{"id":186,"date":"2014-12-10T22:45:03","date_gmt":"2014-12-10T22:45:03","guid":{"rendered":"http:\/\/int03.co.uk\/blog\/?p=186"},"modified":"2014-12-13T21:44:02","modified_gmt":"2014-12-13T21:44:02","slug":"nvidia-3d-vision-pro-and-vesa-stereo-sync","status":"publish","type":"post","link":"https:\/\/int03.co.uk\/blog\/2014\/12\/10\/nvidia-3d-vision-pro-and-vesa-stereo-sync\/","title":{"rendered":"NVIDIA 3D Vision Pro and VESA Stereo Sync"},"content":{"rendered":"<p>We ran into problems recently getting the NVIDIA 3D Vision Pro glasses to work on a dual-pipe stereo projector (clone mode stereo).\u00a0The projector takes two DVI inputs, one for the left and one for the right eye at 1920&#215;1080 and 60Hz. These are then displayed frame sequentially at 120Hz. The projector has the standard BNC connector which outputs the stereo sync signal for the glasses (Sync and Ground).<\/p>\n<p>The NVIDIA RF base station (pyramid) has a 2.5mm stereo jack socket which accepts external stereo sync, so we tried feeding the projector sync into that input. Unfortunately, the pyramid seemed to ignore the external sync and wouldn&#8217;t\u00a0activate the glasses&#8230;<\/p>\n<p>We had the NVIDIA pyramid working well on another system\u00a0in active stereo, using the 3-pin VESA sync output from the graphics card, so I decided to test that.\u00a0This is what I found:<\/p>\n<ul>\n<li>When running at 120Hz active stereo, the Sync\u00a0signal is a simple 5V square wave with 50% duty cycle of around 8.33ms high and 8.33ms low, exactly as you would expect.<\/li>\n<li>The LED on the back of the pyramid lights up blue when it&#8217;s using external sync, green otherwise.<\/li>\n<li>When using active stereo, the Sync\u00a0light only illuminates when stereo is activated (i.e. when running a stereo application)<\/li>\n<li>5V power is always present on the 3-pin VESA stereo connector.<\/li>\n<li><strong>If the 5V power is removed, it ignores the external SYNC input. Using only SYNC and GND is not enough to get it working.<\/strong><\/li>\n<li>Once it has switched on and started accepting external Sync, I tried disconnecting the 5V power: the blue LED stayed lit. This suggests it only checks for presence of 5V at start up.<\/li>\n<\/ul>\n<p>This is what the Sync\u00a0LED\u00a0looks like when the unit is persuaded to accept\u00a0external sync:<\/p>\n<p style=\"text-align: justify;\"><a href=\"http:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvida_pro_sync.jpg\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-187\" src=\"http:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvida_pro_sync-300x225.jpg\" alt=\"NVIDIA 3D Vision Pro Pyramid\" width=\"300\" height=\"225\" srcset=\"https:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvida_pro_sync-300x225.jpg 300w, https:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvida_pro_sync.jpg 640w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/a><\/p>\n<p style=\"text-align: justify;\">The solution was to make a cable which combines the Sync output from the projector with 5V (taken from USB) and Ground onto a standard 3-pin mini DIN VESA stereo connector (pinout shown below). The picture above shows the cable (white Y-shaped cable) taking Sync via a BNC connector (the T-piece is used to connect another IR emitter in parallel) and the connectors on the right are the 3-pin mini DIN stereo cable, which goes to the 2.5mm jack sync input on the NVIDIA pyramid.<\/p>\n<p style=\"text-align: justify;\">This is the pinout\u00a0of the VESA Stereo 3-pin mini-DIN socket:<\/p>\n<p style=\"text-align: justify;\">\u00a0<img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-191\" src=\"http:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/stereo_3_pin_DIN-300x163.png\" alt=\"VESA Stereo 3-pin DIN\" width=\"300\" height=\"163\" srcset=\"https:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/stereo_3_pin_DIN-300x163.png 300w, https:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/stereo_3_pin_DIN.png 642w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p style=\"text-align: justify;\">\u00a0And here&#8217;s the corresponding pinout for the NVIDA 3D sync jack:<\/p>\n<p style=\"text-align: justify;\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-medium wp-image-193\" src=\"http:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvidia_3d_sync_jack-300x88.png\" alt=\"NVIDIA 3D Sync Jack Plug\" width=\"300\" height=\"88\" srcset=\"https:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvidia_3d_sync_jack-300x88.png 300w, https:\/\/int03.co.uk\/blog\/wp-content\/uploads\/2014\/12\/nvidia_3d_sync_jack.png 889w\" sizes=\"(max-width: 300px) 100vw, 300px\" \/><\/p>\n<p style=\"text-align: justify;\">Caution: the jack plug isn&#8217;t a great choice of connector for something carrying GND and 5V, as there is obvious potential for a temporary short when the plug slides in and out of the socket. Avoid connecting\/disconnecting the jack when the system is powered up. It&#8217;s safer to disconnect the USB and mini-DIN plugs.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>We ran into problems recently getting the NVIDIA 3D Vision Pro glasses to work on a dual-pipe stereo projector (clone mode stereo).\u00a0The projector takes two DVI inputs, one for the left and one for the right eye at 1920&#215;1080 and 60Hz. These are then displayed frame sequentially at 120Hz. The projector has the standard BNC &hellip; <a href=\"https:\/\/int03.co.uk\/blog\/2014\/12\/10\/nvidia-3d-vision-pro-and-vesa-stereo-sync\/\" class=\"more-link\">Continue reading <span class=\"screen-reader-text\">NVIDIA 3D Vision Pro and VESA Stereo Sync<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"_links":{"self":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts\/186"}],"collection":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/comments?post=186"}],"version-history":[{"count":6,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts\/186\/revisions"}],"predecessor-version":[{"id":209,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/posts\/186\/revisions\/209"}],"wp:attachment":[{"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/media?parent=186"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/categories?post=186"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/int03.co.uk\/blog\/wp-json\/wp\/v2\/tags?post=186"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}