Rover rolls down a straight lane toward a wall. Choose one motor power and a sensor threshold that leave the cart in the safe stopping band.
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Simulation only: this bounded model does not control hardware. Your choices and predictions clear when you leave. If you turn saving on, only which puzzles you finished and how much help you used is kept on this device. Test accounts also share it, and lesson timing, with the site’s maintainer.
Step through a separate lane with actual sensor readings.
◇ Your mastery goalM17 · Motor and distance sensor
Complete all 3 required tasks with a correct prediction, an inspected trace and an explanation that shows the concept. At least 2 must be independent checks, without answer-level help.
Use power 1 to approach a wall and stop 3–8 cm away. Pick a threshold that also works on changed distances.
Read the lane
Start0 cm from lane originWall30 cm from lane originStarting sensor30 cmTarget band3–8 cm before wall
Wall🤖0 cm
The distance sensor reads wall − position before every one-second movement tick.
Build the controller
Choose the motor power and distance where Rover should command zero power. Power 1 is requested for this task; powers 1, 2 and 3 travel 2, 4 and 6 cm per tick.
At each sensor check, the controller either stops when the reading is at most your threshold or moves forward one whole tick.
Predict before running
Predict the final position and wall distance, movement ticks, and sensor checks. A normal stop includes one last check with no movement after it.
Help for this laneHints build up. Worked help and solutions are deliberate choices.
Highest help used here: none
For Further Reading and Exploration
These are outside sites with their own rules. You will see a notice before you leave. Pick one, not all.
Open Roberta Lab
Use blocks to drive a virtual robot's motors in a simulator. See what changes with a different speed or time. Logging in is only for saving.
Hands-on
Has accounts
Tinkercad Circuits
Build a virtual circuit with a motor and run code to spin it. No parts to buy. Making an account needs a parent or guardian.
Hands-on
Has accounts
May count visits
Webots robot simulator
A free robot simulator that supports Python controllers. It needs a big install on a capable computer, so an adult should help.
Hands-on
May need an install
Ask an adult
May count visits
Raspberry Pi Foundation Projects
Step-by-step projects. Some use sensors or motors and need hardware, so read the parts list before you start.
Hands-on
May count visits
Some extra resources are hidden. A parent or guardian can show them in Help.