Warm Up

Have the presentation open before the lesson starts. Ask learners if they know what parkour is and what people need to do to perform parkour. Have learners list their ideas in the workbook; this could be done individually, as part of a group, or as a whole class. Encourage learners to describe how to perform any of the moves that they know.

Encourage learners to show mini models of the moves in parkour, perhaps using their fingers as legs and jumping off surfaces like books on their desk or other small obstacles they could use. There is a video on slide 2 of the presentation that is a fun display of some finger parkour. This can be deleted if you do not need it.

After a chance to describe moves, show the clip from slide 3 in the presentation - Atlas performing parkour. Have learners think about what a robot would need to be able to do what a person can do.

Following a discussion around the videos, share the objectives and success criteria on slides 4 and 5.

Get Learning

Robots need sensors to respond to their environment and they need instructions for what to do after they sense different objects. Marty has an obstacle sensor that comes attached to their foot and the color sensor also detects obstacles. What do we need to think about, for Marty, in order to respond to an obstacle?

Show a response from Marty upon approaching an obstacle. There is a video on slide 6 of the presentation that shows Marty's reactions to an obstacle.

Question ideas are in the presentation notes on slide 6.

Share with learners an image of the IR sensor and a slide of how it works (slides 7 and 8 in the presentation). Explain that the IR sensor gets feedback from light that reflects off the wall and that is how Marty 'knows' something is in the way.

Below are images of Marty's sensor and a diagram of how the sensor works

The responses from the sensor are described on slide 8.

Learners may have already learned about something called BOOLEANs, these are pieces of code that take only two values; for Marty, they are true or false. When you go to the sensing tab on MartyBlocks and press the 'Foot obstacle sensed' block, if there is nothing directly in front of the foot with the sensor, this will return false. If there is something there, it will return true. It would help to show this on a device screen to the class, so that they can appreciate how close Marty needs to be to react by moving Marty close to an object and pressing the foot sensing block on the device and then repeating this when moving Marty farther away. Alternatively, tapping the box beside the block will keep the feedback from the distance sensor on the workspace.

Click here for more information on the obstacle sensor.

Slide 9, from the presentation, shows the most basic code to have Marty respond to an obstacle. Slide 10 shows the code in action.

There are ideas for discussion, on slide 9, for the code as well as locations for each of the blocks.

Time For Practice

There are questions on slide 11 to promote learners to think about how they could improve on Marty's code. They may have noticed that the Marty from the second video was only two steps from the wall, so taking two steps would result in the sensor returning true. Try running code on the class Marty from a greater distance. What can we do to ensure Marty reaches and detects an obstacle so that they can react to it?

Learners may suggest using a repeat block, but you could also say that they should keep their ideas within their group to encourage a greater diversity of responses.

Have a whole-class planning session with ideas for how you can improve on the basic code, which will enable Marty to respond to objects that are initially farther away. You will need to decide if you are entering the code into the app for Marty to perform, if there is a learner in your class who will have this responsibility or if you want groups to enter the code on their iPads and then connect to Marty when they are ready.

Cool Down

Take time to discuss the learning that occurred.

Suggested questions you might ask:

• What was interesting or challenging about using the obstacle sensor?
• What modifications would you suggest for someone designing a new obstacle sensor?
• Where are some other areas of our lives where an obstacle sensor is a helpful tool?

Carry out any end of lesson routines.

Log off devices and clear everything away.