IMU Rotation Vector
This example shows rotation vector output at 400 Hz rate using the onboard IMU. Returns quaternion.Demo
Example script outputCommand Line
1~/depthai-python/examples$ python3 imu_rotation_vector.py
2Rotation vector timestamp: 0.000 ms
3Quaternion: i: 0.089355 j: 0.355103 k: 0.034058 real: 0.929932
4Accuracy (rad): 3.141602
5Rotation vector timestamp: 3.601 ms
6Quaternion: i: 0.088928 j: 0.354004 k: 0.036560 real: 0.930298
7Accuracy (rad): 3.141602
8Rotation vector timestamp: 6.231 ms
9Quaternion: i: 0.094604 j: 0.344543 k: 0.040955 real: 0.933105
10Accuracy (rad): 3.141602
Setup
Please run the install script to download all required dependencies. Please note that this script must be ran from git context, so you have to download the depthai-python repository first and then run the scriptCommand Line
1git clone https://github.com/luxonis/depthai-python.git
2cd depthai-python/examples
3python3 install_requirements.py
Source code
Python
C++
PythonGitHub
1#!/usr/bin/env python3
2
3import cv2
4import depthai as dai
5import time
6import math
7
8device = dai.Device()
9
10imuType = device.getConnectedIMU()
11imuFirmwareVersion = device.getIMUFirmwareVersion()
12print(f"IMU type: {imuType}, firmware version: {imuFirmwareVersion}")
13
14if imuType != "BNO086":
15 print("Rotation vector output is supported only by BNO086!")
16 exit(1)
17
18# Create pipeline
19pipeline = dai.Pipeline()
20
21# Define sources and outputs
22imu = pipeline.create(dai.node.IMU)
23xlinkOut = pipeline.create(dai.node.XLinkOut)
24
25xlinkOut.setStreamName("imu")
26
27# enable ROTATION_VECTOR at 400 hz rate
28imu.enableIMUSensor(dai.IMUSensor.ROTATION_VECTOR, 400)
29# it's recommended to set both setBatchReportThreshold and setMaxBatchReports to 20 when integrating in a pipeline with a lot of input/output connections
30# above this threshold packets will be sent in batch of X, if the host is not blocked and USB bandwidth is available
31imu.setBatchReportThreshold(1)
32# maximum number of IMU packets in a batch, if it's reached device will block sending until host can receive it
33# if lower or equal to batchReportThreshold then the sending is always blocking on device
34# useful to reduce device's CPU load and number of lost packets, if CPU load is high on device side due to multiple nodes
35imu.setMaxBatchReports(10)
36
37# Link plugins IMU -> XLINK
38imu.out.link(xlinkOut.input)
39
40# Pipeline is defined, now we can connect to the device
41with device:
42 device.startPipeline(pipeline)
43
44 def timeDeltaToMilliS(delta) -> float:
45 return delta.total_seconds()*1000
46
47 # Output queue for imu bulk packets
48 imuQueue = device.getOutputQueue(name="imu", maxSize=50, blocking=False)
49 baseTs = None
50 while True:
51 imuData = imuQueue.get() # blocking call, will wait until a new data has arrived
52
53 imuPackets = imuData.packets
54 for imuPacket in imuPackets:
55 rVvalues = imuPacket.rotationVector
56
57 rvTs = rVvalues.getTimestampDevice()
58 if baseTs is None:
59 baseTs = rvTs
60 rvTs = rvTs - baseTs
61
62 imuF = "{:.06f}"
63 tsF = "{:.03f}"
64
65 print(f"Rotation vector timestamp: {tsF.format(timeDeltaToMilliS(rvTs))} ms")
66 print(f"Quaternion: i: {imuF.format(rVvalues.i)} j: {imuF.format(rVvalues.j)} "
67 f"k: {imuF.format(rVvalues.k)} real: {imuF.format(rVvalues.real)}")
68 print(f"Accuracy (rad): {imuF.format(rVvalues.rotationVectorAccuracy)}")
69
70
71 if cv2.waitKey(1) == ord('q'):
72 break
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