{"action":"created","issue":{"url":"https://api.github.com/repos/Smoothieware/Smoothieware/issues/894","repository_url":"https://api.github.com/repos/Smoothieware/Smoothieware","labels_url":"https://api.github.com/repos/Smoothieware/Smoothieware/issues/894/labels{/name}","comments_url":"https://api.github.com/repos/Smoothieware/Smoothieware/issues/894/comments","events_url":"https://api.github.com/repos/Smoothieware/Smoothieware/issues/894/events","html_url":"https://github.com/Smoothieware/Smoothieware/issues/894","id":144949328,"number":894,"title":"max31855: potential fire hazard","user":{"login":"greyltc","id":16778174,"avatar_url":"https://avatars.githubusercontent.com/u/16778174?v=3","gravatar_id":"","url":"https://api.github.com/users/greyltc","html_url":"https://github.com/greyltc","followers_url":"https://api.github.com/users/greyltc/followers","following_url":"https://api.github.com/users/greyltc/following{/other_user}","gists_url":"https://api.github.com/users/greyltc/gists{/gist_id}","starred_url":"https://api.github.com/users/greyltc/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/greyltc/subscriptions","organizations_url":"https://api.github.com/users/greyltc/orgs","repos_url":"https://api.github.com/users/greyltc/repos","events_url":"https://api.github.com/users/greyltc/events{/privacy}","received_events_url":"https://api.github.com/users/greyltc/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":1,"created_at":"2016-03-31T16:25:27Z","updated_at":"2016-03-31T16:35:44Z","closed_at":null,"body":"Maybe the issue title is an over reaction, maybe not, but [these lines](https://github.com/Smoothieware/Smoothieware/blob/edge/src/modules/tools/temperaturecontrol/max31855.cpp#L69-L73) especially when taken in conjunction with [these other lines](https://github.com/Smoothieware/Smoothieware/blob/edge/src/modules/tools/temperaturecontrol/max31855.cpp#L99-L104) seem to me to mean that thermocouple temperature measurement errors get silently ignored.\r\n\r\nIn real life, this means if your thermocouple becomes disconnected/open circuit (a very real possibility when you're heating things that are also moving) when you're by chance in a heating cycle, then your heater will run continuously. That's a fire hazard.\r\n\r\nWe should do our very best to consider all the potential (temperature measurement) failure modes the firmware can possibly detect and make sure they result in the heaters being shut off."},"comment":{"url":"https://api.github.com/repos/Smoothieware/Smoothieware/issues/comments/204012069","html_url":"https://github.com/Smoothieware/Smoothieware/issues/894#issuecomment-204012069","issue_url":"https://api.github.com/repos/Smoothieware/Smoothieware/issues/894","id":204012069,"user":{"login":"greyltc","id":16778174,"avatar_url":"https://avatars.githubusercontent.com/u/16778174?v=3","gravatar_id":"","url":"https://api.github.com/users/greyltc","html_url":"https://github.com/greyltc","followers_url":"https://api.github.com/users/greyltc/followers","following_url":"https://api.github.com/users/greyltc/following{/other_user}","gists_url":"https://api.github.com/users/greyltc/gists{/gist_id}","starred_url":"https://api.github.com/users/greyltc/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/greyltc/subscriptions","organizations_url":"https://api.github.com/users/greyltc/orgs","repos_url":"https://api.github.com/users/greyltc/repos","events_url":"https://api.github.com/users/greyltc/events{/privacy}","received_events_url":"https://api.github.com/users/greyltc/received_events","type":"User","site_admin":false},"created_at":"2016-03-31T16:35:44Z","updated_at":"2016-03-31T16:35:44Z","body":"@hakalan, do you agree with my analysis here? or am I missing something?\r\nWhen I unplug my thermocouple while using the latest released firmware.bin my temperature readings are frozen to the last value measured, so something clearly needs to change. I hope https://github.com/Smoothieware/Smoothieware/pull/895 fixes it. It will mean the ring buffer will get \"poisoned\" by an inf value whenever there is a read error. Why and how often were you seeing read errors?"}}