• Go Direct Motion
• Micro USB Cable

Choose a platform below to see its compatibility requirements.

LabQuest

Interface	LabQuest App
LabQuest 3	Full support
LabQuest 2 (discontinued)	Full support 1
LabQuest (discontinued)	Incompatible

Compatibility Notes

1. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.

Computers

	Software
Interface	Graphical Analysis
No interface required	Full support 1
LabQuest 3	Full support 2
LabQuest 2 (discontinued)	Full support 2 3

Compatibility Notes

1. For Bluetooth^® connectivity, only computers running Windows 10 or Mac OS X 10.10 or newer are supported. The computer must also have a compatible Bluetooth 4.0⁺ radio.
2. Connect this sensor directly to a computer or Chromebook via a USB or wireless Bluetooth^® connection for best results. Alternatively, this sensor is fully supported when used with LabQuest 2 or LabQuest 3 when the LabQuest is connected to a computer or Chromebook via Wireless Data Sharing.
3. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.

Chromebook

	Software
Interface	Graphical Analysis
No interface required	Full support
LabQuest 3	Full support 1
LabQuest 2 (discontinued)	Full support 1 2

Compatibility Notes

1. Connect this sensor directly to a computer or Chromebook via a USB or wireless Bluetooth^® connection for best results. Alternatively, this sensor is fully supported when used with LabQuest 2 or LabQuest 3 when the LabQuest is connected to a computer or Chromebook via Wireless Data Sharing.
2. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.

iOS

	Software
Interface	Graphical Analysis	Graphical Analysis GW
No interface required	Full support	Full support
LabQuest 3	Full support 1 2	Full support 1 2
LabQuest 2 (discontinued)	Full support 1 2 3	Full support 1 2 3

Compatibility Notes

1. Connect this sensor directly to a supported mobile device via a wireless Bluetooth^® connection for best results.
2. iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
3. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.

Android

	Software
Interface	Graphical Analysis	Graphical Analysis GW
No interface required	Full support	Incompatible
LabQuest 3	Full support 1 2	Full support 1
LabQuest 2 (discontinued)	Full support 1 2 3	Full support 1 3

Compatibility Notes

1. iOS and Android^™ devices can only connect to LabQuest 2 or LabQuest 3 via Wireless Data Sharing.
2. Connect this sensor directly to a supported mobile device via a wireless Bluetooth^® connection for best results.
3. Wireless connection of this sensor to a LabQuest 2 requires a Go Direct Bluetooth Adapter when used with some older LabQuest 2 models.

Python

	Software
Interface	Python
No interface required	Full support

Javascript

	Software
Interface	Javascript
No interface required	Full support 1

Compatibility Notes

1. A wireless Bluetooth^® connection can be made with Go Direct sensors on any platform running a browser with WebBluetooth support. However, only a few operating systems have been tested and testing has been limited.

LabVIEW

	Software
Interface	NI LabVIEW
No interface required	Full support 1

Compatibility Notes

1. For Bluetooth^® connectivity, only computers running Windows 10 or Mac OS X 10.10 or newer are supported. The computer must also have a compatible Bluetooth 4.0⁺ radio.

Connect Go Direct Motion to the included USB Charging Cable and any USB device for two hours.

You can also charge up to eight Go Direct Motion Detectors using our Go Direct Charge Station, sold separately (order code: GDX-CRG). An LED on each Go Direct Motion indicates charging status.

Charging	Orange LED next to the battery icon is solid while the sensor is charging.
Fully charged	Green LED next to the battery icon is solid when the sensor is fully charged.

Turning on the sensor	Press button once. Red LED indicator flashes when unit is on.
Putting the sensor in sleep mode	Press and hold button for more than three seconds to put into sleep mode. Red LED indicator stops flashing when sleeping.

See the following link for up-to-date connection information:

www.vernier.com/start/gdx-md

Connecting via Bluetooth

Ready to connect	Red LED next to the Bluetooth icon flashes when sensor is awake and ready to connect.
Connected	Green LED next to the Bluetooth icon flashes when sensor is connected via Bluetooth.

Connecting via USB

Connected and charging	Orange LED next to the battery icon is solid when the sensor is connected to Graphical Analysis via USB and the unit is charging. LED next to Bluetooth icon is off.
Connected, fully charged	Green LED next to the battery icon is solid when the sensor is connected to Graphical Analysis via USB and fully charged. LED next to Bluetooth icon is off.
Charging via USB, connected via Bluetooth	Orange LED next to the battery icon is solid when the sensor is charging. Green LED next to the Bluetooth icon flashes.

When two or more sensors are connected, the sensors can be identified by tapping or clicking Identify in Sensor Information.

Connect the sensor following the steps in the Getting Started section of this user manual.

Channels

Go Direct Motion has three measurement channels. The channel names are

• Motion
• Motion (cart)
• Motion with TC

Motion

The default channel that is active when the sensor is connected is motion. The motion channel is set to measure the distance between the sensor and the nearest object based on the speed of sound at 22°C. This channel has a high gain and is best for most uses, such as measuring the motion of a tossed ball, a walking student, or a mass on a spring.

Motion (cart)

This channel has a lower gain setting than the default motion channel. It is useful for measuring a cart on a track as this channel is less likely to pick up objects to either side of the track. Use this channel for small objects close to the motion detector.

Motion with TC

Use the motion with TC channel for automatic temperature compensation, which adjusts the speed of sound used in the distance calculation based on an internal temperature sensor. This is particularly useful if you are using the sensor in an environment that is much warmer or much cooler than room temperature.

In most cases, calibration is unnecessary. If you require better accuracy, select the Motion channel and perform a 1-point calibration based on a measured distance. You can make several adjustments to the readings by zeroing and changing the direction of the coordinate system. You can find details on how to adjust these readings at www.vernier.com/til/2972

Motion and Motion (cart) Channels

The default for this channel uses the speed of sound at 22°C. If you would like to calibrate the sensor to improve accuracy, place a hard, flat surface (such as a wall, book, or box) a known distance away from the front surface of Go Direct Motion and choose calibrate. Note that the calibration will be saved to the sensor, so the next time you use this channel it will use the previously saved value.

Motion with TC Channel

This channel adjusts automatically based on the temperature and cannot be calibrated.

Range	Motion and Motion with TC channels: 0.25 m to 3.5 m Motion (cart) channel: 0.15 m to 3.5 m
Resolution	1 mm
Temperature compensation	Motion and Motion (cart) channels: Factory calibrated for room temperature. Calibrate to a known distance for improved distance accuracy. Motion with TC channel: Uses internal temperature sensor to respond to dynamic temperature changes
Accuracy	2 mm
Ultrasound frequency	50 kHz
Power consumption	51 mA
Maximum sampling rate	30 samples/s
USB specification	USB 2.0 full speed
Wireless specification	Bluetooth v4.2
Maximum wireless range	30 m (unobstructed)
Battery	650 mA Li-Poly
Battery life (single full charge)	~24 hours
Battery life (long term)	~500 full charge cycles (several years depending on usage)

Battery Information

Go Direct Motion contains a small lithium-ion battery. The system is designed to consume very little power and not put heavy demands on the battery. Although the battery is warranted for one year, the expected battery life should be several years. Replacement batteries are available from Vernier (order code: GDX-BAT-650).

Storage and Maintenance

To store Go Direct Motion for extended periods of time, put the device in sleep mode by holding the button down for at least three seconds. The red LED will stop flashing to show that the unit is in sleep mode. Over several months, the battery will discharge but will not be damaged. After such storage, charge the device for a few hours, and the unit will be ready to go.

Exposing the battery to temperatures over 35°C (95°F) will reduce its lifespan. If possible, store the device in an area that is not exposed to temperature extremes.

Water Resistance

Go Direct Motion is not water resistant and should never be immersed in water.

If water gets into the device, immediately power the unit down (press and hold the power button for more than three seconds). Disconnect the sensor and charging cable, and remove the battery. Allow the device to dry thoroughly before attempting to use the device again. Do not attempt to dry using an external heat source.

Go Direct Motion emits short bursts of ultrasonic sound waves from the gold foil of the transducer. These waves fill a cone-shaped area about 15 to 20° off the axis of the center line of the beam. Go Direct Motion then “listens” for the echo of these ultrasonic waves returning to it. The equipment measures how long it takes for the ultrasonic waves to make the trip from Go Direct Motion to an object and back. Using this time and the speed of sound in air, the distance to the nearest object is determined.

Note that Go Direct Motion will report the distance to the closest object that produces a sufficiently strong echo. Go Direct Motion can pick up objects such as chairs and tables in the cone of ultrasound.

The sensitivity of the echo detection circuitry automatically increases, in steps, every few milliseconds as the ultrasound travels out and back. This change in sensitivity enables the detection of weaker signals.

The most frequently reported problems with a motion detector are that the motion does not work beyond a certain distance or that the graph is very noisy. There are a number of ways to troubleshoot these situations, and they are described below.

1. If Go Direct Motion does not work beyond a certain distance (e.g., it does not detect anything beyond 1.2 m), here are some things to check if you have this problem:
   • Check for movable objects (textbooks, ring stands, etc.) in the cone of the ultrasound. If possible, move these objects out of the measurement cone. It may not take a very large object to cause problems.
   • Check for a stationary object (chair, table, etc.) in the cone of the ultrasound. This object may be detected when you are trying to study an object farther away. It may not take a very large object to cause problems. If you have trouble with a stationary object causing unwanted echoes, try setting the equipment up so that the objects are not in the cone or placing a cloth over the object. This minimizes the ultrasound reflection.
2. Noisy or erratic data may have a number of causes. Here are some tips.
   • Sometimes other sound sources can cause problems. If there is another source of ultrasonic waves in the same frequency range, this will cause erroneous readings. Examples include motors and fans, air track blowers, the sound made by the air exiting the holes on an air track, etc. Try to eliminate these sources of noise. If you are using an air track, try changing the air flow volume.
   • Make sure that Go Direct Motion is not placed close to a computer or computer monitor.
   • If the room in which Go Direct Motion is being used has a lot of hard, sound‑reflecting surfaces, you can get strange effects caused by the ultrasound bouncing around the room. Standing waves can be set up between Go Direct Motion and a sound reflector. Try placing a cloth horizontally just in front of and below the Motion Detector. This sometimes helps eliminate ultrasound that is “skipping” into the Go Direct Motion.
   • Try changing the data-collection rate. Sometimes motion detectors work better at one data rate than another. Rates above 30 Hz do not work well in acoustically live rooms.
   • If you are studying people moving, have them hold a large, flat object (e.g., a large book or a pizza box) as a reflector. If you have an irregular reflecting surface, sometimes the waves will be reflected back to the transducer, and sometimes not. The results will seem erratic.

An excellent discussion of motion detector theory and operation can be found in “Physics and Technical Characteristics of Ultrasonic Sonar Systems”, Dan MacIsaac and Ari Hamalainen, The Physics Teacher 40, 39–46 (January 2002).

For additional troubleshooting and FAQs, see www.vernier.com/til/4112

If you have watched the related product video(s), followed the troubleshooting steps, and are still having trouble with your Go Direct Motion, contact Vernier Technical Support at support@vernier.com or call 888-837-6437. Support specialists will work with you to determine if the unit needs to be sent in for repair. At that time, a Return Merchandise Authorization (RMA) number will be issued and instructions will be communicated on how to return the unit for repair.

Item	Order Code
Micro USB Cable	CB-USB-MICRO
USB-C to Micro USB Cable	CB-USB-C-MICRO
Go Direct 650 mAh Replacement Battery	GDX-BAT-650
Motion Detector Clamp	MD-CLAMP
Motion Detector Bracket	DTS-MDB