The sensor fusion test measures timestamp accuracy of of sensors for Android devices, specifically camera image sensors and gyroscopes. This page provides step-by-step directions on how to setup the Sensor Fusion test and Sensor Fusion Box for the first time.
Required tools
Before getting started, ensure you have the following components:

- USB A to B cable
- USB A to C cable (for test phone)
- 12V 2A power cord (for servo control box)
- 12V power cord (for lighting, with switch)
- 5V male-male connection cable (for lighting)
- 5V male-female conversion cable (for lighting)
Step 1: Connect lights
To connect the lights:
- Use the male-male cable to connect the two lights on the bottom ends of the lights as shown in figure 2. Secure the cable to the bottom of the box to keep the cable from interfering with the operation.
- Connect the end of the light closer to the light cable exit hole to
the conversion cable
Figure 2. Connecting the lights to each other and one light to the conversion cable - Light cable exit hole
- USB cable exit hole
- 5V male-male conversion cable
- Thread the unconnected end of the conversion cable through the round
hole that exits the box, then connect it to the power
cable for lighting.
Figure 3. Lighting conversion cable exiting the box and connecting to power cable - Exit hole
- Conversion cable
- Power cable
Step 2: Attach servo
To attach the servo:
- Plug the servo connector into the servo control. Be sure to insert
the connector oriented to the corresponding colors as labeled (Y =
Yellow, R = Red, B = Black), as reversing the order could damage the
motor. If the cord is too short, use a
servo extension cable.
Figure 4. Servo connecting to the servo control box - Connect the servo control with its power cord (the lighting and
servo control have independent, dedicated power supplies as shown in
figure 5).
Figure 5. Connecting the servo control to its dedicated power cord - Power for servo control
- Power for lighting
- Use the USB A to B cable to connect the servo control box to the
host (machine that is running the test).
Figure 6. Connecting the servo control box to the host machine
Step 3: Attach phone
- Set the phone on the fixture and clamp it down.
Figure 7. Placing and clamping the phone on the fixture - Back support
- Tightness
Phones should be placed in a manner where the USB cords are located at the periphery of the phone mount and the cameras are near the center of the mount.
The upside-down thumb screw provides back support while the other screw tightens the grip by turning right. For more details, see video on how to attach the phone.
- Use a zip tie to hold the phone USB cord to the fixture plate and
lead it outside the box through the exit hole. Plug the other end
of the cord to the host running the test.
Figure 8. Phone USB cord held to fixture with zip ties
Step 4: Run test script
The main python executable for the test script is:
python tools/run_all_tests.py device=ID camera=0 scenes=sensor_fusion rot_rig=default
You can modify the command to specify the actual rotator address by using:
rot_rig=VID:PID:CH
- To determine the Vendor ID (VID) and Product ID (PID), use the Linux
command
lsusb
. - By default, the VID and PID are set
to
04d8
andfc73
with channel "1".
Multiple runs, different formats
To perform multiple runs with different formats, you can use a
different script (however, the results will not be uploaded to
CtsVerifier.apk
). Sample test script:
python tools/run_sensor_fusion_box.py device=FA7831A00278 camera=0 rotator=default img_size=640,360 fps=30 test_length=7
Permission issues
To resolve permission issues related to controlling the motor through the USB port:
- Add the operator username to the
dialout
group using:sudo adduser USERNAME dialout
- Log out the operator.
- Log in the operator.
Adjusting the motor
You can adjust the speed of the motor and the distance the phone travels using the resistance ports (labeled A, B, and T) on the side of the controller box.
- Upon first receiving the box, power up the box and determine the initial position. If the initial position on power-up is not close to 12 o'clock, unscrew the phone fixture (single Philips head screw in mount hole) and rotate the phone fixture to 12 o'clock.
- Ensure the phone fixture travels a full 90 degrees (from 12
o'clock to 9 o'clock when looking at the phone) for each rotation.
- To adjust the distance traveled, use the A and B screws (where A is the starting location and B is the final location).
- Adjust the rotation speed to travel a full rotation in 1.5s. Turning
the resistor pot clockwise slows down the motion.
- A is the start position of the fixture.
- B is the end position of the fixture.
- T is the speed motor rotates.
For more information, see video tutorials.