{"action":"created","comment":{"url":"https://api.github.com/repos/betaflight/betaflight/pulls/comments/180089650","pull_request_review_id":110448237,"id":180089650,"diff_hunk":"@@ -102,14 +102,45 @@ If you're using an OSD that expects the multiwii current meter output value, the\n \n ### ADC Sensor\n \n-The current meter may need to be configured so the value read at the ADC input matches actual current draw.  Just like you need a voltmeter to correctly calibrate your voltage reading you also need an ammeter to calibrate the current sensor.\n+The current meter needs to be configured so the value read at the Analog to Digital Converter (ADC) input matches actual current draw.  Just like you need a voltmeter to correctly calibrate your voltage reading you also need an ammeter to calibrate the current sensor.\n+Unlike voltage sensing which is usually quite good from the factory, current sensing varies significantly from board to board and should be calibrated.\n \n-Use the following settings to adjust calibration:\n+It is recommended to set `multiwii_amperage_meter_output` to `OFF` when calibrating ADC current sensor.\n \n-`amperage_meter_scale`\n-`amperage_meter_offset`\n+To measure the current a linear response device is used that converts the current traveling through it to a voltage to be read by the ADC on your flight controller.\n+The maximum voltage that the flight controller can read is 3.3V (3300 mV), this is usually the limiting factor on the maximum measurable current.\n+Most sensors use a shunt resistor to measure current however there are a few that use hall effect sensors.\n \n-It is recommended to set `multiwii_amperage_meter_output` to `OFF` when calibrating ADC current sensor.\n+The flight controller uses the following equation to convert the measured ADC voltage to a current.\n+```\n+Current(Amps) = ADC (mV) / amperage_meter_scale * 10 + amperage_meter_offset / 1000\n+```\n+Where the calibrations are:\n+\n+| Setting                       | Description                                              |\n+| ----------------------------- | -------------------------------------------------------- | \n+| `amperage_meter_scale`     | The scaling factor in mV/10A  |\n+| `amperage_meter_offset`    | The offset in mA |\n+\n+This is in the mathematical form of y = x/m + b and with a few measurements along this line you can calibrate any combination of sensor and flight controller to a high accuracy.\n+\n+#### Calibrate using an ammeter\n+\n+**!!Important: Always take off your props before doing any testing!!**\n+\n+To calibrate your flight controller with a current meter follow these steps.\n+\n+1. Make a copy of [this google sheet](https://docs.google.com/spreadsheets/d/1lkL-X_FT9x2oqrwQEctDsEUhgdY19upNGc78M6FfJXY/). It will do all of the maths for you.","path":"docs/Battery.md","position":45,"original_position":45,"commit_id":"e31098b18bde57f9a48a354af339e433cb9bba57","original_commit_id":"e31098b18bde57f9a48a354af339e433cb9bba57","user":{"login":"mikeller","id":4742747,"avatar_url":"https://avatars1.githubusercontent.com/u/4742747?v=4","gravatar_id":"","url":"https://api.github.com/users/mikeller","html_url":"https://github.com/mikeller","followers_url":"https://api.github.com/users/mikeller/followers","following_url":"https://api.github.com/users/mikeller/following{/other_user}","gists_url":"https://api.github.com/users/mikeller/gists{/gist_id}","starred_url":"https://api.github.com/users/mikeller/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mikeller/subscriptions","organizations_url":"https://api.github.com/users/mikeller/orgs","repos_url":"https://api.github.com/users/mikeller/repos","events_url":"https://api.github.com/users/mikeller/events{/privacy}","received_events_url":"https://api.github.com/users/mikeller/received_events","type":"User","site_admin":false},"body":"Ok. Then we should point that out in the text so it becomes clear to users without having to look at the spreadsheet.","created_at":"2018-04-09T13:14:57Z","updated_at":"2018-04-09T13:14:57Z","html_url":"https://github.com/betaflight/betaflight/pull/5658#discussion_r180089650","pull_request_url":"https://api.github.com/repos/betaflight/betaflight/pulls/5658","author_association":"OWNER","_links":{"self":{"href":"https://api.github.com/repos/betaflight/betaflight/pulls/comments/180089650"},"html":{"href":"https://github.com/betaflight/betaflight/pull/5658#discussion_r180089650"},"pull_request":{"href":"https://api.github.com/repos/betaflight/betaflight/pulls/5658"}},"in_reply_to_id":180084254},"pull_request":{"url":"https://api.github.com/repos/betaflight/betaflight/pulls/5658","id":180296532,"html_url":"https://github.com/betaflight/betaflight/pull/5658","diff_url":"https://github.com/betaflight/betaflight/pull/5658.diff","patch_url":"https://github.com/betaflight/betaflight/pull/5658.patch","issue_url":"https://api.github.com/repos/betaflight/betaflight/issues/5658","number":5658,"state":"open","locked":false,"title":"New readme for calibrating current sensors","user":{"login":"Dimand","id":1551981,"avatar_url":"https://avatars0.githubusercontent.com/u/1551981?v=4","gravatar_id":"","url":"https://api.github.com/users/Dimand","html_url":"https://github.com/Dimand","followers_url":"https://api.github.com/users/Dimand/followers","following_url":"https://api.github.com/users/Dimand/following{/other_user}","gists_url":"https://api.github.com/users/Dimand/gists{/gist_id}","starred_url":"https://api.github.com/users/Dimand/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Dimand/subscriptions","organizations_url":"https://api.github.com/users/Dimand/orgs","repos_url":"https://api.github.com/users/Dimand/repos","events_url":"https://api.github.com/users/Dimand/events{/privacy}","received_events_url":"https://api.github.com/users/Dimand/received_events","type":"User","site_admin":false},"body":"Updating with current calibration process as requested in #5614.\r\nThis updates the method to be in line with the changes implemented in #4743.\r\n\r\nI still want to make a video but that will take some 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