Go Direct® Motion Detector (GDX-MD)
Specifications and User Guide

– Primary Test: Press the power button on the sensor to turn it on. (The red LED will flash.) Start the Graphical Analysis or Graphical Analysis Pro app on your device and select the sensor from the list of available sensors. (The green LED will flash.)
– Test 2: If the Motion Detector is not working when connected by USB, it may be the cable that is bad and not the sensor. Try a cable from a working unit.
– Test 3: To test accuracy, find a wall with no desks, chairs, doors, or other obstructions within a 2 m field. Hold the motion detector in your hand, 0.5 m from the wall with the sensor pointing directly at the wall. Do you get the expected 0.5 m reading? Back off to 1.0 m. Do you get 1.0 m? Back further off to 1.5 m. Do you get 1.5 m?

– Tip 1: The optimum collection rate is 20 pts/second, and the maximum sample rate that you can use for the Go Direct Motion is 30 Hz
– Tip 2: Clear all objects within the 30 degree cone.
– Tip 3: Increase the target’s area, for example by taping an index card to the object such that the ultrasound will detect the flat surface of the card.

For more detailed usage tips, see Why am I getting Motion Detector readings that are noisy or max out at a certain distance?

– 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: 0.001 m

– The Motion channel (which is the default channel) and the Motion (cart) channel are factory calibrated. You can calibrate these channels for better accuracy by placing a flat object such as a book, box, or wall a measured distance from the front surface of the sensor housing and performing a one-point calibration.
– The Motion with TC channel cannot be calibrated. It uses an internal temperature sensor to determine the speed of sound to be used in calculations.

Sensor dimensions:
– Length: 6.5 cm
– Width: 6.4 cm
– Height: 6.8 cm


Why am I getting Motion Detector readings that are noisy or max out at a certain distance?
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Is there a way to calibrate the Motion Detector?

Which motion detector should I buy? What are the differences between them?
Which Motion Detector model do I have?

Go Direct® 650 mAh Replacement Battery (GDX-BAT-650)
Micro USB Cable (CB-USB-MICRO)

Motion Detector Clamp (MD-CLAMP)
Go! Motion (GO-MOT)
Motion Detector Bracket (DTS-MDB)
Motion Detector (MD-BTD)
CBR 2 (CBR2)