Compatibility of Holybro pix32 Flight Controller

Hello everyone,

My team and I are planning to build an Underwater Rover and we are planning on using the Holybro pix32 Flight Controller instead of the originally planned Pixhawk 1 (which has been discontinued) But we are concerned about its compatibility.

In PX4 User Guide, it mentions that the pix32 is physically very similar to the 3DR Pixhawk or mRo Pixhawk, but not connector compatible. What does it mean by “not connector compatible”?

We are quite new to this and PixHawks in general. Any clarification helps.

Thank you