Learning programming has positive effect on children's development, and Tangible User Interfaces (TUIs) is a convenient way for teaching young children programming. TanProRobot 2.0 is a tangible system as well as a small-scale distributed embedded system designed for children at grades 1-2 to learn programming concepts. The system consists of three parts: tangible programming blocks, a robot car and several manipulatives. The input and output of the system are both tangible. Children can program the robot car to act certain actions by arranging the programming blocks. Also, children can interact with the car with manipulatives. TanProRobot 2.0 aims to introduce event handling concept and sensors to children. Through a user study with 11 children, we found that TanProRobot 2.0 is an interesting programming system for children, and it is easy to learn and to use. Furthermore, it could help children get a preliminary understanding of event handling concepts.