Need low latency, multitudinous things-to-drive

Sorry for the bizarre topic, I'm not quite sure how to address this--I'm lookiing for a device to drive but I'm not sure what I need.

I have a general idea for an "artistic" sort of project that, ideally, would include lots and lots of moving bits. For example, it would be nice if I could find a bunch of cheap, small actuators (I can't seem to find these to exist) that I could assemble in arrays and "do stuff with".

I'm not even overly particular about what it does--spin, thrust, jiggle--whatever. I'll figure out what to do with them based on what they are capable of. I'd pondered piezoelectric elements of some sort, ie. you apply current and they bend--but I can't seem to find these, either.

Is this making any sense at all? Think maybe instead of a grid of LED's you've got a grid of moving things. Any ideas? They would be greatly appreciated!

Best,
Lee

You need a system to allow many things to happen together?
These will teach you an approach and basic techniques to do that.

Nick Gammon on multitasking Arduinos:

  1. Gammon Forum : Electronics : Microprocessors : How to do multiple things at once ... like cook bacon and eggs
  2. Gammon Forum : Electronics : Microprocessors : How to process incoming serial data without blocking
  3. Gammon Forum : Electronics : Microprocessors : Interrupts

What do you mean by cheap? Small servos are available for about £3 each (maybe even less) and they are easy to control. If you are content with less-elaborate motion then solenoids or electromagnets might be an option. If you want something that rotates without fine control over the amount of rotation simple DC motors are available for £1.50 or less

Servos have the great advantage that the motor driver is contained in the package. If you use solenoids or DC motors etc you will need something between the Arduino and the device - because the Arduino cannot directly control the power required.

You can get very small stepper motors (such as are use in car dashboard instruments) very cheaply - but they are a bit more complex to control and that could become an obstacle if you need a large number of them

...R

Solenoids?

How does latency enter into it? You need the movements to react quickly to some kind of user input? It doesn't even sound like you need much coordination between the moving units. If they aren't likely to collide with each other then they don't have to be synchronised.

Thanks y'all for the input!

Yeah I'm just trying to figure out what type of devices I could drive. The b*tch about so many of them is that it is hard to drive a large number of them. I gotta be honest, I'm kinda surprised there isn't a shield or other board out there for controlling a larger number of DC motors or steppers.

But then again, i'm a novice to this stuff and I have a feeling there's an excellent reason for that lol.

A motor is a tool that converts electrical energy into some sort of motion.

Just like there are millions of different sizes and types of tools, each with its own specific use, there are millions of different types of DC motors and steppers, all with different characteristics (torque, speed, etc.), requiring different voltages, currents and control signals.

Therefore, it is unreasonable to expect that someone would make and hope to sell a shield that might somehow control "large numbers of motors or steppers". That said, you can buy boards that will control 18 to 24 servos, because they are standardized.

Artists who are successful at creating complicated, electrified moving exhibits generally have to be part time mechanical and electrical engineers, or collaborate with someone who is.

rastoboy:
Thanks y'all for the input!

Yeah I'm just trying to figure out what type of devices I could drive. The b*tch about so many of them is that it is hard to drive a large number of them. I gotta be honest, I'm kinda surprised there isn't a shield or other board out there for controlling a larger number of DC motors or steppers.

But then again, i'm a novice to this stuff and I have a feeling there's an excellent reason for that lol.

Try Crossroads site. Bob's a member here, he's an EE and does sell multi-relay boards.
http://www.crossroadsfencing.com/BobuinoRev17/

Do a search for arduino multiple motor driver and you get loads of hits. Adafruit has a motor shield kit for Uno rev 2 that they show with 5 small motors connected.

In every case you need to be sure that the board in question -can- drive the motors you want, and how many. The boards with the heat sinks tend to be for non-toy motors, prices rise with the amount of current usable.

If you have a slim budget then crack down and learn to DIY or reel in your expectations some. If you DIY then build small to learn before you end up with a bunch of parts and huge plan with some major flaw. It's easy to buy stuff, including wrong stuff.

PS, don't forget to throw in lots of leds, lights catch the eye. RGB, UV (makes white and day-glow 'pop'), 2-color led that make a 3rd with both on (red-green led also makes amber) are usually cheaper than RGB, and our old low-cost friends the single-color leds. And then there's led strips and addressable led strips and bar graphs and 8x8 led squares that can be tiled.

I don't know obout other motors but vibration motors are very small and very cheap (at least on eBay). They also don't need much power.

@jremington. I see. Or I get the idea, anyway. I've got a lot more learning to do.

@GoForSmoke interesting!

@Smajdalf: vibration motors, eh? indeed, I see they don't draw a ton of current, and might possibly be quite interesting to play with. I kinda feel like I probably am not yet competent to be playing with lots of juice yet, too, so that's a nice appeal lol.

...and remember, you'll need adequate power (voltage x current) to drive those multitudes!

+1 on the adequate power and add to that, use heavy ground wire (of case chassis) if possible and connect all non-isolated grounds!

Rastoboy, if you're up to cookbook DIY then you can program bare 328P chips (the one in socketed Unos) to make stand-alone controllers with a few parts. What goes on a breadboard can be soldered to a protoboard or a socket or right to the chip if you're real good at soldering. Don't believe?
http://make.kosakalab.com/arduino/obaka/project-2/index_en.html

The full howto on programming bare 328P on a breadboard circuit, with many different configurations/setups.
http://gammon.com.au/breadboard

Futurlec sold 328P chips for $2.20 ea (or 100 for $2 ea) which is cheaper than most motor drivers. One 328P can run a few drivers as a module you can build into a panel. If you need more pins then look to shift registers and led driver chips, people on Youtube show controlling 256 RGB leds (768 led pins) with a single 328P-chip Arduino and banks of those "pin multipier" chips. You can cover a meter square easily but remember, some devices need more CPU attention than others. You can think in terms of how much attention your controller has vs how much each device needs. Tile panels to make a big display and the complexity will be reduced over 1 big controller (Mega2560) trying to do it all with the same core as the 328P.

Super informative and interesting. Thank you!

Robin2...

You can get very small stepper motors (such as are use in car dashboard instruments) very cheaply - but they are a bit more complex to control and that could become an obstacle if you need a large number of them

I've been looking for these - where do you get them?

Allan

You can also salvage quartz controlled alarm clocks with hands. They have a super simple single pole stepper motor that turns the clock hands in them.

Check out the book Electronics for Artists[/url] for the 'how-to'.

I'm looking for a copy of Electronics For Dogs. Saw it in a movie short a few years ago.

You're a dog?

So I went out and got a passle of vibrator motors as Smajdalf suggested, and these might be a great contender! Question though. I just hooked one up to the arduino with a transistor and diode, and it seems to work fine. It seems like with a power supply and enough PWM pins, I could drive as many as I'd like this way.

What is the advantage of using a driver board?

rastoboy:
So I went out and got a passle of vibrator motors as Smajdalf suggested, and these might be a great contender! Question though. I just hooked one up to the arduino with a transistor and diode, and it seems to work fine. It seems like with a power supply and enough PWM pins, I could drive as many as I'd like this way.

What is the advantage of using a driver board?

You don't need a passle of transistors and diodes. :slight_smile:

yeah but...again, i'm a novice, i'm sure i'm spouting nonsense...but the driver boards i've seen can only do 4 motors at most. and my notion is to have maybe a few dozen. wouldn't it be even more unwieldy?