First Drive Common Questions

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

“My robot drives backward. Is it broken?”

No — a motor’s Direction just doesn’t match how it’s mounted. Flip that motor’s Direction (CLOCKWISE ↔ COUNTERCLOCKWISE) and run again. This is normal setup, not a fault.

If they want more: The two motors face opposite directions on the robot, so one of them almost always needs to be reversed for “forward” to mean forward.

“I ran straight(1000) but it didn’t go exactly a meter. Did I do something wrong?”

Nope — that’s exactly the point of calibration. The robot guesses its distance from wheel_diameter. If it drove too far, lower that number; too short, raise it. Try again until it lands on a meter.

“Which way is positive for turn()?”

Positive is clockwise / right. A negative number turns left. So turn(90) is a right quarter-turn and turn(-90) is a left one.

“What’s the difference between wheel_diameter and axle_track?”

wheel_diameter is how wide one wheel is — it controls how far the robot drives. axle_track is the gap between the two wheels — it controls how much it turns. Tune distance first, then turning.

“My hub isn’t in the Bluetooth list.”

Make sure it’s turned on and not already connected to another laptop (a hub can only talk to one at a time). Refresh the page and look for your hub’s name (it’s labeled).

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

Blocks are totally fine — you’ll learn the same things. Use the Block Coding Guide. You can peek at the live Python preview whenever you’re curious.

“Why does the square come back to a different spot?”

Small errors in each side and each turn add up over four moves — that’s real robotics. Tighten your calibration and it gets closer. “Pretty close” is a Day 1 win.

Teaching Notes for Instructors

The most common time sink today is first-time Bluetooth connecting. Have hubs named and labeled in advance, and connect one yourself first so you can walk students through the exact buttons. Resist giving students “correct” calibration numbers — the measuring-and-adjusting loop is the entire lesson. Celebrate the first successful drive loudly; it’s the moment that hooks them for the week.