Gyro Precision Common Questions

Keep answers short and friendly. Add detail only if students ask for more.

“What does the gyro actually do?”

It senses how the robot is turning, so the robot can feel which way it’s facing instead of just counting wheel-spins. With it on, the same turn() and straight() hold a straighter, more accurate path.

If they want more: Counting wheel-spins is fooled by slipping wheels and uneven floors; the gyro measures the actual rotation and corrects as it goes.

“I turned the gyro on but my 360° still isn’t perfect. Did I break it?”

No — that’s exactly the point of today. The gyro is better, not magic. A true full turn might need turn(357) or turn(362) on your hub. Tune the number until the heading lands back near 0. That’s calibration.

“Why does each hub need a different turn number?”

Tiny differences in the build, the wheels, and the gyro itself add up. There’s no universal number — yours is yours. Measuring it is the activity, not a failure.

“What’s a heading, and where do I see it?”

The heading is the direction the robot is facing, in degrees. It starts at 0 and positive is clockwise. Print it with print(hub.imu.heading()) and the number shows up in the output console in the editor.

“My heading didn’t start at 0.”

It resets to 0 when the program starts running. Read it after the program is going, and remember every turn adds to (or subtracts from) it.

“Do I have to rewrite all the setup from Day 1?”

No — reuse it. Same hub, motors, and DriveBase with your calibrated wheel_diameter and axle_track. The only new line is robot.use_gyro(True).

“How do I prove the gyro helped?”

Run the same move with the gyro off, mark where it ends, then run the exact same code with the gyro on. Measure both errors and chart them on the worksheet. The chart is the proof.

“Do I have to use Python? I want to use blocks.”

Blocks are totally fine — you’ll learn the same things. The drive base setup has a “use gyro” option, and there’s a heading block too. Use the Block Coding Guide.

Teaching Notes for Instructors

The proof of the day is the off-vs-on comparison, so make sure every team measures both runs — don’t let anyone skip straight to the gyro-on version. Resist handing out a “correct” turn-fudge number; the per-hub tuning (expect roughly 355-363) is genuine calibration and the whole point. Frame the gyro’s imperfection honestly: it’s a big upgrade, not a magic fix. Reuse the Day 1 setup so the new idea (use_gyro(True) and reading the heading) stands out cleanly.