{"id":11802,"date":"2013-11-24T13:59:11","date_gmt":"2013-11-24T19:59:11","guid":{"rendered":"http:\/\/bucktownbell.com\/?p=11802"},"modified":"2013-11-24T13:59:11","modified_gmt":"2013-11-24T19:59:11","slug":"decoding-radio-controlled-bus-stop-displays","status":"publish","type":"post","link":"http:\/\/bucktownbell.com\/?p=11802","title":{"rendered":"Decoding radio-controlled bus stop displays"},"content":{"rendered":"<blockquote><p>I had the opportunity to observe a display stuck in the middle of its bootup sequence, displaying a version string. This revealed that the system is called IBus and it&#8217;s made by the Swedish company Axentia. Sure enough, their website talks about DARC and how it requires no return channel, making it possible to use battery-powered displays in remote areas.<\/p>\n<p>Not much else is said about the system, though; there are no specs for the proprietary protocol. So I implemented the five-layer DARC protocol stack in Perl and was left with a stream of fully error-corrected packets on top of Layer 5, separated into hundreds of subchannels. Some of these contained human-readable strings with names of terminal stations. They seemed like an easy starting point for reverse engineering.<\/p><\/blockquote>\n<p>via <a href=\"http:\/\/www.windytan.com\/2013\/11\/decoding-radio-controlled-bus-stop.html\">absorptions: Decoding radio-controlled bus stop displays<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I had the opportunity to observe a display stuck in the middle of its bootup sequence, displaying a version string. This revealed that the system is called IBus and it&#8217;s made by the Swedish company Axentia. Sure enough, their website &hellip; <a href=\"http:\/\/bucktownbell.com\/?p=11802\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[737],"tags":[102,171,570],"class_list":["post-11802","post","type-post","status-publish","format-standard","hentry","category-stem","tag-hacking","tag-perl","tag-sdr"],"_links":{"self":[{"href":"http:\/\/bucktownbell.com\/index.php?rest_route=\/wp\/v2\/posts\/11802","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/bucktownbell.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/bucktownbell.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/bucktownbell.com\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/bucktownbell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=11802"}],"version-history":[{"count":1,"href":"http:\/\/bucktownbell.com\/index.php?rest_route=\/wp\/v2\/posts\/11802\/revisions"}],"predecessor-version":[{"id":11803,"href":"http:\/\/bucktownbell.com\/index.php?rest_route=\/wp\/v2\/posts\/11802\/revisions\/11803"}],"wp:attachment":[{"href":"http:\/\/bucktownbell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=11802"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/bucktownbell.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=11802"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/bucktownbell.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=11802"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}