Do a real project with goals and expectations. Learn exactly what you need to get the task done. Do not buy a ROS book. Do not spend huge amounts of time exploring the ecosystem. Just focus on making it “do the thing”. The experience will come when the goals are met. Source: I built the entire initial software stack for the FarmBot project (minus the gcode handling firmware, thanks Tim) and had zero hardware experience when I started. I can compile embedded Linux kernels from scratch and whatnot now.

Get an arduino kit and learn a little electronics. The kit likely comes with a brushed motor and a servo. Learn how motors works and how to write code to make motors spin. Then get a stepper motor and an arduino-compatible motor shield or CNC shield and spend some time getting multiple motors to move. Once you understand those basics, you can hook motors together in a rigid frame and you have a robot (2 motors with wheels is mobile, 3 or 4 motors with links is an arm). The kit will also come with some simple sensors which you can use to do things like measure light and distance, which you can use to start playing with feedback control (look up Braitenberg vehicles for a project idea).

Seconding all the people who said avoid ROS - it's not worth the effort for hobby-level stuff. It's barely worth the effort for "professional" robotics.

Also don't worry about physics too much - build your physical intuition by playing with working systems of increasing complexity.

- Learn basic electronics.

- Learn about micro controllers and embedded programming.

- Learn about motors.

- Learn about gears, pulleys, torque - some physics things - enough to think about how you could potentially build something.

- Build something small. Maybe a robot sunflower that follows the sun with a built in solar panel that keeps its battery charged... I dunno, I just came up with that. Or an automatic blinds opener / closer for your blinds / home curtains.

- Learn, build, rinse, repeat..

I was very interested in athletic robots, so I left my job in software to build a quadruped and make it backflip [1]. I made the hardware at home (the design was open-source [2]) and wrote the framework to generate jumps, flips, etc. I started with basically zero robotics knowledge, so it was a lot of work, but it was incredibly fulfilling and super fun. I personally learn best by building things.

I'd say start playing with 3D printing and motors to make mechanisms that move (pendulums, simple walkers, ...). +1 to tinkering with the 3D printer itself (that someone mentioned) as you can learn a lot about how the machine works and figure out ways to improve it.

You've mentioned the physical aspect, but simulation could also be a good starting point. You can now very easily train RL agents in sim to say, walk, and transfer to real hardware afterwards.

Finally, if you like flying stuff, there's drones you can buy that are controlled programmatically (e.g. Crazyflie). I haven't played a lot with these, but I've seen them used to teach control and they seem like a nice, inexpensive platform to experiment with.

[1]: https://github.com/rkourdis/trajopt?tab=readme-ov-file#backf...

[2]: https://open-dynamic-robot-initiative.github.io

It really depends on what you want to do. Start with a list of projects you want to build. Are they really robotics or just home automation? If you have no experience with embedded programming, I'd start with home automation or other simple hardware stuff first. Learn how to read sensors and operate lights or motors before you get any deeper into the craft.

There are three reasons why "real" robotics is harder. First, to navigate unconstrained environments by means other than wheels, you need to learn a fair amount of kinematics and control theory. Second, your robot will need to build a map of the operating environment, which often requires complex sensing (lidars, cameras) and a lot of compute power. Even something as basic as a Roomba is no small feat, and these things get stuck a lot. Third, it's just hard to come up with practical applications for simple robots outside of industrial production lines.

Once you have that figured out, decide how much you want to learn. Do you want to do it the hard way, which would mean moving more slowly and working your way up from first principles and probably 3D printing or machining your own parts... or do you want to get results as soon as possible, in which case, you probably buy a Linux single-board computer and put it on top of an existing robot kit? The trade-off with the first approach is that it will take you months or years to get where you want to be. The downside of the second is that you're limited to premade kits and software components, and once you exhaust the possibilities there, you kinda hit a wall.

As someone who has been learning robotics as a hobby for a decade, my advice is: forget all the buzzwords and what the industry is using and start small instead.

I started robotics at a young age and began with small builds with LEGO motors and sensors, getting a feel of how each one works and how to interact with them with code. Then I got to much more advanced programs with LEGO Mindstorms EV3, learned about things like PID controllers practically and even started taking part in some competitions. Next, I went to writing actual code (as opposed to block-based programming) on microcontrollers like the micro:bit (and a few years later the Raspberry Pi Pico). I deepened my knowledge of how electronics work and learned how circuits work. I eventually got into a team with a few friends and we built a human-size robot combining 3D printing, a bunch of circuitry, ROS, 2 SBCs, Arduinos, a LIDAR and OpenCV for face/object recognition. This took years of learning step-by-step to achieve.

This is obviously not the path you'd take, robotics was what brought me into programming and you're probably going for the opposite.

You're not going to build a perfect robot or electronic device from the start and you shouldn't try to either. Get a microcontroller that's newcomer-friendly and play around with it. A micro:bit mostly emphasizes on the end result, with a built-in display and sensors and many plug-and-play modules to get you going. A Raspberry Pi Pico is much more flexible, but also requires you to learn about wiring and doing more things yourself. If you prefer coding in C, go for an Arduino. An ESP32 is also a good choice. It's a good idea to get a 3D printer and learn CAD in parallel, as it's a great way for a hobbyist to create actual tools that are more than a bunch of wires.

Once you get enough experience and confidence in your skills, you'll want to get into more advanced projects. Use your knowledge to plan them out, research and learn the technologies you're going to use (you can't learn everything beforehand and each piece of hardware is something different) and enjoy the journey from prototype to finished project.

And by the way (you didn't mention it but other comments here are so I'll give you an opinion on that), ROS is nearly always overkill for hobbyist robotics projects :D

I hope that helps you start your journey!

The simplest project that covers the basics of motors and controls is a self-balancing robot. 2 Motors, an h-bridge, a battery, an IMU, and a microcontroller.

A step above that I would say some kind of wheeled robot with more complex motors that have encoders, and ROS if you want to mess around with autonomy. If you have the budget for it, a stereo camera or $400 time-of-flight RGBD camera can get you pretty much full autonomy (if you configure all the ros nodes for it).

If you are into robot arms, LeRobot has a desktop robot arm kit that uses neural networks to control a robot arm with a camera for seeing the world.

If you want to learn the theory, I really like Probabilistic Robotics by Sebastian Thrun, and Modern Robotics by Lynch and Park. Those cover pretty much all of the foundational concepts for autonomous robots.

The most fun thing I think currently are drones. I have been designing and building a fixed-wing drone with autonomy and FPV capabilities. Started from zero information and just learned as I went. Plus flying drones is more fun than driving robots IMO.

I would always prefer to start with a kit that will work right a way end to end, than focus on each problem subset to do deep dive. so101 is a highly available 3d printed and servo motor based robotic arm. That can be combined with nvidia orin like sbc as a good starting point.

Worth to check also https://www.printables.com/ for small cute 3d printed robot projects that you can build using stm32 or esp32 boards. You shall check Adafruit/Sparkfun like websites for dev boards, they even support micro python for quick prototypes.

https://www.hackster.io/shahizat/running-lerobot-so-101-arm-...

I highly recommend starting with the very affordable and well documented Lerobot SO101 arms. You can 3d print or buy parts and actuators, camera. Lots of tutorials and training policies, data collection and simulations. https://huggingface.co/docs/lerobot/en/so101

My college robotics course used Lego Mindstorms (back before the kit was discontinued) because it offered quite a lot for the price.

Our robots needed only to complete a simple task of finding the "reactor" (array of IR LEDs) on a 1x1m fenced board, but Lego more than delivered on the hardware front, because we had an IR sensor, an ultrasound proximity sensor and few other ones that we didn't even use.

Really helped to bridge the gap between theory and practice because it's one thing to program a servo motor and a completely different one to see your dead reckoning algorithm be off by a mile. Also sensors do a lof of things you don't expect.

Its succesor is named Lego Spike Prime, but I never used it, so can't comment.