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Comment by biinui | Hacker News Reader

May you kindly point me where to start learning robotics, and recommendation for a starter robot arm? Maybe ~$300 if something worthwhile exists at that price range. Take care.

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Not OP. This is not necessarily the friendliest or best place to start, but in terms of hardware costs it's great: the ST-Micro P-NUCLEO-IHM001:

https://www.st.com/en/evaluation-tools/p-nucleo-ihm001.html

For $35 you get a little motor, a motor control board, and an ARM micro-controller board. ST includes some software for motor control. If you want to do precision motor control, out of the box it is missing an encoder (a device that tells you the position of the motor). The STM32 chips usually have some inputs you can use with a quadrature encoder, so you could add one if you needed to. It does include a current sensor and the software uses the for field-oriented control (FOC), so you can efficiently and smoothly control the speed of the motor. To learn more about motor commutation and FOC, check out this document:

https://www.actronic-solutions.de/files/actronic/FTPROOT/Fie...

Strange, I was pretty sure your parent was asking sarcastically!

Lego Mindstorms could be worth considering as a general-purpose hobby robotics platform: EV3 (the older version) can be flashed with a custom Linux distro, and Robot Inventor (the newer one) can run Python scripts. In either case all you need to add more structural parts is to pick up a bulk case of used Technic parts, so it's eminently reusable for multiple unrelated projects.

For an example of stuff people have built with them, here's a Robot Inventor-based Rubik's cube solver: https://www.youtube.com/watch?v=_cl2Wur8waY

Oh jeeze, I feel old if the EV3 is being described as "the older one". I have horrible memories of writing some "Not Quite C" for RCX because the compiler didn't support modern amenities like stack frames.

Being able to just run Linux on the thing sounds like a god send.

A group I worked with in a high school lego robotics competition managed, if I recall correctly, to achieve 'recursion' by defining 2 very similar functions and having them just call each other. It was a frustrating device at times but also a really fun experience!

Is called a trampoline, a standard trick more or less.

Cool! That makes sense -- it still felt incredibly clever and tricksy to us when we were about 16 and trying to map our 'beautiful algorithm' into NQC sometime past midnight, for a morning competition.

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