#robotics Logs

Mar 13 2021

07:27 AM Phrkd is now known as Phreaked
01:34 PM gartt: What's good hardware for basic prototyping of robotics (just to experiment with software using stuff like Arduinos and RPis, nothing commercial quality)? Lego Technic pieces seem to be the best candidate from googling. Aluminum parts (Like Vex IQ) aren't necessary and plastic is fine
01:37 PM veverak: totemamker
01:37 PM veverak: https://totemmaker.net/ this for mechanics
01:37 PM veverak: than it depends on what you want to do
01:37 PM veverak: "rc cars" or other radio controller equipment is usefull
01:39 PM veverak: there is strong argument to consider what is available in your location
01:40 PM gartt: veverak: Ah, I came across Totemmaker as well. Good option, but not as able to tear down and rebuild easily, even though it's much sturdier
01:41 PM veverak: hu?
01:41 PM veverak: it's as easy as it gets
01:41 PM veverak: and you can't really make it anyeasier without sacrificing some vital property
01:42 PM gartt: veverak: In comparison to snapping stuff together with Technic parts?
01:42 PM veverak: yeah
01:43 PM veverak: lego sacrifices vital properties
01:43 PM gartt: I agree, but for basic prototyping, you'd go with totemmaker?
01:43 PM veverak: yes
01:43 PM veverak: I have three XL kits hidden under the table
01:46 PM gartt: Cool, I'll research about these
01:47 PM veverak: in some context LEGO is good enough
01:47 PM veverak: but it is definetly not a thing to recommend "in generall"
01:47 PM veverak: (as you did not specify what exactly you want to do)
01:49 PM gartt: I wasn't super clear. I was shooting for basic wheeled operation and playing with robotic arm, camera panning, etc. Simple things
01:49 PM gartt: No real physical stress
01:49 PM veverak: robotic arm from LEGO is much trickier than from totem
01:50 PM gartt: Due to the bulkiness and lack of angles/flexibility you mean?
01:50 PM veverak: and due to the fact that it is pressed together and not screwed
01:50 PM veverak: it's much harder to make robotic arm that is sturdy enough to move decently
01:51 PM gartt: That's true
01:51 PM veverak: that's true in general
01:51 PM veverak: it's easy to have sturdy totem construction for robots
01:51 PM veverak: relative to having same thing from lego
01:51 PM veverak: and you do care about "sturdy' in case we compare totem and lego
01:52 PM gartt: veverak: Any other options for basics like I mentioned? Or would it be totem with Lego Technic as a runner up?
01:52 PM veverak: 3d printer :)
01:52 PM veverak: and depends on what you are asking
01:52 PM veverak: I use totem only for mechanic part, not their electronics
01:53 PM gartt: veverak: What do you use in terms of brains? RPi, arduino?
01:54 PM veverak: rpi + something embedded
01:54 PM veverak: for simple prototypes arduino, for komplex prototypes stm32 devel boards (that is outside of beginners range of skill) and for products custom boards with stm32
01:55 PM veverak: and recently I found rpi pico interesting
01:55 PM gartt: Well, no additional research needed there at least. You use servos and linear actuators, or have you played with pneumatics or hobbying hydraulics?
01:55 PM veverak: rc servos, or smart servomotors with full feedback
01:55 PM veverak: also using rc motors + rc esc in a lot of cases
01:55 PM veverak: recently switched with everything on 18650 batteries
01:56 PM gartt: veverak: What are your thoughts on using a powerbank (such as used to recharge phones/tablets) and using USB cable to charge an RPi?
01:57 PM gartt: to power* a raspberry pi
01:57 PM veverak: it makes sense for a lot of use cases
01:58 PM veverak: BUT
01:58 PM veverak: it's tricky to power motors from it
01:58 PM gartt: How so?
01:58 PM gartt: Why would it supply less than 18650?
01:59 PM veverak: and at lower voltage
01:59 PM veverak: less current at lower voltage
02:00 PM veverak: thing about 18650 is that it's not much more hustle to use them in the project (they are simple to use and charge)
02:00 PM veverak: powerbanks are usually heavier than adequate 18650 setup
02:00 PM gartt: I see. It'd be nice to have something that could be recharged without having to power off, which is what made me think of powerbanks
02:00 PM veverak: (which in case of small robots can have drastic effects)
02:00 PM veverak: you sure you have powerbank that can do that? :)
02:01 PM veverak: anyway, yes, it seems nice
02:01 PM veverak: but I do not find it worth the hussle
02:01 PM veverak: (as, it's not something that I would actually need)
02:01 PM gartt: I understand. What would you suggest in terms of something that could be charged while providing power?
02:02 PM veverak: I am not aware of anything that can does that, without being hella expensive
02:03 PM veverak: (because I do not need it, so do not have the urge to study this)
02:03 PM veverak: last time I studies this, there was nothing as "ready to use solution" and it would require to build the elctronics to do se by myself
02:04 PM veverak: *to do so by myself
02:04 PM veverak: there are special ICs to handle it
02:05 PM gartt: Expense isn't a huge deal if I could use for other purposes. I was thinking of those camping power banks with solar panels used to power smallish devices - and being able to be charged while supplying power
02:05 PM veverak: but I will repeat myself
02:05 PM veverak: it is not as necessary as it seems
02:06 PM veverak: so I would not waste time on it
02:06 PM veverak: if you are beginner, there is other stuff to worry about :P
02:06 PM gartt: veverak: Thanks, I'll table that part
02:07 PM veverak: last project where it made sense was solar powered boat
02:07 PM veverak: now that I think of it, yeah "electronics to handle solar+lipo" is the answer
02:08 PM gartt: veverak: Would be cool for a poor man's tree-mounted home security camera, coupled with a raspberry pi zero
02:08 PM veverak: that can be tricky to get right
02:08 PM veverak: :)
02:09 PM gartt: Since the battery bank would have plenty of capacity to supply power on overcast days and nights due to its size
02:09 PM gartt: veverak: You mean in terms of draw by the pi, or issues about using a solar-powered camp powerbank in an enclosure in different temps?
02:11 PM veverak: everything togethere
02:11 PM veverak: *together
02:11 PM gartt: veverak: How so? If the pi zero is using motion detection software to detect movement and not transmitting constantly, it'd be using pretty low power, right?
02:12 PM veverak: that software takes some power
02:14 PM gartt: But with something like https://www.rei.com/product/155547/goal-zero-sherpa-100pd-power-bank supplying power and the low usage of a pi 0, you'd not recommend?
02:22 PM veverak: not sure it would work out
02:23 PM veverak: thing is, you should not guess these things
02:23 PM veverak: calculate power usage of rpi + camera + other stuff, calculate required capacity of battery, calculate require power of solar ... at really bad day
02:25 PM veverak: and I would read several blog posts from people _with longterm experience_
02:28 PM gartt: veverak: Understood, you're right
02:29 PM gartt: I was guessing by posts lke these https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=127210
02:31 PM veverak: if you want camera, you won't have idle consumption
02:32 PM gartt: And with periodic sending of video over wifi, even more juice used, but at least it gives some idea. But like you said, power options like that would probably be the last thing I should be researching
02:36 PM veverak: select a simple robotics project
02:36 PM veverak: it's good to make small steps :)
02:56 PM gartt: Walk before I can run? Absurd advice
05:14 PM Atomsk is now known as ace4016
06:13 PM sorki is now known as srk