Bluetooth 5.0 protocol: It is the protocol used by WitMotion Bluetooth 5.0 sensors; the protocol stipulates that the sensor returns data packets beginning with 55, and the host computer sends data packets beginning with FF AA; Bluetooth 5.0 protocol: It is the protocol used by WitMotion Bluetooth
Routine Introduction
This routine introduces how to use C# to develop the upper computer to connect to the Bluetooth 5.0 protocol sensor, receive sensor data and communicate with the sensor; Before viewing this routine, please read the relevant sensor manual to understand the protocol used by the sensor and the basic functions of the sensor
Routine Diretory
The routine project directory is as follows
Dll: The dependent files of the project, please import these dlls into your project before running the project.
Form1：There is only one Form window in the routine, all logic codes are in the Form window file, and there are no other files
Open Search
The BWT901BLE object represents the BWT901BLE device in the program, and you can communicate with the device through it; when searching for devices, call bluetoothManager.StartScan() to start searching; when opening the device, you need to specify the Bluetooth address of the Bluetooth sensor, and call BWT901BLE.Open() after specifying method
/// <summary>
/// start searching
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void startScanButton_Click(object sender, EventArgs e)
{
// Clear found devices
FoundDeviceDict.Clear();
// Close previously opened devices
for (int i = 0; i < FoundDeviceDict.Count; i++)
{
var keyValue = FoundDeviceDict.ElementAt(i);
BWT901BLE bWT901BLE = keyValue.Value;
bWT901BLE.Close();
}
// Let the bluetooth manager start searching for devices
WitBluetoothManager bluetoothManager = WitBluetoothManagerHelper.GetWitBluetoothManager();
bluetoothManager.OnDeviceFound += new WitBluetoothManager.OnDeviceFoundHalder(OnFoundDevice);
bluetoothManager.OnDeviceStatu += new WitBluetoothManager.OnDeviceStatuHalder(OnDeviceStatu);
bluetoothManager.StartScan();
}
/// <summary>
///This method will be called back when a Bluetooth device is found
/// </summary>
/// <param name="macAddr"></param>
/// <param name="sName"></param>
/// <param name="dType"></param>
/// <param name="mType"></param>
private void OnFoundDevice(string macAddr, string sName, int dType, int mType)
{
// If the Bluetooth device starting with WT is found
if (sName != null && sName.Contains("WT"))
{
/ If the device is newly found
if (FoundDeviceDict.ContainsKey(macAddr) == false)
{
BWT901BLE bWT901BLE = new BWT901BLE();
//Specify the Bluetooth MAC code for the connection
bWT901BLE.SetMacAddr(macAddr);
// set device name
bWT901BLE.SetDeviceName(sName);
FoundDeviceDict.Add(macAddr, bWT901BLE);
// turn on this device
bWT901BLE.Open();
bWT901BLE.OnRecord += BWT901BLE_OnRecord;
}
}
}
Close the search
Close the search and call the bluetoothManager.StopScan() method
The BWT901BLE object will automatically calculate the sensor data and save it on itself. The sensor data can be obtained through the BWT901BLE.GetDeviceData() method. BWT901BLE.GetDeviceData() needs to pass in a key to get sensor data. Please check the key that needs to be used in the routine, the key is stored in the WitSensorKey class
/// <summary>
/// Get device data
/// </summary>
private string GetDeviceData(BWT901BLE BWT901BLE)
{
StringBuilder builder = new StringBuilder();
builder.Append(BWT901BLE.GetDeviceName()).Append("\n");
// acceleration
builder.Append("AccX").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AccX)).Append("g \t");
builder.Append("AccY").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AccY)).Append("g \t");
builder.Append("AccZ").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AccZ)).Append("g \n");
// angular velocity
builder.Append("GyroX").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AsX)).Append("°/s \t");
builder.Append("GyroY").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AsY)).Append("°/s \t");
builder.Append("GyroZ").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AsZ)).Append("°/s \n");
// angle
builder.Append("AngleX").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AngleX)).Append("° \t");
builder.Append("AngleY").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AngleY)).Append("° \t");
builder.Append("AngleZ").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.AngleZ)).Append("° \n");
// magnetic field
builder.Append("MagX").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.HX)).Append("uT \t");
builder.Append("MagY").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.HY)).Append("uT \t");
builder.Append("MagZ").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.HZ)).Append("uT \n");
//version number
builder.Append("VersionNumber").Append(":").Append(BWT901BLE.GetDeviceData(WitSensorKey.VersionNumber)).Append("\n");
return builder.ToString();
}
Record data
The data of the sensor can be obtained through the BWT901BLE object, but usually the host computer needs to record the data of the sensor. BWT901BLE has an OnRecord event that will notify you when the data should be recorded, and the OnRecord event can be realized when the device is turned on; and then through cooperation with BWT901BLE.GetDeviceData( ) method to record the data
/// <summary>
/// This method will be called back when a Bluetooth device is found
/// </summary>
/// <param name="macAddr"></param>
/// <param name="sName"></param>
/// <param name="dType"></param>
/// <param name="mType"></param>
private void OnFoundDevice(string macAddr, string sName, int dType, int mType)
{
// If the Bluetooth device starting with WT is found
if (sName != null && sName.Contains("WT"))
{
// If the device is newly found
if (FoundDeviceDict.ContainsKey(macAddr) == false)
{
BWT901BLE bWT901BLE = new BWT901BLE();
// Specify the Bluetooth MAC code for the connection
bWT901BLE.SetMacAddr(macAddr);
// set device name
bWT901BLE.SetDeviceName(sName);
FoundDeviceDict.Add(macAddr, bWT901BLE);
// turn on this device
bWT901BLE.Open();
bWT901BLE.OnRecord += BWT901BLE_OnRecord;
}
}
}
/// <summary>
/// This is called when the sensor data is refreshed, you can log the data here
/// </summary>
/// <param name="BWT901BLE"></param>
private void BWT901BLE_OnRecord(BWT901BLE BWT901BLE)
{
string text = GetDeviceData(BWT901BLE);
Debug.WriteLine(text);
}
BWT901BLE.StartFieldCalibration() Send start magnetic field calibration command
BWT901BLE.EndFieldCalibration() Send end magnetic field calibration command
BWT901BLE.SendProtocolData() send other commands
Accelerometer Clibration
Applied calibration of the sensor by calling the BWT901BLE.AppliedCalibration() method
/// <summary>
/// Accelerometer Calibration
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void appliedCalibrationButton_Click(object sender, EventArgs e)
{
// All connected Bluetooth devices are calibrated
for (int i = 0; i < FoundDeviceDict.Count; i++)
{
var keyValue = FoundDeviceDict.ElementAt(i);
BWT901BLE bWT901BLE = keyValue.Value;
if (bWT901BLE.IsOpen() == false)
{
return;
}
try
{
// Unlock registers and send commands
bWT901BLE.UnlockReg();
bWT901BLE.AppliedCalibration();
// The following two lines are equivalent to the above, it is recommended to use the above
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x69, 0x88, 0xb5 });
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x01, 0x01, 0x00 });
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
Magnetic field calibration
Calibrate the magnetic field of the sensor by calling the BWT901BLE.StartFieldCalibration() method and the BWT901BLE.EndFieldCalibration() method
/// <summary>
///Start Magnetic Field Calibration
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void startFieldCalibrationButton_Click(object sender, EventArgs e)
{
// Start magnetic field calibration of all connected bluetooth devices
for (int i = 0; i < FoundDeviceDict.Count; i++)
{
var keyValue = FoundDeviceDict.ElementAt(i);
BWT901BLE bWT901BLE = keyValue.Value;
if (bWT901BLE.IsOpen() == false)
{
return;
}
try
{
// Unlock registers and send commands
bWT901BLE.UnlockReg();
bWT901BLE.StartFieldCalibration();
// The following two lines are equivalent to the above, it is recommended to use the above
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x69, 0x88, 0xb5 });
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x01, 0x07, 0x00 });
MessageBox.Show("Start magnetic field calibration, please turn around the sensor's XYZ three axes, and click [End Magnetic Field Calibration]");
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
/// <summary>
/// End magnetic field calibration
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void endFieldCalibrationButton_Click(object sender, EventArgs e)
{
// End magnetic field calibration for all connected bluetooth devices
for (int i = 0; i < FoundDeviceDict.Count; i++)
{
var keyValue = FoundDeviceDict.ElementAt(i);
BWT901BLE bWT901BLE = keyValue.Value;
if (bWT901BLE.IsOpen() == false)
{
return;
}
try
{
//Unlock registers and send commands
bWT901BLE.UnlockReg();
bWT901BLE.EndFieldCalibration();
// The following two lines are equivalent to the above, it is recommended to use the above
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x69, 0x88, 0xb5 });
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x01, 0x00, 0x00 });
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
}
More
Pleaes reference to the sensor datasheet.
Read sensor register
The register of the sensor can be read through the BWT901BLE.SendReadReg() method, or the BWT901BLE.SendProtocolData() method can be used
After sending the read command, the register value will be saved in BWT901BLE, you need to get the register data through BWT901BLE.GetDeviceData()
/// <summary>
/// Read 03 register
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void readReg03Button_Click(object sender, EventArgs e)
{
string reg03Value = "";
// Read the 03 registers of all connected bluetooth devices
for (int i = 0; i < FoundDeviceDict.Count; i++)
{
var keyValue = FoundDeviceDict.ElementAt(i);
BWT901BLE bWT901BLE = keyValue.Value;
if (bWT901BLE.IsOpen() == false)
{
return;
}
try
{
// waiting time
int waitTime = 3000;
// Send a read command and wait for the sensor to return data. If it is not read, you can extend the waitTime, or read it several times
bWT901BLE.SendReadReg(0x03, waitTime);
// The following line is equivalent to the above. It is recommended to use the above
//bWT901BLE.SendProtocolData(new byte[] { 0xff, 0xaa, 0x27, 0x03, 0x00 }, waitTime);
// Get the value of all connected bluetooth devices
reg03Value += bWT901BLE.GetDeviceName() + "The value of register 03:" +bWT901BLE.GetDeviceData("03") + "\r\n";
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}
}
MessageBox.Show(reg03Value);
}
BWT901BLE API
Method
Illustrate
Parameter introduction
Return value
void SetMacAddr(string macAddr)
Set the bluetooth address to open
macAddr：bluetooth address
void
void SetDeviceName(string DeviceName)
set device name
DeviceName：device name
void
void Open()
turn on the device
none
void
bool IsOpen()
Is the device turned on
none
返回是否打开打开：true关闭：false
void Close()
turn off the device
nones
void
void SendData(byte[] data, out byte[] returnData, bool isWaitReturn, int waitTime , int repetition)
send data
data: the data to be sent returnData: the data returned by the sensor isWaitReturn: Whether the sensor needs to return data waitTime: wait for the sensor to return data time, unit ms, default 100ms repetition: the number of times to repeat sending
void
void SendProtocolData(byte[] data)
send protocol data
data：data to send
void
void SendProtocolData(byte[] data, int waitTime)
Send data with protocol, and specify the waiting time
