{"action":"created","issue":{"url":"https://api.github.com/repos/arduino/Arduino/issues/2687","labels_url":"https://api.github.com/repos/arduino/Arduino/issues/2687/labels{/name}","comments_url":"https://api.github.com/repos/arduino/Arduino/issues/2687/comments","events_url":"https://api.github.com/repos/arduino/Arduino/issues/2687/events","html_url":"https://github.com/arduino/Arduino/issues/2687","id":58770098,"number":2687,"title":"internal pullups on I2C","user":{"login":"cano64","id":4314367,"avatar_url":"https://avatars.githubusercontent.com/u/4314367?v=3","gravatar_id":"","url":"https://api.github.com/users/cano64","html_url":"https://github.com/cano64","followers_url":"https://api.github.com/users/cano64/followers","following_url":"https://api.github.com/users/cano64/following{/other_user}","gists_url":"https://api.github.com/users/cano64/gists{/gist_id}","starred_url":"https://api.github.com/users/cano64/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/cano64/subscriptions","organizations_url":"https://api.github.com/users/cano64/orgs","repos_url":"https://api.github.com/users/cano64/repos","events_url":"https://api.github.com/users/cano64/events{/privacy}","received_events_url":"https://api.github.com/users/cano64/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/arduino/Arduino/labels/Library:%20Wire","name":"Library: Wire","color":"000000"},{"url":"https://api.github.com/repos/arduino/Arduino/labels/Type:%20Duplicate","name":"Type: Duplicate","color":"f7c6c7"},{"url":"https://api.github.com/repos/arduino/Arduino/labels/Waiting%20for%20feedback","name":"Waiting for feedback","color":"fef2c0"}],"state":"closed","locked":false,"assignee":{"login":"cmaglie","id":423515,"avatar_url":"https://avatars.githubusercontent.com/u/423515?v=3","gravatar_id":"","url":"https://api.github.com/users/cmaglie","html_url":"https://github.com/cmaglie","followers_url":"https://api.github.com/users/cmaglie/followers","following_url":"https://api.github.com/users/cmaglie/following{/other_user}","gists_url":"https://api.github.com/users/cmaglie/gists{/gist_id}","starred_url":"https://api.github.com/users/cmaglie/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/cmaglie/subscriptions","organizations_url":"https://api.github.com/users/cmaglie/orgs","repos_url":"https://api.github.com/users/cmaglie/repos","events_url":"https://api.github.com/users/cmaglie/events{/privacy}","received_events_url":"https://api.github.com/users/cmaglie/received_events","type":"User","site_admin":false},"milestone":null,"comments":2,"created_at":"2015-02-24T17:13:48Z","updated_at":"2015-08-27T16:47:15Z","closed_at":"2015-08-27T16:47:15Z","body":"This is a serious bug, that may cause destruction of a hardware attached to I2C and has been known for many years, yet it has not been fixed.\r\n\r\nArduino/hardware/arduino/avr/libraries/Wire/utility/twi.c\r\nthose two lines needs to be commented out.\r\ndigitalWrite(SDA, 1);\r\ndigitalWrite(SCL, 1);\r\n\r\nIf one has a I2C device that is powered by 3.3V and is not 5V tolerant, using the current Wire library will cause 5V to be applied through the internal pullup resistors of the Atmel part to the I2C device, possibly destroying the device.\r\n\r\nsetting internal pullup resistors on I2C has absolutely no benefits whatsoever. Most I2C devices need pullup resistors of 4.7k-10k ohms, internal pullups are 20k ohms or higher and are no good for this purpose.\r\nIf one wishes to use internal pullups for some reason, they can set them manually in their sketch.\r\n"},"comment":{"url":"https://api.github.com/repos/arduino/Arduino/issues/comments/135489636","html_url":"https://github.com/arduino/Arduino/issues/2687#issuecomment-135489636","issue_url":"https://api.github.com/repos/arduino/Arduino/issues/2687","id":135489636,"user":{"login":"cmaglie","id":423515,"avatar_url":"https://avatars.githubusercontent.com/u/423515?v=3","gravatar_id":"","url":"https://api.github.com/users/cmaglie","html_url":"https://github.com/cmaglie","followers_url":"https://api.github.com/users/cmaglie/followers","following_url":"https://api.github.com/users/cmaglie/following{/other_user}","gists_url":"https://api.github.com/users/cmaglie/gists{/gist_id}","starred_url":"https://api.github.com/users/cmaglie/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/cmaglie/subscriptions","organizations_url":"https://api.github.com/users/cmaglie/orgs","repos_url":"https://api.github.com/users/cmaglie/repos","events_url":"https://api.github.com/users/cmaglie/events{/privacy}","received_events_url":"https://api.github.com/users/cmaglie/received_events","type":"User","site_admin":false},"created_at":"2015-08-27T16:47:15Z","updated_at":"2015-08-27T16:47:15Z","body":"Closing as duplicate of #506 "}}