Getting GOOD energy diagnostics for your iDevice

There's a lot of misinformation about power usage of iDevices out there, but a dearth of actual information and diagnostics tools.

The folks at the Apple Genius Bar seem have very good insight into your device, but unfortunately, the tools they use there are not publicly available.

Until now...

What's this project?

This toolset is based on Christopher Anderson's excellent work on emulating a Genius Bar WiFi network and getting your phone to upload its diagnostics information to your computer. He wrote a mitmproxy script that I've shamelessly reproduced here so you don't have to go hunting for it, but all the original work is his.

I'm adding tools to make sense of the bigass raw data dump that you're getting from your phone. Graphs work a lot better for human consumpation than big text files :).

The end result is something like this (and a bunch more graphs):

Notes

Currently, this script has only been tested on iOS 7. It seems that iOS 8 may have a different format for the powerlog. Pull requests are welcome.

Prerequisites

• Python
• mitmproxy
• gnuplot

Warning: I've taken no effort to make this work under Windows. If you want to go that route, good luck, let me know how it goes.

Grabbing the data

Original Blog Post

The steps are as follows:

• Install mitmproxy on your PC
• Edit capture.py and change the iPhone model number to match your actual device's.
• Run mitmdump -e -s capture.py
• Set mitmproxy as WiFi proxy on your iDevice
• Visit http://mitm.it/ from your iDevice and install the CA
• Visit diags:// on your iDevice, enter 123456 as ticket number and select Extended Diagnostics.

Done! You'll have two .tar.gz files in the script's working directory. Extract them, and especially for the powerlog, extract the files in there.

Plotting the data

Run graph.py on all your powerlog files:

python graph.py PLArchive/*.powerlog | gnuplot

(Note: on Windows the above will most certainly not work and you'll need to run the script on individual files)

gnuplot will create a bunch of .png files in the current directory.

Ta-daaah!!