HN Explorer

Ask HN: Whats the coolest thing you've seen/done with Arduino?

24 points by rodrigo ↗ HN
I think im not "getting" Arduino or Arduino-like platforms possibilities. Please share whatever you've seen or done with it.

26 comments

[ 2.9 ms ] story [ 68.2 ms ] thread
mwilliams_
My Barduino (shameless self promotion).

Ruby + Arduino = Drink dispensing Barmonkey driven by a Ruby DSL that cost me like $50 to build.

Example recipe:

drink 'Screwdriver' do

  serve_in 'Highball Glass'

  ingredients do

    2.ounces :vodka

    5.ounces :orange_juice

  end
end

Code, video, photos: http://www.matthewdavidwilliams.com/2008/10/17/introducing-b...

otto
What type of pumps did you use, the link for them didn't work?

I've been trying to find cheap food-grade pumps for a similar project.

mwilliams_
They were just cheapo (but new) windshield washer fluid pumps. Apply 12v and they go. One of the pumps died after I demo'd it at Rubyconf and served 30 or so drinks during a talk. $10 a piece. You can Google around to find similar pumps.
HeyLaughingBoy
One way around using food grade pumps is to seal the container and pressurize it with air so the pump never comes in contact with liquid. You can have some problems with pumps outgassing and contaminating the air, so I wouldn't rely on that method for a commercial product.

A much simpler way is to gravity feed the liquid. You can make pinch valves (like on school cafeteria milk dispensers) from a solenoid or a small R/C servo motor and only the tubing that comes in contact with fluid has to be food grade. That stuff is easy enough to find (and cheaper than food grade pumps).

bct
What I don't get is why you'd pay $35+ for an Arduino when you can get an AVR (the microcontroller at the heart of an Arduino) for $5+.
gamache
It's a lot easier to get going on a project with a prototyping board. There are also many "shields" (daughterboards) which are designed to fit atop the Arduino: things like motor controllers, GPS modules, wireless ethernet cards, etc. Once a prototype has been worked out, the designer can then design their own circuit using standalone AVRs.
iigs
I paid for a sizably more expensive ($60+) kit with one (or more properly, had one paid for for me for Christmas) because it's a ready to go kit with a USB-serial interface, some other support circuitry, and firmware in it already.

I suppose if I ever blow up the microcontroller I'll buy an unprogrammed one and reprogram + install it, but by far the compelling thing about it is that you get all of the parts in one box and can start tinkering on Christmas day. If you just get the MC you have to get a breadboard, USB support guts, and any other stuff separately before you can start using it.

paulgb
The $35+ Arduinos usually have a USB port. Some Arduino (non-USB) clones are now less than $20. It's still a fair bit more than $5, but when you don't know what you're doing, a kit is better than trying to acquire all the parts yourself.
st3fan
I don't. I get these http://moderndevice.com/RBBB_revB.shtml ... you basically get 5 ATMega328 + power supply for 48 USD. Not a bad deal I think. They fit nicely into a breadboard or you can use them in a more permanent setting.
Titanous
I connected a PS2 barcode reader to a Sanguino, and programmed it to store the scans in memory, then dump them when sent a specific serial command. This allows me to scan a pile of books for LibraryThing when I'm not at my computer.
gamache
I'm using mine to replace the ignition system on my motorcycle (1979 Honda CX500). The original system is a lovely piece of electrical engineering, but is prone to stator coil and capacitor failure (respectively, by heat and age). The Arduino will allow proper ignition timing to be maintained even as three of four timing coils fail.
weaksauce
That's pretty cool. Have you considered making the design open source?
gamache
It will absolutely be open source. I just need to complete it first. :)
joel_feather
That sounds like a bad idea to me. Arduino electronics are not designed to withstand vibrations, and they will go kapput very quickly.
gamache
The finished product will just use an AVR, not a whole Arduino.
paulgerhardt
The micrcontroller community today is analogous to the personal computer/homebrew computer clubs in the early 70's - except with more embedded applications.

I've written code for one Arduino to run a python script to order pizza when one pushes a button (this used to be on my fridge.)

I used Arduinos as the processing, communications, and power modules for an augmented reality/robotics project where virtual balls projected on a dry erase board bounced off robotic devices (like a see-saw) and the devices reacted appropriately.

Currently I'm writing a program for the Atmel to query how many days left until YC demo day - and light up a corresponding massive LED display mounted on our wall.

You should check out LadyAda's site - most of her modules totally rock - especially the xbee and motor shield stuff. http://adafruit.com/

rodrigo
That same analogy is what caugth my attention in the first place. I still cannot visualize wich is going to be the killer app.
abdels
>> The micrcontroller community today is analogous to the personal computer/homebrew computer clubs in the early 70's...

I totally agree, in fact I was harping on this to great lengths just a few days ago :-))

rodrigo
Great things here, thank you for your replies.