Flite - Keg Level, Temperature, and Pressure Sensor

[LBussy]

We've all been there. I mean, I was chasing a bug for a couple of months in my current project - to find out it didn't exist.

 

[CDCTx]

We've all been there. I mean, I was chasing a bug for a couple of months in my current project - to find out it didn't exist.

Hah, I would ask if this was a white whale situation, but I think there actually was a whale in that story.

 

[LBussy]

This one literally ended up being "gas." Long story, for another project.

 

[UncleD]

Have you guys done anything to use and or certify that you use food grade plastic in the enclosure? It sounds like most people on this thread don't seem to care about that, but if you ever want wide distribution you will have to get some sort of certification that the plastic is of food grade quality.

This is designed to be a DIY, no certification has been done on the plastic, it will be whatever 3D printed plastic is used. If someone wanted to turn this into a viable product for wide distribution, I'd be happy to help! A food safe injection-molded to stainless steel lid with integrated housing for sensor electronics would be the next best step for this project.

 

[UncleD]

He's either working or golfing, I'm sure @UncleD will be around sooner or later with another idea.

Actually none of those believe it or not... Just got home from the hospital, with my wife and our first baby boy! Sorry for the delay in support, thanks for helping out @LBussy!

@backwoodsdistiller glad you got it figured out! Yes, that little dot on the pressure/temperature sensor indicates pin 1. Also, for future troubleshooting, you can load just the Arduino Flite library to test the sensor connection itself. The library can be downloaded here:

ARDUINO INTEGRATION | Flite

www.flitesense.com

 

[CDCTx]

@UncleD congrats!

 

[LBussy]

Just got home from the hospital, with my wife and our first baby boy!

Holy crap, congratulations! I guess that's a good enough excuse.

 

[UncleD]

Thanks everyone!

 

[backwoodsdistiller]

@UncleD Congratulations on your new baby boy.
Thank you for pointing out using the library.

 

[UncleD]

There have been requests to make the sensor update interval (averaging period for level readings) user-configurable. This has been implemented in version 1.5.0. This can be modified anywhere from 10-600 seconds.

Cheers!

 

[backwoodsdistiller]

If I upgrade the firmware to 1.5.0, do I need to recalibrate the levels and pressure?

 

[UncleD]

If I upgrade the firmware to 1.5.0, do I need to recalibrate the levels and pressure?

You do not. The calibration coefficients are stored in EEPROM, and won't be affected by this firmware update. By default the averaging interval will be 300 seconds after you update, so it will still behave as it did before, you just now have the option to modify the interval from the web GUI.

Cheers!

 

[Schauby7]

I love this idea. I have been struggling with trying to find the right solution to measure keg volumes in my 5-tap Keezer for years...I tried to use inexpensive flow meters but had trouble with foam, I also tried to build individual load cell platforms for each keg but had issues with reliability and weight drift.

When I stumbled across this idea I dove right in, constructed a couple Flite Lids as my own proof-of-concept and have not looked back since. I have built 8 lids to-date and all have been working flawlessly so far.

I took a slightly different approach to data integration, as I use a single esp8266 board with an I2C breakout to collect data from each of the 5 Flite Lids and relay the data to a self-hosted database. I opted to go without Temperature and Pressure as these measurements were not needed in my case.

I also integrated a CO2 Sensor into the same solution to monitor and be alerted of any CO2 leaks that may occur as slow leaks have drained too many CO2 tanks in the past.

Overall I love the simplicity of this design, and appreciate the open nature of the project, as well as the support and documentation available.

 

[LBussy]

That's an awesome implementation!

 

[Fr8Dog]

I like to hear more about the CO2 sensor.

 

[UncleD]

Wow, great job @Schauby7! I'm glad this is a good solution for you. I am curious to know, what you did for the temp and CO2? Did you build 1 lid with those, and the other's without? Or are they just separate sensors in the keezer? Great pics as well!!

 

[Schauby7]

For CO2/Temperature measurement I use an MH-Z19 sensor. It fits within the project box along with the esp8266 and I2C breakout board. The project box then sits within the Keezer in order to monitor CO2 concentrations of the enclosed keezer environment. I printed some small holes in the lid of the project box to allow airflow to circulate.

The MH-Z19 sensor can detect CO2 concentrations between 400-5000ppm, as well as ambient temperatures. It communicates with the esp8266 via UART Serial. I have software triggers configured to send myself an email when CO2 measurements exceed 4000ppm. I have discovered many CO2 leaks over the past couple years of using this sensor due to bad o-rings, leaky Pressure Relief Valves, and even a tiny pinhole in one of my corny kegs that only leaked when burst carbonating at 30psi.

Additional Info:
MH-Z19 CO2 Sensor

 

[garzlok]

For CO2/Temperature measurement I use an MH-Z19 sensor.

....just when I think I’m done tinkering, something comes along and pulls me back in!

 

[Nathan Graen]

I'm going to build one of these, but I'm not sure that the temp/pressure is worth the $38 that Digikey wants for it.

I understand that the whole thing is a really cool "unnecessary" gimmick, but do you guys really like seeing temp/pressure?

Will it work if I just don't wire it in?

 

[UncleD]

I'm going to build one of these, but I'm not sure that the temp/pressure is worth the $38 that Digikey wants for it.

I understand that the whole thing is a really cool "unnecessary" gimmick, but do you guys really like seeing temp/pressure?

Will it work if I just don't wire it in?

Yes, you can build a Flite lid with ONLY the time of flight sensor. It will still function without the integrated pressure/temperature sensor.

I went ahead and modified the 3D print for the sensor enclosure to omit the opening for the pressure/temperature sensor. You can download it here:

Flite Sensor Enclosure (Level Only) by JEDVentures

Flite sensor enclosure for a time of flight sensor ONLY

www.thingiverse.com

For wiring or programming support documentation check this page out:

SUPPORT | Flite

www.flitesense.com

If you have any questions, don't hesitate to reach out.

Cheers!

 

[DudeVee]

This looks like an awesome project. Where did you find the ZDSticky Epoxy? Currently I can only find 16oz kit on Amazon and it is clear. Was hoping to get larger capacity jugs to build 6 of these.

 

[UncleD]

This looks like an awesome project. Where did you find the ZDSticky Epoxy? Currently I can only find 16oz kit on Amazon and it is clear. Was hoping to get larger capacity jugs to build 6 of these.

I was able to find 2L parts on amazon, but it looks like they are out of stock at the moment. There are a handful of food grade epoxies out there. You can add a little food coloring when mixing if you want a color other than clear. Let me know if you have any other questions!

One piece of advice... I'd recommend building 1 first and making sure you have no issues during assembly or use. If something goes wrong, better to have it only happen to 1 instead of 6!

 

[morduno]

Quick question @Schauby7, have you experienced any issues with I2C over wires?

My application also requires a single controller for at least 3 different Flite sensors, but considering that I2C was not designed for long distance communication (in my case 5 - 10ft) I've been thinking of using RS232 or RS485 instead.

Thanks for the help and cheers for the project!

 

[Schauby7]

Quick question @Schauby7, have you experienced any issues with I2C over wires?

My application also requires a single controller for at least 3 different Flite sensors, but considering that I2C was not designed for long distance communication (in my case 5 - 10ft) I've been thinking of using RS232 or RS485 instead.

Thanks for the help and cheers for the project!

The longest cable I have from my main controller to a Flite Lid is roughly 5ft. I have not experienced any issues so far.

 

[morduno]

Thanks for the quick reply!

Understood, I will make some performance tests with straight I2C for the moment and if I notice anything then I'll try the RS232 approach.

Another thing, have you or anyone else had issues with condensation or corrosion in the wiring or connectors? I am at early development stages so I haven't had the chance to test myself, but in the past I've had issues like that when putting permanently powered electronics inside my keezer.

 

[LBussy]

in the past I've had issues like that when putting permanently powered electronics inside my keezer.

That's easy: Your stuff is working too long in between re-builds. Re-arrange and completely gut and replace your fermentation and serving chambers every 3 months and you will no longer have those issues.

Seriously though: Try a little dielectric grease?

 

[UncleD]

I've been using my same Flite lid for probably a year in my kegerator now, no issues.

 

[Jim Reidy]

Okay, finally completed the build on my 4'th keg sensor and headless controller. First 2 are in the keezer and working great. Monitoring via the app on my phone is easy and the features for alerts and trends work great. I have a Mango Milkshake IPA in the fermenter for the 3'rd keg set up and a Porter on deck for the 4'th. Thank you again UncleD for this great project. I'm not an electrical engineer or computer programer but i managed to put these together and make them work. I do have a couple questions/suggestions if anyone can help.
1) The flite temp sensor reads about 8F higher than the temp probe strapped about half way down the outside of the keg. Is there a way to enter a temp offset so the sensor could more closely show the temp lower in the keezer?
2) In addition to showing keg volume in either gallons or liters it would be nice if there was an option to show volume in pints. I know the math from gallons to pints is easy, but after 3 or 4 homebrews, well you know
Thanks again for the great project!!

 

[UncleD]

Okay, finally completed the build on my 4'th keg sensor and headless controller. First 2 are in the keezer and working great. Monitoring via the app on my phone is easy and the features for alerts and trends work great. I have a Mango Milkshake IPA in the fermenter for the 3'rd keg set up and a Porter on deck for the 4'th. Thank you again UncleD for this great project. I'm not an electrical engineer or computer programer but i managed to put these together and make them work. I do have a couple questions/suggestions if anyone can help.
1) The flite temp sensor reads about 8F higher than the temp probe strapped about half way down the outside of the keg. Is there a way to enter a temp offset so the sensor could more closely show the temp lower in the keezer?
2) In addition to showing keg volume in either gallons or liters it would be nice if there was an option to show volume in pints. I know the math from gallons to pints is easy, but after 3 or 4 homebrews, well you know
Thanks again for the great project!!

Hey @Jim Reidy !

Glad to hear this project is working well for you!

In regards to the temperature, I have not really considered adding an offset, because I would expect the temperature in a kegerator or keezer to be about the same around the entire keg. But I can imagine it being a little warmer at the top. I would be surprised by a difference of 8 Deg.F, that is significant. Have you tested and confirmed this temperature differential with another thermometer or temp sensor?

Cheers,
Uncle D

 

[LBussy]

I can see 8 degrees easily. Everyone should have a fan - always. It helps battle foaming among other things.

Without my fans on I can see 10 degrees difference in my keezer.

 

[morduno]

I can also confirm that I've experienced a considerable delta between the top and bottom of the keg. This delta gets more pronounced as the beer level starts to drop and the gap between liquid and the sensor increases.

 

[fuzzybee]

I've just kind of scanned the thread, but I didn't see anything about integration with RaspberryPints. Is there interest in this?

 

[UncleD]

I will definitely look to add a user-configurable offset for temperature in the next update, I didn't realize that there was such a significant discrepancy in temperature between the bottom and top of keg. Great feedback guys, thank you!

@fuzzybee I have not reached out to the RPints team. However the Flite controller has an API that can be leveraged by an IoT device like an RPi to get current information from the controller. Here's some more info:

REST API | Flite

www.flitesense.com

Also @Thorrak may be working on something along those lines

 

[fuzzybee]

I will definitely look to add a user-configurable offset for temperature in the next update, I didn't realize that there was such a significant discrepancy in temperature between the bottom and top of keg. Great feedback guys, thank you!

@fuzzybee I have not reached out to the RPints team. However the Flite controller has an API that can be leveraged by an IoT device like an RPi to get current information from the controller. Here's some more info:

REST API | Flite

www.flitesense.com

Also @Thorrak may be working on something along those lines

Sounds good! I'll keep an eye on all of this for my keezer-in-progress.

 

[mik3y]

I've just kind of scanned the thread, but I didn't see anything about integration with RaspberryPints. Is there interest in this?

If you're using Flite with Taplist.io and run in to any problems or ideas, just let me know. I worked with @UncleD a while back to make sure it integrated well, and I certainly want to keep it that way. (I haven't seen a lot of usage yet, but I don't know how complete flite's world takeover is.. yet!)

 

[UncleD]

If you're using Flite with Taplist.io and run in to any problems or ideas, just let me know. I worked with @UncleD a while back to make sure it integrated well, and I certainly want to keep it that way. (I haven't seen a lot of usage yet, but I don't know how complete flite's world takeover is.. yet!)

Thanks @mik3y! As far as world takeover goes... including my test user, I think there is 1 user using Flite with taplist.io

Did we ever get the pressure added as an "option" in the web settings? I know it's in the JSON object, but I don't think we ever added it to get displayed next to the temperature. I know Flite may be the only sensor that is also sending pressure, but some users may want to leverage that in your API.

Cheers!

 

[UncleD]

I have just released Flite 1.6.0 firmware, which can be loaded with BrewFlasher.

This update includes the ability to add a temperature offset and fixes a bug when calibrating level with the display when the displayed value is "nan".

Sorry for the delay in rolling this out. Between a newborn and a new puppy, I've got my hands full!

Cheers!

 

[LBussy]

What took you so long?!

 

[Jim Reidy]

Getting ready to update the firmware on my headless controllers to the new 1.6.0 release. From posts regarding previous firmware updates, it sounds like my existing calibration points won't be deleted during the update. Just want to verify before proceeding

 

[UncleD]

Getting ready to update the firmware on my headless controllers to the new 1.6.0 release. From posts regarding previous firmware updates, it sounds like my existing calibration points won't be deleted during the update. Just want to verify before proceeding

Correct, this will not erase your calibration.

Cheers!