TUR-03: Servo turret - two measured points and its start angle

medium priorityReal robotabout 30 minTurret

• Your robot needs: Turret.
• Starter bots that fit: none (it needs parts the starter bots do not have).
• Library version: v0.17.0 or newer.
• The docs it tests: Setting up a turret, Finding your numbers (the finders), Hardware module.

Why

A turret on a standard servo has no encoder and no PID: the library turns an angle into a servo position from two measured points. A servo cannot say where it is, so at START it is sent to its start angle. A small, cheap turret is common on new teams' robots; we have only tried it in the simulator.

Safety

• The servo moves at START. Fingers and wires away from it.
• Listen for a humming servo at the ends: that is a servo pushing on a stop. Back off at once.

Setup

• Turret.servo("turret") in Robot.java (add .follows(camera) to test the aim too).
• Tunables.Turret: posA, angleA, posB, angleB from the Servo Finder and a phone angle app, and travelSec (time a move from posA to posB).
• Optional: .fullRange() on the line for the servo's whole turn (MEC-02). Measure posA and posB after turning it on.

Steps

1. INIT. Nothing moves. Read the turret's INIT lines.
2. START. The turret goes to its startAngle (or the middle of its range if you wrote none).
3. Turn it with the stick (gamepad 2 right stick X) to 0, then to each end. Measure the real angle each time with the phone app.
4. Turn it to 4 angles between the ends (by stick, or with robot.turret.aimAt(degrees) on a button). Measure each.
5. With .follows(camera): let it follow the goal. It reads AIMED only after travelSec has passed since its last move.

Pass rule

At each of the 6 angles in steps 3 and 4 the real angle is within 3 degrees of the Driver Station's, and the servo never hums at an end (0 times).

Record

Write these down while you test. The report form has them as a list to fill in.

• servo model, gears, and whether you used .fullRange()
• posA, angleA, posB, angleB, travelSec
• each angle: Driver Station vs measured
• how long AIMED took after a move (about)

If your robot is different

A servo turret on a linkage (not straight gears) turns unevenly between the ends: say how far off the middle angles were. A continuous-rotation servo with an encoder is a different kind: Turret.crServo(...), see the turret setup guide.

Report your result

Pass, fail, or could not run: every result helps. The form opens on GitHub with this test filled in (a free GitHub account is needed). No student names, please.

Report result

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