Instructors - Lesson 2

By the end of this lesson, students should be able to steer their robots using the flashlight on their phones. The resistor values used for the pull down are set in stone. The larger the resistor value, the more sensitive the LDR circuit because is now requires a smaller current for a larger voltage drop about the resistor. The lab where we run the course was quite bright so there was a lot of ambient light so we chose smaller resistors. We also cut about 15mm of black straw to fit around the LDRs to block ambient light.

Pre session

Prepare motor ICs, switches and resistors per person per table. Cut straws may also be needed.

During Session

The course leader should explain to each table what a motor driver is and its function in the robot (supply sufficient power to the motors). Explain how a potential divider works and how swapping one of the resistors with an LDR can be used to make the robot steer towards light.

Post session

Tidy up and debrief.