The most convenient way to measure power is to use power consumption apps.
There are dozens to choose from, and they seem to provide reliable data in a nice package. However, there are some things you should be aware of, when using these apps.
Apps rule the world, there is no doubt about that. Every problem can be solved with an app, including how to measure power. There are many things were smartphones and apps excel, but there are also many things where smartphones and apps are not necessarily the best choice for the task at hand.
We put together an infographics about some issues with power consumption apps, check it out!
The solution for the issues is to use a dedicated measurement tool, which has high accuracy and high sample rate. By tapping into the main power rail for direct power measurement eliminates all the guesswork and no power consumption spikes are missed. The downside of this method is the need for hardware modification to gain access to the power rail.
We have done some comparisons between power measurements of apps vs. external power measurements. Depending on use case and device under test, the error can be anything from 5% to 200%. That is very unpredictable and unacceptable for many scenarios.
So if you need to measure power, remember to consider your options. If you want the the most accurate and reliable data, use a dedicated measurement tool. If you can’t do that yourself, you can always contact us. We may be able to help.