The Raspberry Pi platform is wonderful for DIY electronics and coding projects. The Adeept PiCar-Pro is a neat kit that lets you build a robot car with your Pi. It is compatible with Pi 4 and 3 models B & B+. This robot car will be able to track objects, follow lines, and avoid obstacles automatically.
This robot has a 4DOF robotic arm and open source code. It is ready for Python programming. You can remotely control it with your smartphone.