{"id":4112,"date":"2018-03-08T22:39:42","date_gmt":"2018-03-09T06:39:42","guid":{"rendered":""},"modified":"2025-07-16T13:54:41","modified_gmt":"2025-07-16T20:54:41","slug":"4112","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/4112","title":{"rendered":"Go Direct Motion Troubleshooting and FAQs"},"content":{"rendered":"<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-vertically-aligned-center is-layout-flow wp-block-column-is-layout-flow\">\n<h3 class=\"wp-block-heading\"><a href=\"\/product\/go-direct-motion-detector\/\">Go Direct<sup>&reg;<\/sup> Motion Detector<\/a> (<nobr>GDX-MD<\/nobr>)<\/h3>\n<ul class=\"wp-block-list\">\n<li><a href=\"\/manuals\/GDX-MD\">Specifications and User Guide<\/a><\/li>\n<li><a href=\"\/til\/3269\/\">Which Motion Detector model do I have?<\/a><\/li>\n<\/ul>\n<\/div>\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<figure class=\"wp-block-image size-large\"><img decoding=\"async\" src=\"https:\/\/www.vernier.com\/wp-content\/uploads\/2019\/12\/product.gdx-md._hero.001-e1705617795699.jpg\" alt=\"\"\/><\/figure>\n<\/div>\n<\/div>\n<h3 class=\"wp-block-heading\">Troubleshooting<\/h3>\n<p class=\"wp-block-paragraph\">Press the power button on the sensor to turn it on. Connect your sensor as described in the <a href=\"https:\/\/www.vernier.com\/til\/get-started\/go-direct\">Getting Started instructions for your device<\/a>.<\/p>\n<ul class=\"wp-block-list\">\n<li><strong>Primary test:<\/strong> Do you hear a clicking from the motion detector when connected to the data collection app? If not, the sensor may be defective. <\/li>\n<li><strong>Secondary test:<\/strong> If the Motion Detector is not working when connected via USB, the cable could be malfunctioning. Try a cable from a sensor.<\/li>\n<li><strong>Tertiary test:<\/strong> 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 gold disc 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 farther off to 1.5 m. Do you get 1.5 m?<\/li>\n<li><strong>Quaternary test:<\/strong> Motion Detectors use ultrasound to measure position. Other sources of ultrasound may be interfering with the signal. Those sources include air tracks, CRT computer monitors, fluorescent lights, and power distribution panels. Identifying these sources can be challenging. You may have to resort to moving the Motion Detector away from interfering equipment. In the case of noisy fluorescent lights, turn them off (but we rarely see this problem).<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<h3 class=\"wp-block-heading\">Usage Tips<\/h3>\n<ul class=\"wp-block-list\">\n<li><strong>Tip 1:<\/strong> The optimum collection rate is 20 samples\/second. The maximum sample rate that you can use for this motion detector is 30 samples\/second.<\/li>\n<li><strong>Tip 2:<\/strong> Clear all objects within the 30\u00ba cone.<\/li>\n<li><strong>Tip 3:<\/strong> If you are monitoring the motion of objects on a table or track, use the Motion (cart) sensor channel. (See <a href=\"\/til\/20039\/\">How can change the sensor channels used with data collection for Go Direct sensors having multiple sensor channels?<\/a>)<\/li>\n<li><strong>Tip 4:<\/strong> Increase the target\u2019s area (e.g., tape an index card to the object such that the ultrasound will detect the flat surface of the card).<\/li>\n<li><strong>Tip 5:<\/strong> Noisy velocity data: increase the number of points used for derivative calculations. See <a href=\"\/til\/2331\/\">How do I adjust the number of points used in derivative calculations?<\/a><\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<h3 class=\"wp-block-heading\">Additional Troubleshooting<\/h3>\n<ul class=\"wp-block-list\">\n<li><a href=\"\/til\/5\/\">Why am I getting Motion Detector readings that are noisy or max out at a certain distance?<\/a><\/li>\n<li><a href=\"\/til\/18404\/\">Go Direct Sensor always reads zero (or some other constant value).<\/a><\/li>\n<li><a href=\"\/til\/459\/\">Why don't I get a freefall acceleration value of 9.8 m\/s<sup>2<\/sup> when using a Motion Detector?<\/a><\/li>\n<li><a href=\"\/til\/2961\/\">How does a Vernier Motion Detector work (electrically)?<\/a><\/li>\n<li><a href=\"\/til\/1938\/\">Should I use a photogate or a Motion Detector?<\/a><\/li>\n<li><a href=\"\/til\/2053\/\">How do I improve the results from a Motion Detector with an air track?<\/a><\/li>\n<li><a href=\"\/til\/1036\/\">Will your Motion Detector show the speed of a (car, baseball, racquetball)?<\/a><\/li>\n<li><a href=\"\/til\/2426\/\">How do I attach the Motion Detector bracket to the Vernier track?<\/a><\/li>\n<li><a href=\"\/til\/2996\/\">Which motion detector should I buy?  What are the differences between them?<\/a><\/li>\n<li><a href=\"\/til\/3269\/\">Which Motion Detector model do I have?<\/a><\/li>\n<li><a href=\"\/til\/15786\/\">Go Direct sensor does not connect to LabQuest 2 via Bluetooth.<\/a><\/li>\n<li><a href=\"\/til\/4014\/\">How do I remove or replace a Go Direct battery?<\/a><\/li>\n<li><a href=\"\/til\/6827\/\">Troubleshooting Bluetooth Connections with Go Direct Sensors<\/a><\/li>\n<li><a href=\"\/til\/12943\/\">What can I do if a Go Direct sensor's Bluetooth LED flashes red and green when I try to connect to it and the connection fails?<\/a><\/li>\n<li><a href=\"\/til\/3857\/\">Will my device work with Go Direct Sensors via Bluetooth?<\/a><\/li>\n<li><a href=\"\/til\/3085\/\">How do I know if my LabQuest will work with Go Direct Sensors and Go Wireless devices?<\/a><\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<h3 class=\"wp-block-heading\">Specifications<\/h3>\n<ul class=\"wp-block-list\">\n<li>Range<br \/>\u26ac Motion and Motion with TC sensor channels: 0.25 m to 3.5 m<br \/>\u26ac Motion (cart) sensor channel: 0.15 m to 3.5 m<\/li>\n<li>Resolution: 1 mm<\/li>\n<li>Accuracy: 2 mm<\/li>\n<li>Temperature Compensation<br \/>\u26ac Motion with TC sensor channel only<br \/>\u26ac Internal temperature sensor responds to dynamic temperature changes<\/li>\n<li>Maximum sampling rate: 30 samples\/s<\/li>\n<li>Sensor dimensions:<br \/>\u26ac Length: 6.5 cm<br \/>\u26ac Width: 6.4 cm<br \/>\u26ac Height: 6.8 cm<\/li>\n<li>Ultrasound frequency: 50 kHz<\/li>\n<li>Power consumption: 51 mA<\/li>\n<li>Connections:<br \/>\u26ac Wireless: Bluetooth<sup>\u00ae<\/sup> v4.2 (wireless range 30 m unobstructed) <br \/>\u26ac Wired: USB 2.0 full speed<\/li>\n<li>Battery: <a href=\"https:\/\/www.vernier.com\/product\/go-direct-650-mah-replacement-battery\/\">650 mAh Li-Poly<\/a><br \/>\u26ac Battery Life (single, full charge): ~24 hours continuous data collection<br \/>\u26ac Battery Life (lifetime): 2 \u2013 5 years (typical)<\/li>\n<\/ul>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<h3 class=\"wp-block-heading\">Calibration<\/h3>\n<p class=\"wp-block-paragraph\">The default <strong>Motion<\/strong> sensor channel and the <strong>Motion (cart)<\/strong> sensor channel are factory calibrated and generally don&#8217;t require calibration. For better accuracy, you can calibrate these sensor channels by placing the front surface of the sensor a known (measured) distance from a flat object\/surface such as a book, box, or wall and performing a one-point calibration. For more information, see <a href=\"\/til\/2972\/\">Is there a way to calibrate a Motion Detector?<\/a>.<\/p>\n<p class=\"wp-block-paragraph\">The <strong>Motion with TC<\/strong> sensor channel uses an internal temperature sensor to determine the speed of sound to be used in calculations. This sensor channel cannot be calibrated.<\/p>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<h3 class=\"wp-block-heading\">Battery Troubleshooting<\/h3>\n<ol class=\"wp-block-list\">\n<li><span style=\"font-weight: 400;\">If the sensor can be turned on when connected by USB but not when disconnected from USB, the battery likely needs charging. <\/span><br \/>\u26ac <span style=\"font-weight: 400;\">Charge the sensor for several hours and try again. <\/span><\/li>\n<li><span style=\"font-weight: 400;\">If the sensor shows fully charged but still won&#8217;t turn on when connected via USB, then the battery has likely disconnected. <\/span><br \/>\u26ac <span style=\"font-weight: 400;\">Check the battery connection.<\/span><\/li>\n<li><span style=\"font-weight: 400;\">If the sensor still won\u2019t turn on, try swapping the battery with a working sensor to see if the problem follows the battery or stays with the sensor.<\/span><br \/>\u26ac If the problem stays with the sensor, the battery is probably not the issue.<br \/>\u26ac If the problem follows the battery, <span style=\"font-weight: 400;\">the battery has likely reached its end of life.<\/span><\/li>\n<li><span style=\"font-weight: 400;\">If the battery is indeed at the end of its life, the sensor cannot be used even if connected by USB, so the battery will need to be replaced. <\/span><span style=\"font-weight: 400;\"><a href=\"\/product\/go-direct-650-mah-replacement-battery\/\">Go Direct&reg; 650 mAh Replacement Battery<\/a> (<nobr>GDX-BAT-650<\/nobr>)<\/span><\/li>\n<li>See <a href=\"\/til\/4014\/\">How do I remove or replace a Go Direct battery?<\/a> for more information (including a <a href=\"https:\/\/youtu.be\/_NTHSD68ABE\">video<\/a>).<\/li>\n<\/ol>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<p class=\"has-text-align-center has-very-light-gray-background-color has-background wp-block-paragraph\"><span style=\"font-weight: 400;\"><strong>Rechargeable batteries are covered by a one-year warranty.<\/strong><\/span><br \/>Batteries <span style=\"font-weight: 400;\">should last two to five years in typical use. <\/span><\/p>\n<div style=\"height:20px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n<div class=\"wp-block-columns is-layout-flex wp-container-core-columns-is-layout-8f761849 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h3 class=\"wp-block-heading\">Related Products<\/h3>\n<ul class=\"wp-block-list\">\n<li><a href=\"\/product\/micro-usb-to-usb-c-cable\/\">Micro USB to USB-C Cable<\/a> (<nobr>CB-USB-C-MICRO<\/nobr>)<\/li>\n<li><a href=\"\/product\/go-direct-charge-station\/\">Go Direct<sup>&reg;<\/sup> Charge Station<\/a> (<nobr>GDX-CRG<\/nobr>)<\/li>\n<li><a href=\"\/product\/motion-detector-clamp\/\">Motion Detector Clamp<\/a> (<nobr>MD-CLAMP<\/nobr>)<\/li>\n<li><a href=\"\/product\/motion-detector-bracket\/\">Motion Detector Bracket<\/a> (<nobr>DTS-MDB<\/nobr>)<\/li>\n<li><a href=\"\/product\/motion-detector\/\">Motion Detector<\/a> (<nobr>MD-BTD<\/nobr>)<\/li>\n<li><a href=\"\/product\/cbr-2\/\">CBR 2<\/a> (<nobr>CBR2<\/nobr>)<\/li>\n<li><a href=\"\/product\/gomotion\/\">Go! Motion<\/a> (<nobr>GO-MOT<\/nobr>)<\/li>\n<\/ul>\n<\/div>\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\">\n<h3 class=\"wp-block-heading\">Replacement Parts<\/h3>\n<ul class=\"wp-block-list\">\n<li><a href=\"\/product\/go-direct-650-mah-replacement-battery\/\">Go Direct&reg; 650 mAh Replacement Battery<\/a> (<nobr>GDX-BAT-650<\/nobr>)<\/li>\n<li><a href=\"\/product\/micro-usb-cable\/\">Micro USB Cable<\/a> (<nobr>CB-USB-MICRO<\/nobr>)<\/li>\n<\/ul>\n<\/div>\n<\/div>","protected":false},"excerpt":{"rendered":"<p>Troubleshooting Press the power button on the sensor to turn it on. Connect your sensor as described in the Getting Started instructions for your device&#8230;.<\/p>\n","protected":false},"author":43901,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[922,7680,6926,6924,720,407,6927],"class_list":["post-4112","post","type-post","status-publish","format-standard","hentry","tag-gdx-md","tag-gdx-mdmain","tag-gdxmdmain-gdx-md-maintil","tag-graphical-analysis-motion","tag-maintil","tag-motion","tag-wireless-motion-detector"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/4112","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/users\/43901"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/comments?post=4112"}],"version-history":[{"count":0,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/4112\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/media?parent=4112"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/categories?post=4112"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/tags?post=4112"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}