The GPS buoy gets a compass

Cheap parts can be bought online. I bought this compass for about a hundred NOK. It also has an accelerometer—maybe useful later.

To keep a drone buoy fixed at a specific geographic coordinate, I need to steer it to a specific bearing.

Since it will maneuver in tight spaces, two motors are likely better than one motor plus a rudder.

Here are two motors (with propellers) and an ESC. The compass is mounted to a clip. The system can be set to a given heading (e.g., NW 315). Then port/starboard thrust is applied to point the bow to 315 degrees.

Later I’ll add the GPS.

Pseudo-algorithm:

loop:
  1) Where is the buoy relative to the desired target point?
  2) Compute bearing and distance to the target point.
  3) Set motor speeds to move closer to the target.