Roomac is a mobile manipulation platform that I was able to build for 550$. It consists of a differential drive mobile base and a 5-DoF manipulator with a gripper. Software is based on ROS, as a proof-of-concept application I implemented fetching bottle to the user. You can find out more about this project in my master's thesis and on the Github repository.
Github repo:
https://github.com/macorobots/roomac_ros
