Would it be possible to use only external gps/compass and disable all internal gyro/imu?

Rover uses the same EKF fusion of sensors as Copter and Plane. You need them.
Based on your question do you need a flight controller at all for your application? Easy enough to drive a Rover w/o one.

It totally makes sense that copter and plane would need an IMU. But its harder for me to understand why it would be necessary for rover? Maybe you can help me understand better? Is it just that thats how ardupilot is built and there is no way to easily disable the IMU? Not that it would actually be required for an autonomous rover to operate?

Lol thats a funny comment about needing a flight controller at all. Thanks for the giggle.

Yes, that’s how Ardupilot is designed.

What’s funny? No problem at all manually driving a Rover, or flying a Plane for that matter, w/o a flight controller. A multirotor you need a controller.

Its funny because obviously the answer is yes lol.

So it sounds like an external IMU would be my only option then. Is there a list on the doc with compatible imus?

Why not just use a Flight Controller? I must be missing something here.

complexity of wiring. If I could use a cheap external IMU that will really simplify things. No imu would be ideal but since it sounds like thats not possible and the compass would need to be external anyways mounting an imu in the same area as the compass wouldn’t be too terribly bad.

Well, Ardurover doesn’t run on an IMU it runs on a Microcontroller so you need that. Then you need an IMU. So AKA, a flight controller.

Oh sorry I guess I wasn’t clear. External IMU. IE an IMU to set as 1 mounted externally and disable all the internal IMU’s on the fc.

How is that less complexity of wiring? I’m not seeing the point here.

It would be really helpful if you could just trust me here and stick to the questions being asked. I could take the time to explain everything so you are on my page, but you could save me a lot of time by just listening to what i’m writing.

So do you think this IMU will work as an external? Does Ardu require a certain number of axis or is 3 enough?

https://www.amazon.com/HiLetgo-MPU-6050-Accelerometer-Gyroscope-Converter/dp/B00LP25V1A/ref=sr_1_11?crid=1RNOW29C3Q8MW&keywords=ardupilot%2Bexternal%2Bimu&qid=1694800614&sprefix=ardupilot%2Bextenal%2Bimu%2Caps%2C187&sr=8-11&th=1

what are you running ardupilot on?

The problem is that you need to be more specific. How are you going to run the firmware? You’re not making sense by remaining vague.

Not sure what FC i’ll use but Matek something.

A FC, as I said originally.

Then you already have IMUs at your disposal and we are all increasingly confused.

Your confusion would be lessened if you carefully read what i’ve written.

simplicity it got me wondering if its possible to rely only on gps/compass values and disable all onboard FC gyro/imu?

So as i’ve said previously if you can just trust me and stick to the questions being asked that would be tremendously more helpful.

To reiterate, does ardupilot support these cheap IMU’s as external? Is there a list somewhere with compatible IMU options?

Use the search function here for “external IMU”.

Lol gee thanks Dave lol

Your condescension is duly noted.

Here’s a related thread:
How to use external imus? - ArduPlane - ArduPilot Discourse

Good luck.