From Week 9 & onwards, the most difficult challenge we had to overcome was trying to balance M&T with other academic workload. However despite that we did manage to add in new features such as a rotating brush and a rain sensor.
During the addition of these feature the three major challenges was:
1. Attachment of the rotating brush
2. Calibration of the rain sensor
3. Simulating a water-proof casing
These challenges were mainly overcame through the usage of 3D printing and prototyping with heavy amounts of trial and error.