USB scales

[Chairman Cheyco]

So these USB scales have been rolling around in the old croth for a few days now and it hit me: If you put a couple of them together and attached them to a hub, you could then use them in your keggerator to monitor your keg levels in real time! No more 'Hmm, I should have enough left in that keg...'

Any thoughts from the guys who have these?

 

[Brewpastor]

With the right program you could keep an eye on your beer at work to see if anyone was sipping while you are away!

 

[Chairman Cheyco]

You're pickin' up what I'm puttin' down.

I just wonder how they work. Weight limits, do they go to sleep, that sort of thing.

 

[Brewpastor]

A new project for some chipster to take on. If you figure it out, write it up and send it to BYO and maybe you'll get a t-shirt...

 

[Chairman Cheyco]

Actually, what I really want from them is one of the BYO oval stickers...

I was going to do this project using these because you can also control the temperature with them, but USB scales seem a little easier...

 

[nosnhojr]

You're pickin' up what I'm puttin' down.

I just wonder how they work. Weight limits, do they go to sleep, that sort of thing.

Yeah, this would be way cool! I'm concerned about the weight limit: we need a scale that goes to, what, 60 lbs? I'd be thrilled with 1oz precision, happy with 1/4 lb precision.

But my fridge is in the basement, so I need a tiny computer to serve the data. Best case would probably be a small linux box that collects and serves the data, perhaps just running apache.

An equally cool device would be a stand-alone scale that sits under each keg, has the tare weight programmed in, and displays remaining pints (rather than weight) on a simple lcd display. Maybe have the lcd detachable, so you can mount it above the taps on the outside of the fridge.

 

[Brewpastor]

Cool, and if they publish your project you'll get the sticker.

 

[nosnhojr]

Actually, what I really want from them is one of the BYO oval stickers...

I was going to do this project using these because you can also control the temperature with them, but USB scales seem a little easier...

That's so 80s. Gotta use the Java version.

 

[Brewpastor]

Yeah, this would be way cool! I'm concerned about the weight limit: we need a scale that goes to, what, 60 lbs? I'd be thrilled with 1oz precision, happy with 1/4 lb precision.

But my fridge is in the basement, so I need a tiny computer to serve the data. Best case would probably be a small linux box that collects and serves the data, perhaps just running apache.

An equally cool device would be a stand-alone scale that sits under each keg, has the tare weight programmed in, and displays remaining pints (rather than weight) on a simple lcd display. Maybe have the lcd detachable, so you can mount it above the taps on the outside of the fridge.

Let me be the first to volunteer to be your beta tester, I will need enough units to service 7 taps. Thanks.

 

[Chairman Cheyco]

But my fridge is in the basement, so I need a tiny computer to serve the data. Best case would probably be a small linux box that collects and serves the data, perhaps just running apache.

If you use a powered hub you should be able to run a really long cable. Or I wonder if you could trick a USB->ethernet print server. That way you could run as long a cable as you wanted for shure.

 

[Jester4176]

And you could have a little program set up to throw an alarm when you reach 1/2 - 1 gallon of beer left. Something audible with a "WARNING!!!! WARNING!!!!" being sounded.

 

[Truble]

if you wanted to do a little scripting, you could then collect historical data on deltas and track overall consumption times across different brews. You could run a little test, and invite a couple people over for beers. Show them the taps, and let them help themselves. see what is most popular.

I have a couple ideas for overcoming the weight limit too. you could build a "hammock" rig that the keg can stand in. the truss will take most of the weight, but allow some to be transferred through to the scale via a pressure plate below the truss. You could then calibrate it for full vs empty kegs, not the weight readings, and run a translation for the corresponding readings. Since the beer is uniform, a straight line "depreciation" of the weight should correspond to the amount of beer left.

You could use the same theory and mount a device to the top of the keg with a treaded rod "outrigger" that runs parallel to the keg down to the base. you could set the pressure that the rod exerts by using a threaded cap, and then use the same calibration techniques.

just a couple quick thoughts.

 

[Chairman Cheyco]

This is beginning to take shape...

 

[david_42]

If you calibrate in pints, don't forget to compensate for the CO2 in the headspace.

 

[Chairman Cheyco]

You mean the wieght of the CO2? I think we'd be able to neglect that...

 

[Baron von BeeGee]

You need one of these:
http://www.wisair.com/products/reference-designs/wireless-usb-hub/
No idea how much they are, though...

 

[Chairman Cheyco]

Oooo, gadget porn... on a Sunday, no less!

 

[Baron von BeeGee]

I have to take it whenever I can get it...

 

[Truble]

You need one of these:
http://www.wisair.com/products/reference-designs/wireless-usb-hub/
No idea how much they are, though...

daddy like.

 

[Baron von BeeGee]

daddy like.

Yeah, I have no idea how they work but they claim not to interfer with wifi or Bluetooth. Has the same range as normal Bluetooth, but doesn't say it is Bluetooth.

 

[MadWeezel]

Basic stamps are great and all but something a bit cheaper is Arduino. Spark Fun Electronics has the complete dev board @ $32. I got one a week ago and have been playing around abit.