The first field test went quite well for a first try. The challenge consisted of finding the presentation screen during a conference. The rover started out under a chair in the room and the kids had to maneuver it into position to see the screen.

One dark side moment occurred when the access point inadvertently turned off and had to be reactivated. 

The navigation process required some patience from the participants as the images currently take around 30 seconds to  upload. Also, the rover on two occasions started behaving weirdly, turning around continuously, as if it had gotten interrupted while the motor pins were high.

The http GET that sends the distance measurement fails, a problem that can be "fixed" by disabling the camera-related code. That dependency is quite weird and might be pointing at a stack or heap overflow.

It might anyways be a good idea to get rid of the SoftwareSerial library and use the hardware serial bus between the ESP and the Arduino. That will make debugging via the serial interface impossible and it might anyways be a good idea to be able to do debugging via the http requests.

In summary, the kids found the challenge highly motivating and that was by far the most important.