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I'm trying to measure the energy usage level from my ipod when I run my application. I import the data from my device to Instruments app and the Energy usage level displays a bar graph. However, in the detail pane of Instruments the energy usage level don't show any number that indicate the level of energy used by the app in my device. Do you know how to get this energy usage level? I'm followed the steps stated in the Instruments Documentation to get the Energy Usage report from the iOS device; My iOS device is an ipod touch 3G and I'm using Xcode 3.0. Thanks!

airin
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You have to disconnect your device first, test your app, and reconnect. In instrument, select ->File ->Import Energy diagnostic From Device

It's not accurate anyway, I wonder how to translate from energy level (0-20) to real unit.

north212
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  • I did look up instruments guide to check what does energy level as a fraction of 20 represent, its just mentioned as Relative energy usage on a scale of 0-20. [Link](https://developer.apple.com/library/ios/documentation/AnalysisTools/Reference/Instruments_User_Reference/EnergyUsageInstrument/EnergyUsageInstrument.html) – Tejasvi Manmatha Dec 05 '13 at 16:13
  • In order to import an energy log you have to first go to the developer section of your settings, select instruments>untethered recording, and turn on the switch for energy, the press the "start recording" button. Let it run for a while, then go back and turn it off. Finally, go import the recording as you described. – Duncan C Jan 31 '14 at 15:43
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While you Energy Usage is selected from left hand Instruments list, from your menu select View -> Detail , or command + D for shortcut. You would then see detail view with Energy Usage Level.

Or

Move your inspection head to see Energy usage level Inspection Head in Instruments

Also note that in your device settings -> Developer -> Energy diagnostics Logging (On/Off switch), turning this switch off would reset previous logs.

0x8badf00d
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  • Hi, thanks for your answer. My problem is that although I followed the steps given by apple to log the energy usage I didn't get any energy level from my app. When I import the data from the iOS device, all the instruments (CPU Activity, sleep/awake, etc) give me some measurements, but Energy Usage instrument don't show anything. Do you know why it could happen? – airin Apr 05 '12 at 16:01
  • @airin Not sure why it doesn't show in Instrument. "Note: The Energy Usage instrument is currently supported in the iPhone 3GS and the third-generation iPod touch." Device you have said to be using is supported. Have you done one of these "1)Turn off power logging on the device. 2)Disconnect the device and reboot. 3)Drain the battery." ? – 0x8badf00d Apr 05 '12 at 20:43
  • Thanks for your response. I'm using an iPod third generation. I tried the options that you gave me but I still don't obtain any energy level . Which configuration (Xcode version, iOS version, device, etc) did you use when you got the results in the above figure? – airin Apr 06 '12 at 21:58
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    Based on the testing I just did, it looks like your device won't sleep when it is tethered and instruments is running. It seems that for background/sleep energy monitoring, you'll get a more realistic view if you turn on untethered monitoring, capture a log, then open and view THAT in instruments. – Duncan C Jan 31 '14 at 15:44
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Energy Diagnostics has other problems, namely it lacks granularity and isn't always accurate. My company wrote Powergremlin to solve those problems and, while very simple, you might find it useful.

Drew Stephens
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Finally I found a solution. I was using an ipod labeled as 3rd generation but as it didn't work I decided to try with an iPhone 3GS and it works, the energy level usage is shown in Instruments.

airin
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