> For the complete documentation index, see [llms.txt](https://agopengps.gitbook.io/agopengps/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://agopengps.gitbook.io/agopengps/starters-guide/what-to-buy/imu-inertial-measurement-unit.md).

# IMU (inertial measurement unit)

The IMU's job is to assist with orientation, pitch and roll. It helps immensely with accuracy in a single-GPS configuration, so much that you could say it is mandatory, but it's not needed if you're going dual-GPS. You can use it in dual as well tho, it won't hurt.

The BNO085 is the one to go for - no other is as good. The Adafruit is popular, but if you look at any kind of alternative, the pins have to be in the same configuration - so play it safe and stick with this. These can be hard to find, so watch the Discourse or Telegram channels as helpful members often post when they see stock at $VENDOR.

![](/files/uyuvQ3uPX8iryV2NVaSF)

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