{"action":"created","issue":{"url":"https://api.github.com/repos/roboterclubaachen/xpcc/issues/127","repository_url":"https://api.github.com/repos/roboterclubaachen/xpcc","labels_url":"https://api.github.com/repos/roboterclubaachen/xpcc/issues/127/labels{/name}","comments_url":"https://api.github.com/repos/roboterclubaachen/xpcc/issues/127/comments","events_url":"https://api.github.com/repos/roboterclubaachen/xpcc/issues/127/events","html_url":"https://github.com/roboterclubaachen/xpcc/issues/127","id":154900708,"number":127,"title":"STM32F103 I2C: When reading exactly two bytes the first byte is not acknowledged by the I2C master.","user":{"login":"strongly-typed","id":1626990,"avatar_url":"https://avatars.githubusercontent.com/u/1626990?v=3","gravatar_id":"","url":"https://api.github.com/users/strongly-typed","html_url":"https://github.com/strongly-typed","followers_url":"https://api.github.com/users/strongly-typed/followers","following_url":"https://api.github.com/users/strongly-typed/following{/other_user}","gists_url":"https://api.github.com/users/strongly-typed/gists{/gist_id}","starred_url":"https://api.github.com/users/strongly-typed/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/strongly-typed/subscriptions","organizations_url":"https://api.github.com/users/strongly-typed/orgs","repos_url":"https://api.github.com/users/strongly-typed/repos","events_url":"https://api.github.com/users/strongly-typed/events{/privacy}","received_events_url":"https://api.github.com/users/strongly-typed/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/roboterclubaachen/xpcc/labels/bug","name":"bug","color":"fc2929"},{"url":"https://api.github.com/repos/roboterclubaachen/xpcc/labels/cortex-m","name":"cortex-m","color":"fef2c0"},{"url":"https://api.github.com/repos/roboterclubaachen/xpcc/labels/io","name":"io","color":"bfd4f2"},{"url":"https://api.github.com/repos/roboterclubaachen/xpcc/labels/stm32","name":"stm32","color":"fef2c0"}],"state":"open","locked":false,"assignee":{"login":"salkinium","id":163066,"avatar_url":"https://avatars.githubusercontent.com/u/163066?v=3","gravatar_id":"","url":"https://api.github.com/users/salkinium","html_url":"https://github.com/salkinium","followers_url":"https://api.github.com/users/salkinium/followers","following_url":"https://api.github.com/users/salkinium/following{/other_user}","gists_url":"https://api.github.com/users/salkinium/gists{/gist_id}","starred_url":"https://api.github.com/users/salkinium/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/salkinium/subscriptions","organizations_url":"https://api.github.com/users/salkinium/orgs","repos_url":"https://api.github.com/users/salkinium/repos","events_url":"https://api.github.com/users/salkinium/events{/privacy}","received_events_url":"https://api.github.com/users/salkinium/received_events","type":"User","site_admin":false},"milestone":null,"comments":1,"created_at":"2016-05-15T10:08:13Z","updated_at":"2016-05-15T12:23:26Z","closed_at":null,"body":"I stumbled over a coarse resolution of the `BMP180` sensor connected to an `STM32F103C8T6` at `I2cMaster1`. When reading exactly two bytes the first byte is not acknowledged by the master so that the slave will not send its second byte. The value is then always `0xff` and that resulted in a coarse temperature resolution.\r\n\r\nNevertheless the transaction returns `true`.\r\n\r\n     this->transaction.configureWriteRead(buffer, 1, data.raw, 2);\r\n<img width=\"1001\" alt=\"screen shot 2016-05-15 at 11 55 16\" src=\"https://cloud.githubusercontent.com/assets/1626990/15273294/39918a8c-1a94-11e6-9036-a04fe036b93f.png\">\r\n\r\nWhen reading three or more bytes the first data read is acknowledged.\r\n\r\n     this->transaction.configureWriteRead(buffer, 1, data.raw, 3);\r\n<img width=\"1160\" alt=\"screen shot 2016-05-15 at 11 53 58\" src=\"https://cloud.githubusercontent.com/assets/1626990/15273297/4145d26a-1a94-11e6-9b31-7581310ac5b2.png\">\r\n\r\nWith an `STM32F407` discovery board the two bytes read works correctly:\r\n<img width=\"811\" alt=\"screen shot 2016-05-15 at 12 19 12\" src=\"https://cloud.githubusercontent.com/assets/1626990/15273365/5f6909a8-1a97-11e6-9932-9b91ae498aee.png\">\r\n"},"comment":{"url":"https://api.github.com/repos/roboterclubaachen/xpcc/issues/comments/219282783","html_url":"https://github.com/roboterclubaachen/xpcc/issues/127#issuecomment-219282783","issue_url":"https://api.github.com/repos/roboterclubaachen/xpcc/issues/127","id":219282783,"user":{"login":"salkinium","id":163066,"avatar_url":"https://avatars.githubusercontent.com/u/163066?v=3","gravatar_id":"","url":"https://api.github.com/users/salkinium","html_url":"https://github.com/salkinium","followers_url":"https://api.github.com/users/salkinium/followers","following_url":"https://api.github.com/users/salkinium/following{/other_user}","gists_url":"https://api.github.com/users/salkinium/gists{/gist_id}","starred_url":"https://api.github.com/users/salkinium/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/salkinium/subscriptions","organizations_url":"https://api.github.com/users/salkinium/orgs","repos_url":"https://api.github.com/users/salkinium/repos","events_url":"https://api.github.com/users/salkinium/events{/privacy}","received_events_url":"https://api.github.com/users/salkinium/received_events","type":"User","site_admin":false},"created_at":"2016-05-15T12:23:26Z","updated_at":"2016-05-15T12:23:26Z","body":"The reference manual between F1 and F4 is identical EXCEPT in _drumroll_ 2B I2C Master Reception.\r\nI hate ST so much right now."}}