A shopping trolley is a necessary tool for shopping in supermarkets or grocery stores. However, there are shopping trolleys abandoned everywhere in supermarkets after being used. In addition, there are also shopping trolley safety issues such as sliding down from an escalator. It is known to be an inconvenience and time wasting for customers who are in rush to search for desired products in a supermarket. Therefore, an automatic human and line following shopping trolley with a smart shopping system is developed to solve these problems. A line following portable robot is installed under the trolley to lead the users to the items' location that they plan to purchase in the supermarket. This paper presents the hardware and software design of the portable robot. The result of the testing on the used sensors like ultrasonic and line sensors are presented. Lastly, the graphical user interface of Android application during the shopping trolley in operation is explained.