally stationary Step 2. Click the accelerometer calibration Step 3.
Step 5. Judge the result--confirm if there is 1g on Z-axis acceleration 1. After1 ~ 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 1g of gravitational acceleration on the Z-axis. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.3.2 Magnetic Field Calibration Purpose: Magnetic calibration is used to remove the zero bias of the magnetic field sensor. Usually, the magnetic field sensor will have a large zero error when it is manufactured. If it is not calibrated, it will bring a large measurement error, which will affect the accuracy of the measurement of the z-axis Angle of the heading Angle. Preparation: Sensors should be 20CM away from magnetic and iron and other materials Methods: Step 1. Open the Config menu Step 2.
Step 3. Slowly rotate the module 360° around X, Y, Z, 3-axis accordingly WT901SDCL | manual v0707 | http://wiki.wit-motion.
Step 4. After rotation, click “End calibration” Successful result: Most of data dots will be within the ellipse. If not successful, please stay away from the objective that can create magnetic field interference. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.3.3 Gyroscope Automatic Calibration The gyroscope calibration is to calibrate the angular velocity, and the sensor will calibrate automatically. It is recommended that the automatic calibration of gyroscopes can be inactivated only if the module rotates at a constant speed. 2.3.4 Reset Z-axis Angle Note：If you want to avoid magnetic interference, you can change the algorithm to Axis 6,then you can use reset function of “ Reset Z-axis angle”.
2.4 Configuration 2.4.1 Return Content Setting method: The content of the data return can be set according to user needs, click the configuration option bar, and check the data content to be output. Taking WT901SDCL as an example, the default output of the module is acceleration, angular velocity, angle, and magnetic field. Notice: If choosing the GPS Original, there will be no other data output. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.2 Output Rate The default return rate of the module is 10Hz, the highest return rate supports 200Hz. 10Hz refers to 10 packets returned every second. There contain 33bytes in a data packet in default. Reminder: If there being many types of return data and low baud rate of communication, the module will automatically reduce the frequency and output at a maximum allowable output rate. If the return rate is high, the baud rate should be set higher, generally 115200.
2.4.3 Baud Rate The module supports multiple baud rates, and the default baud rate is 9600. To set the baud rate of the module, you need to select the baud rate to be changed in the communication rate drop-down box in the configuration bar based on the correct connection between the software and the module. Note: After the change, the module will no longer output data at the original baud rate. The data will be output only when the baud rate that has been changed is selected on the PC software again.
2.4.4 Calibrate Time Method: Step 1: Click “Calibrate Time” in the “ Config” Step 2: Click “Time” Step 3: Notification will be shown if successfully calibrated Step 4. Click “Save Config” WT901SDCL | manual v0707 | http://wiki.wit-motion.
Function: By calibrating the time, the host computer time is the same as the current time. When recording data, you can know when the data was recorded. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.5 Data Recording There is a 16G SD memory card inside the sensor, but the real-time data can still be recorded and saved by the PC software. Instructions as follows: Step 1: Click “Record” and “Begin” Step 2: Click “Stop” WT901SDCL | manual v0707 | http://wiki.wit-motion.
Step 3: Extract the data as “txt” file Notice: If there is repeated “TIME” of data, that’s caused by low-resolution of the Windows system’s time. The changes in other data is correct. The saved file is in the directory of the software Data.tsv: The file begins with a value indicating the data. “Time” stands for time, “ax, ay, az” respectively represents the acceleration of X, Y , Z axis. “wx, wy, wz” respectively represents the angular velocity of X, Y, Z axis.
Data can be imported into the Excel or analysis in Matlab. In the Matlab environment running xxx.m document and it can plot of the data. It is highly recommended that data can be pasted to an Excel file. In this way, all data will be shown in order. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.6 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” Step 3: Choose the original path of software installation and load the Bin file WT901SDCL | manual v0707 | http://wiki.wit-motion.
Step 4: Click “Run” and the Binary file will be playback When playback, the rate can be editable. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.7 File Conversion Tutorial to convert SD card TSV file format data to a TXT one: Step 1: After the data can be played back, click "File Conversion". WT901SDCL | manual v0707 | http://wiki.wit-motion.
Step 2: After the conversion reaches 100%, it will pop up whether to open the converted document and the path of the converted document. Step 3: Click “Yes” to open the document as shown in the figure below, 1 represents the time to convert the document, 2 represents the time to convert the data, and 3 represents the time to record the data. WT901SDCL | manual v0707 | http://wiki.wit-motion.
WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.8 Placement Direction The default installation direction of the module is horizontal. When the module needs to be installed vertically, the vertical installation can be set. Step 1: Rotate the module 90 degrees around the X-axis Step 2: Place the sensor 90 degrees vertically Step 3: Click “Vertical” as install directions on “Config” menu WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.9 Bandwidth Default bandwidth is 20Hz. Function: 1. The higher rate of bandwidth setting will lead to the higher fluctuation in data waveform. Conversely, the lower rate of bandwidth, data will become more fluent. For example: Bandwidth as 20Hz, Output rate as 10Hz. The waveform is very steady. WT901SDCL | manual v0707 | http://wiki.wit-motion.
Bandwidth as 256Hz, Output rate as 10Hz. The waveform will show more fluctuation. 2. The higher rate of bandwidth will solve the data-repeating problem. For example, if the bandwidth setting is 20Hz, retrieval rate as 100Hz, there will be 5 repeating data. If you prefer there is no repeating data, it is required to increase the bandwidth more than 100Hz. WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.10 Restore Factory Setting Command method: Step 1: Connect the WT901SDCL module and the computer through the cable that comes with. Step 2: Click the Settings tab, and click to “Reset”. Step 3: After restoring the factory settings, you need to power on the module again. (This method needs to know the baud rate of the module in advance if the baud rate does not match the instruction will not take effect). WT901SDCL | manual v0707 | http://wiki.wit-motion.
2.4.11 6-axis/ 9-axis Algorithm 6-axis algorithm: Z-axis angle is mainly calculated based on angular velocity integral. There will be calculated error on Z-axis angle. 9-axis algorithm: Z-axis angle is mainly calculated and analyzed based on the magnetic field. Z-axis angle will have few drift. The default algorithm of WT901SDCL is 9-axis. If there is magnetic field interference around installed environment, it is recommended to switch to 6-axis algorithm to detect the angle.
3 3.1 Offline Record Guidelines 1. Offline record requires the configuration of calibrating time. So the data will have a “Time” to know when the data starts to be recorded. There will be a 16G SD card and a SD card reader came with the sensor as accessory. ((Please refer to Chapter 2.4.4) 2. In this product, the SD card is mainly used to record data. Only when the SD card is inserted will the product start to work and the data will be transferred. 3.
3.2 Instructions Link to WT901SDCL’s demo video Step 1. Disconnect with the computer (Unplug the cable) Step 2. Measure the data (install the sensor as you prefer) Step 3. Remove the SD card and insert it into the card reader Step 4. Plugin the reader and Open Minimu.exe WT901SDCL | manual v0707 | http://wiki.wit-motion.
Step 5. Select the recorded file from the USB Drive path and load the recorded file, click the “Run” and data will be playback WT901SDCL | manual v0707 | http://wiki.wit-motion.
Step 6. Convert the recorded file to txt format. It would be better to review. (Please refer to Chapter 2.4.7) WT901SDCL | manual v0707 | http://wiki.wit-motion.
