144
you are viewing a single comment's thread
view the rest of the comments
view the rest of the comments
this post was submitted on 12 Dec 2023
144 points (93.9% liked)
Asklemmy
44149 readers
1421 users here now
A loosely moderated place to ask open-ended questions
Search asklemmy ๐
If your post meets the following criteria, it's welcome here!
- Open-ended question
- Not offensive: at this point, we do not have the bandwidth to moderate overtly political discussions. Assume best intent and be excellent to each other.
- Not regarding using or support for Lemmy: context, see the list of support communities and tools for finding communities below
- Not ad nauseam inducing: please make sure it is a question that would be new to most members
- An actual topic of discussion
Looking for support?
Looking for a community?
- Lemmyverse: community search
- sub.rehab: maps old subreddits to fediverse options, marks official as such
- !lemmy411@lemmy.ca: a community for finding communities
~Icon~ ~by~ ~@Double_A@discuss.tchncs.de~
founded 5 years ago
MODERATORS
I'm sad now that I've never had a "build a robot together" friend
Well, you can have one now, if you want!
I usually build around the Pi pico as a brain, L9110 motor controllers, N20 DC brushed motors, and a standard 18650 lithium cell, and some generic BMS + switch mode voltage converters. From there you can either add sensors and make it autonomous (more challenging), or just control it via your smartphone (easier). You can either make it omnidirectional with mecanum wheels, (more expensive) or turn/forward/back motion only with a differential drive.
Along the way you'll learn to solder and code, if you don't know already. It's a suitable beginner to intermediate project. Most of the work is knowing what cheap parts work well together (read and interpret lots of datasheets), actually assembling and using the robot is pretty easy. Usually I can keep cost under 50$, but parts are cheap here -- certainly under 75$ in the West though.
Well damn... Now I have another project!
I have a Pi 3 sitting around that I used to use for Octoprint, but when I rearranged my workstation I didn't have room for the monitor so I just went back to SD carding it. I picked up an end of service Chromebook that I was going to dump Linux on and make it my new print server, so the Pi is free.
I'm going to end up with my own little astromech Droid!
That's a bit overkill in terms of processing power, but it will definitely work! It's actually powerful enough to do machine vision and mapping!
One thing to remember is that the current draw for the Pi 3 will be much higher than the Pi Pico. Some students have had battery issues using motors + the Pi at the same time. They got the batteries in a sketchy industrial market here in VN though, so they were definitely not rated for very high current. This is one reason I use the Pi Pico and low power 6V motors -- it runs all day of a single very questionable lithium cell. Boots in milliseconds too, vs. much longer on Raspberry Pi + Debian, at the risk of comparing apples and oranges.
Another thing that was annoying, is to remember to put nonpolar capacitors across your motors if building your own motor controllers (most modules you buy will do this for you). Otherwise, noise from the e.g. brushed motors will probably make the Pi reboot constantly. I had this problem pretty bad -- it worked fine hand-soldered but when I got the boards from the factory it would fail often unless I put the caps in.
Anyway, if you're short on time and want to get the project done, there's also a thing called the Motorshield that will let you very quickly build a robot from the Pi you have. There are also LiDAR shields if you want to try mapping and fancy autonomous navigation. If you want cheap, you can't beat this motor controller module though (and you'll just need 1 for a differential-drive rover):
https://hshop.vn/products/mach-dieu-khien-dong-co-dc-l9110
You can generally find it anywhere in the world!