{"action":"created","issue":{"url":"https://api.github.com/repos/iguanaworks/Test/issues/3","labels_url":"https://api.github.com/repos/iguanaworks/Test/issues/3/labels{/name}","comments_url":"https://api.github.com/repos/iguanaworks/Test/issues/3/comments","events_url":"https://api.github.com/repos/iguanaworks/Test/issues/3/events","html_url":"https://github.com/iguanaworks/Test/issues/3","id":53599549,"number":3,"title":"Duty cycle on sends not 50/50","user":{"login":"IguanaBen","id":8941130,"avatar_url":"https://avatars.githubusercontent.com/u/8941130?v=3","gravatar_id":"","url":"https://api.github.com/users/IguanaBen","html_url":"https://github.com/IguanaBen","followers_url":"https://api.github.com/users/IguanaBen/followers","following_url":"https://api.github.com/users/IguanaBen/following{/other_user}","gists_url":"https://api.github.com/users/IguanaBen/gists{/gist_id}","starred_url":"https://api.github.com/users/IguanaBen/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/IguanaBen/subscriptions","organizations_url":"https://api.github.com/users/IguanaBen/orgs","repos_url":"https://api.github.com/users/IguanaBen/repos","events_url":"https://api.github.com/users/IguanaBen/events{/privacy}","received_events_url":"https://api.github.com/users/IguanaBen/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":{"login":"jdunn14","id":8950097,"avatar_url":"https://avatars.githubusercontent.com/u/8950097?v=3","gravatar_id":"","url":"https://api.github.com/users/jdunn14","html_url":"https://github.com/jdunn14","followers_url":"https://api.github.com/users/jdunn14/followers","following_url":"https://api.github.com/users/jdunn14/following{/other_user}","gists_url":"https://api.github.com/users/jdunn14/gists{/gist_id}","starred_url":"https://api.github.com/users/jdunn14/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jdunn14/subscriptions","organizations_url":"https://api.github.com/users/jdunn14/orgs","repos_url":"https://api.github.com/users/jdunn14/repos","events_url":"https://api.github.com/users/jdunn14/events{/privacy}","received_events_url":"https://api.github.com/users/jdunn14/received_events","type":"User","site_admin":false},"milestone":null,"comments":3,"created_at":"2015-01-07T05:38:44Z","updated_at":"2015-01-07T05:38:49Z","closed_at":null,"body":"**Reported by bluey on 2 May 2008 22:36 UTC**\nThe duty cycle on IR sending is not exactly 50/50. This is because of an asymmetry between pulling the voltage on the LED to 5V vs pulling the voltage on the LED down to ground (and an asymmetry in the LED).\r\n\r\nAt 150kHz, the duty cycle is 60/40 (4us on, 2.66us off). This works out to having the LED on an extra 0.66us. The duty cycle is approximately\r\n\r\n``` 0.5+/- carrier_frequency*0.66us ```\r\n\r\nThis offset is clearly more significant at higher frequencies. At 38kHz, the duty cycle is 52.5 / 47.5 but it grows with freq to 60/40 at 150kHz. \r\n\r\nThis is not a problem since even a 60/40 duty cycle will work for most applications. Is we want to push to higher frequencies (why?) we might want to try to compensate for this offset in the firmware.\r\n\r\nThese measurements were made by measuring the current flowing through the LED. Attached is a graph of one cycle at 150kHz. 1V = 20mA\r\n"},"comment":{"url":"https://api.github.com/repos/iguanaworks/Test/issues/comments/68981222","html_url":"https://github.com/iguanaworks/Test/issues/3#issuecomment-68981222","issue_url":"https://api.github.com/repos/iguanaworks/Test/issues/3","id":68981222,"user":{"login":"IguanaBen","id":8941130,"avatar_url":"https://avatars.githubusercontent.com/u/8941130?v=3","gravatar_id":"","url":"https://api.github.com/users/IguanaBen","html_url":"https://github.com/IguanaBen","followers_url":"https://api.github.com/users/IguanaBen/followers","following_url":"https://api.github.com/users/IguanaBen/following{/other_user}","gists_url":"https://api.github.com/users/IguanaBen/gists{/gist_id}","starred_url":"https://api.github.com/users/IguanaBen/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/IguanaBen/subscriptions","organizations_url":"https://api.github.com/users/IguanaBen/orgs","repos_url":"https://api.github.com/users/IguanaBen/repos","events_url":"https://api.github.com/users/IguanaBen/events{/privacy}","received_events_url":"https://api.github.com/users/IguanaBen/received_events","type":"User","site_admin":false},"created_at":"2015-01-07T05:38:48Z","updated_at":"2015-01-07T05:38:48Z","body":"**Commented by bluey on 28 Mar 2012 15:29 UTC**\nTesting email notifications. Ignore."}}