{"action":"created","issue":{"url":"https://api.github.com/repos/esp8266/Arduino/issues/338","labels_url":"https://api.github.com/repos/esp8266/Arduino/issues/338/labels{/name}","comments_url":"https://api.github.com/repos/esp8266/Arduino/issues/338/comments","events_url":"https://api.github.com/repos/esp8266/Arduino/issues/338/events","html_url":"https://github.com/esp8266/Arduino/issues/338","id":80997205,"number":338,"title":"Using ADC ","user":{"login":"fchanson","id":11351781,"avatar_url":"https://avatars.githubusercontent.com/u/11351781?v=3","gravatar_id":"","url":"https://api.github.com/users/fchanson","html_url":"https://github.com/fchanson","followers_url":"https://api.github.com/users/fchanson/followers","following_url":"https://api.github.com/users/fchanson/following{/other_user}","gists_url":"https://api.github.com/users/fchanson/gists{/gist_id}","starred_url":"https://api.github.com/users/fchanson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/fchanson/subscriptions","organizations_url":"https://api.github.com/users/fchanson/orgs","repos_url":"https://api.github.com/users/fchanson/repos","events_url":"https://api.github.com/users/fchanson/events{/privacy}","received_events_url":"https://api.github.com/users/fchanson/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":12,"created_at":"2015-05-26T14:49:31Z","updated_at":"2015-06-02T14:58:39Z","closed_at":null,"body":"Hi,\r\n\r\nI made some tests on the ADC using a NodeMCU 0.9.5 build 20150318.\r\nMy code just reads the value on the pin every 500ms.\r\n\r\nUsing a Arduino program : \r\n- pin A0 at GND --> analogRead(A0) = 700\r\n- pin A0 at 3.3V --> analogRead(A0) = 909\r\n\r\nI am surprised to have the value 700 when voltage on pin A0 is GND. Should be near 0.\r\n\r\n\r\nI made the same test with a LUA program using ESPlorer.\r\nThe result is the following :\r\n- pin A0 at GND --> adc.read(0) = 4\r\n- pin A0 at 3.3V --> adc.read(0) = 1023\r\n\r\nThese last results sound good.\r\n\r\n\r\nDoes anyone have the same problem ?\r\n\r\nNeed something special to use the ADC pin ?\r\n\r\nThanks."},"comment":{"url":"https://api.github.com/repos/esp8266/Arduino/issues/comments/107983734","html_url":"https://github.com/esp8266/Arduino/issues/338#issuecomment-107983734","issue_url":"https://api.github.com/repos/esp8266/Arduino/issues/338","id":107983734,"user":{"login":"bluewalk","id":6522477,"avatar_url":"https://avatars.githubusercontent.com/u/6522477?v=3","gravatar_id":"","url":"https://api.github.com/users/bluewalk","html_url":"https://github.com/bluewalk","followers_url":"https://api.github.com/users/bluewalk/followers","following_url":"https://api.github.com/users/bluewalk/following{/other_user}","gists_url":"https://api.github.com/users/bluewalk/gists{/gist_id}","starred_url":"https://api.github.com/users/bluewalk/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/bluewalk/subscriptions","organizations_url":"https://api.github.com/users/bluewalk/orgs","repos_url":"https://api.github.com/users/bluewalk/repos","events_url":"https://api.github.com/users/bluewalk/events{/privacy}","received_events_url":"https://api.github.com/users/bluewalk/received_events","type":"User","site_admin":false},"created_at":"2015-06-02T14:58:39Z","updated_at":"2015-06-02T14:58:39Z","body":"Yes, I'm using the following schematic: \r\n![adc_nodemcuboard](https://cloud.githubusercontent.com/assets/6522477/7938925/77148610-0948-11e5-99aa-bd4d1405fc89.png)\r\nIt's part of the NodeMCU dev board. I'm also using this schematic in one of my own designed pcb's.\r\n"}}