After speaking with Jiaqi (TA), we got a better understanding of how the Raspberry Pi would communicate with the User’s device. He told us to look into websocket (https://websockets.readthedocs.io/en/stable/intro.html). It can establish an asynchronous connection between the system that the webapp is on and the Raspberry Pi. It is easy to use with templates provided. He suggests that we can work towards an user interface with an lcd display (https://www.adafruit.com/product/2718) for MVP, which is easier to implement and does not need internet connection. After talking with him, we noticed that some nice features to add: the cart could automatically return to the starting point after finishing a path; also, according to robotic business class, the cart does not always need to follow the optimal path, but travel to items related to those on the list, so that it is more likely for customers to spend money.