Keg Scale and Digital Tap List project

[megabyte]

Have a print out with a QR code (much cheaper and easier than configuring an NFC tag).
once they download the app, they can scan the second QR code that will log them into that 'event'

Hey if users have a tablet sitting on their fridge (like I did) I could fit a "download the app" QR code on the screen and generate one for the event too. No stickers, no NFC? I love the idea.

 

[n87]

someone has likely written up a decoder that you would be able to buy and add into your program. this would be the easiest, and possibly even the cheapest in the long run.
Given you would likely only want QR, it wouldnt be much of a code (compared to a full decoder of common barcode symbologies)

http://iphonenativeapp.blogspot.com.au/2011/07/qr-code-readerscanner-for-iphone-app-in.html

 

[MHB]

The 1 part of 1.010 isn't measuring anything it is just saying times the equivalent mass of water.
For example if you were working out apparent attenuation on a beer 1.050 to 1.010, you cant go (1.050-1.010)/1.050 =0.0381*100=3.81%
The answer is actually (50-10/50)*100=80% or in Plato,(12.5-2.5/12.5)*100=80%

For your example it would be 20/6=3.33333*100= 333% error. 1.020/1.006 has no meaning mathematically
Use points or oP if you want a workable answer.

The quadratic Equation I mentioned was for converting from SG to oP the short form above is linear, the true conversion is exponential but the maximum error in the range between 1.000 and 1.100 is pretty small around 0.0008 so if that level of precision isn't needed don't worry about it.
If your precision isn't in the sub 1g range it is only of academic interest; down to your load cells I suppose.

Not trying to nit pick, but know from experience that small errors can grow out of proportion by the end.
Mark

 

[megabyte]

Awesome, thanks MHB. Yep I'd rather know about the small errors now rather than 6 months down the line when the test procedures are giving wacky results.

Hey I'm surprised (relieved) that nobody has asked about different keg sizes yet. So far I'm designing for cornie kegs using a 21cm diameter scale, but I was wondering if there are other keg sizes that are growing in popularity (like those european ones with bags in them) that people are using. Obviously CUB kegs could be a little difficult to cater for.

 

[n87]

Awesome, thanks MHB. Yep I'd rather know about the small errors now rather than 6 months down the line when the test procedures are giving wacky results.

Hey I'm surprised (relieved) that nobody has asked about different keg sizes yet. So far I'm designing for cornie kegs using a 21cm diameter scale, but I was wondering if there are other keg sizes that are growing in popularity (like those european ones with bags in them) that people are using. Obviously CUB kegs could be a little difficult to cater for.

eh... for a bigger keg, they just need a circle of wood or something to extend the platter, then add that to the weight of the keg, or tare it.
as long as its centred, and your scales cope with the 60+ kg (being bathroom scales, I would hope so)

 

[Frothy1]

Bluetooth can be buggy and frustrating when it wont connect.

With my igrill it will troubleshoot and give you a "restart bluetooth" option that works, even tho I may have restarted my phone and bluetooth already.

I dont know the brains behind why, when the igrill app restarts it, it works, but it does.

 

[trhr]

Michael,

Great idea and follow through with the prototypes, I'll be watching with interest for when we can purchase this in some form.
Many thanks for dumbing down your initial post for the Average Joe such as myself.

You have now joined the rarefied air of Husky and MHB in my books.
I read their posts.... I know I love what they're making... but I have no f@3kin idea how/why/when.... and also leaves me thinking "I'm pretty sure that also sends emails?" often with a headache and concluded Neanderthal statement of "Me love beer!"

 

[MastersBrewery]

Mytton rod are 22 and pin lock 22.5 but a plate of timber cut to size would fix size anomalies right quick.

 

[Moad]

I think you will do very well if you commercialise this into an all in one kit. Make it modular so you simply add another scale kit for additional kegs.

Another branch in the project I'd be interested in seeing would be to pour from the app too. Select glass size, hit pour. That way it could be locked down with an RFID tag or other method of authentication, you could restrict your housemate to a few beers a day while you were gone etc.

The keg level would be great and you'd have my money, my other suggestions are more of an interest from the tech perspective and not all that practical I guess...

 

[blekk]

Another branch in the project I'd be interested in seeing would be to pour from the app too. Select glass size, hit pour. That way it could be locked down with an RFID tag or other method of authentication, you could restrict your housemate to a few beers a day while you were gone etc.
..

In theory would be pretty easy to do using a normally closed solenoid valve and receiver not sure about the programming side of things though.

 

[DJ_L3ThAL]

One 'addon' to the system could also be a CO2 bottle scale to measure the weight and track how close you are to finishing the gas. I know once the liquid CO2 is finished the high gauge starts dropping but sometimes this is too late, it's the weekend and now you're going to run outta gas for your party... Be nice to be able to 'predict' when the liquid is almost out. I currently manually weigh my bottle every few months which is fine. But automatic technology rules...

 

[MastersBrewery]

The issue with inline valves, flow meters and the like is the inline device can create foaming and you won't know until you try. When the original 'kegbot' forums were going ball valves were the valve of choice. Solenoid valves were found to cause foam issues. Note neither are in the easy to clean category. Also know that the spaghetti in you kegger will be a little wild. Tips: the closer to the coupler the device is placed the better ( particularly flow meters). A valve directly on the rear of a shank will effectively isolate it from cooled liquid, so first pours would be crapier than some have now.

Put a lock on the kegger door, remove the liquid disconnect and lock the door problem solved.

 

[klangers]

Yeah standard solenoid valves aren't a good choice for beer - they have a very small orifice and this will cause massive pressure drops and hence foaming. And yes - very large pipe hammer from instant closing which may make rather unsettling noises to those not used to it. Any valve or tap kind of needs to be mounted near the spout, unless you want your whole beer line exposed to the (unclean) elements and heaps of dripping as the beer drains out of the line.

You'd be better off rigging an external solenoid to an existing tap I reckon.

Ball valves aren't sanitary either, and have the additional problem of possibly being buggered if frozen when shut (expanding water/beer trapped in the ball).

Either way, at various sporting venues, there are beer auto-pourers. It may be worth, if you're willing to line up for a XXXX, checking out how these machines work as they've probably already solved 99% of the above issues.

As an aside, I would really like a simple, cheap set of remote isolation valves to enable me to isolate my kegs without opening my keezer. This would give me peace of mind when I'm away - I've already had a hose pop off the shank and lost a whole keg to the carpet! A simple font-mounted switch would then de-isolate the pouring taps, ready to go.

 

[MastersBrewery]

If we were all using commercial couplers I'd be more confident with a motorised ball valve using snaplocks for issolation. Ball lock connections just aren't anywhere near as solid.

Klangers, the valve idea was issolation only, ie not to pour.

 

[megabyte]

One 'addon' to the system could also be a CO2 bottle scale to measure the weight and track how close you are to finishing the gas. I know once the liquid CO2 is finished the high gauge starts dropping but sometimes this is too late, it's the weekend and now you're going to run outta gas for your party... Be nice to be able to 'predict' when the liquid is almost out. I currently manually weigh my bottle every few months which is fine. But automatic technology rules...

I get that too, when the pressure starts to drop you're already too low to carbonate or dispense much beer over the weekend. I started a brainstorming thread about CO2 leak detection recently and considering the cost of CO2 sensors, monitoring the CO2 bottle's weight might be a viable option if it had a WiFi bridge so it could guarantee getting notifications to your phone.

 

[MastersBrewery]

1. Will taps be idependant of kegs being weighed. So 3 tap kegger holding 5 kegs with 2 in reserve/conditioning, but all 5 on scales able to be selected as ontap.

2 would something like an esp8226 with hc06 bluetooth module do the trick?

 

[megabyte]

1. Currently you can label each keg as "Tap 1" or "Spare" or "Cellar" etc. You can also display beers not being weighed too like "Esky". Let me know if there's any problem with that, it's pretty flexible at the moment.

2. Do you mean on the scales or as a separate bridge? I like the ESP8266 but my reservation about WiFi on the scales is the increased power usage. It necessitates much bigger battery systems (usually Li+ or LiFe) which cost more and they're a logistical nightmare to ship globally. I also don't like that you'd have to recharge the batteries each month or so, or run a power cord that adds to cable clutter. BLE just makes a lot of sense for the scales.

The HC06 is a Bluetooth serial port and iOS doesn't support the Serial Port Profile (thanks a lot apple! :angry: ).

We might end up with a BLE/WiFi bridge later on and for that we could use ESP8266 for the WiFi side but it will come down to certification costs and reliability. I know the ESP8266 can get FCC these days, but it might be cheaper to work with the bigger brands. Also I feel that the Broadcom or TI chipsets may be a little more reliable. At least that's the word from the engineers at particle.io.

Keep the suggestions rolling

 

[Frothy1]

For me, if it's not designed to be moved while in use, I like it to have a permanent power supply.

It would be good if it had a secondary power option.

 

[contrarian]

Hi Michael, great to hear that this project is moving along and sounds like a fantastic way to make it work.

The considerations I would have would be in relation to the durability of the scales. I use a chest freezer to serve from so it means lifting full kegs into the fridge, would the scales hold up to a keg being dropped or placed in a bit roughly?

I would also worry about how the electronics would hold up in a very damp environment. There is always some condensation but I must admit to having had he occasional beer leak where I have lost a few litres into the bottom so it would be handy to have scales that could cope with the moisture if that's a possibility.

It's always annoying when kegs blow together, I think the worst I have experienced was 3 in 3 pours so would be awesome to be able to know when it is coming or when you were down to the point where it was time to run off a growler and hook up a new keg!

 

[MastersBrewery]

Yeah I was thinking bridge. And on that point the bridge will be limited by the number of devices that can connect. The best BT4.0 bridge I could find only did 7 slave devices and that was to ethernet. I can't remember if BT 4.x has a built in hard limit of 7 or not.
It may be that a software bridge within the app being the simplest solution. Though would require a dedicated tablet/phone to be near the kegger.