This has neither. The black PCB seen to the right of the robot is an IR reflectance sensor. It shines an IR led at the floor and picks up what reflects back. [Sean] added this hack because the ...

He’s based the build around an Arduino and started adding different chunks to the project to develop a full-featured unit. It can take your temperature (with an IR sensor…. not the hard way ...

Finally, your Arduino toolkit will be incomplete ... or another temperature sensor. Likewise, ultrasonic and IR modules are ...