Between 18^th and 21^st of August seventh Summer School of Mechanical Engineering took place at Faculty of Mechanical Engineering, University of Ljubljana. For the third time, one of the available workshops was Find a balloon and poke it – with a laser, organized by Laboratory for Laser Techniques. 

This time, four students participated at the workshop. Their final goal was to make a scanning head. It is a device, that enables us to direct a laser beam without moving a laser source itself. That’s why scanning head is used in many industrial applications. 

Firstly, an industrial laser system for laser marking was presented to the participants and they used it to write their names to a plate of their system. Then they soldered a simple electrical circuit to connect a low power laser pointer and two servo motors with an Arduino microcontroller. Two small mirrors were fixed to the servo motors to drive the laser beam; by moving the first motor the laser beam was moving in a horizontal direction and by moving the second one the beam moved in vertical direction. Further the participants connected a web camera to a personal computer and wrote a program for target recognition using Python programing language and OpenCV library. Once the system was complete, computer communicated with an Arduino via serial communication and was sending it commands to turn off and on the laser, move the motors and target tracking. 

Since out of a safety concern a low power laser pointer was used the system was unable to poke a balloon. To justify the name of the workshop we used a more powerful laser and poked some balloons.