iSpindle - DIY Electronic Hydrometer

[James_42]

Another issue with the 50mL tube that I hadn't thought of until recently is buoyancy. I did a test with just the battery in a tube and it floated at the level of the cap. I need to study the math more but I'm guessing that's not going to let it tilt correctly. I'm not sure if a taller tube with the same diameter is available or if I can 3d print an extension to it.

Still a lot of work to do...

I am super interested in figuring out a version that fits in a 50ml centrifuge tube. The path I was going was to use a 18500 LiFePO4 cell, sold in hardware stores where I live for solar lights. They are still a decent sized cell, the one I have is 1000mAh, but small enough that they fit in a 50ml tube with a Wemos D1 mini or LOLIN32 Lite and a MPU6050 and still float at a reasonable looking angle. The project I built to go in it (rymes with Boaty) claims a year from a 3400mAh cell sending data every 10 minutes, so I assumed it would last long enough with the smaller battery, but my board was damaged and I haven't got to try it yet. The LiFePO4 cell has the advantage that it can power 3.3v boards directly, but it is harder to find chargers that work with it. I had planned to just take it out to charge it.

 

[ZeSlammy]

Is there a link for this board?

CHerryPhil Gyro might be the one cherryphilip74/iSpindel-PCB

 

[James_42]

I did see a Cherryphillip74 design for a 50ml tube, but the thread seem to have gone stale and for several reasons I'm not interested in custom PCB versions. Mainly I would like to use my 3d printer, but it also seems like a complicated, expensive and time consuming way to solder togther off the shelf components. I already have most or all of the components and just want to fit them into a smaller tube rather than start over.

I have been looking for an explanation of what the resistors and diode in the wiring diagrams I have seen do. If they are for the temperature sensor or a litihum ion battery, I would be very happy to leave them out and just have the D1 mini, MPU6050 and LiFePO4 battery.

 

[ZeSlammy]

I did see a Cherryphillip74 design for a 50ml tube, but the thread seem to have gone stale and for several reasons I'm not interested in custom PCB versions. Mainly I would like to use my 3d printer, but it also seems like a complicated, expensive and time consuming way to solder togther off the shelf components. I already have most or all of the components and just want to fit them into a smaller tube rather than start over.

I have been looking for an explanation of what the resistors and diode in the wiring diagrams I have seen do. If they are for the temperature sensor or a litihum ion battery, I would be very happy to leave them out and just have the D1 mini, MPU6050 and LiFePO4 battery.

Floaty is the way I think, with a 3D printed something.
Thing is you can't get an iSpindel working without the temp sensor I think

 

[ChrisThomas]

I did see a Cherryphillip74 design for a 50ml tube, but the thread seem to have gone stale and for several reasons I'm not interested in custom PCB versions. Mainly I would like to use my 3d printer, but it also seems like a complicated, expensive and time consuming way to solder togther off the shelf components. I already have most or all of the components and just want to fit them into a smaller tube rather than start over.

I have been looking for an explanation of what the resistors and diode in the wiring diagrams I have seen do. If they are for the temperature sensor or a litihum ion battery, I would be very happy to leave them out and just have the D1 mini, MPU6050 and LiFePO4 battery.

There are plenty of sites that discuss the electronics required to make the iSpindel work. Briefly, diode to stabalise the reset circuit, resistors pull up for the temperature sensor and voltage divider to allow the D1 mini to measure the battery voltage. The iSpindel won't complete the boot cycle if it doesn't find all of the hardware.

I've looked at making a very small iSpindel, smaller than the 50ml tube, but I cannot find a suitable tube, small enough to fit into (and out of) a 1 gallon demijohn. I've based it on a ESP12F and it works fine on the bench, I've even layed out a PCB in anticipation. It's more difficult to flash as it requires a separate USB to serial converter, but is straighforward.

 

[James_42]

Floaty is the way I think, with a 3D printed something.

Yes, the Floaty really is elegant, just two inexpensive boards and a battery. I have to order a new LOLIN32 Lite to give it another try.

While I wait I have a MPU6050, D1 mini and matching perf board, and even the temperature sensor, just not the charger or resistors, diode, or the ridiculously rare and expensive pelting. I can go without the charger I think, I can get the resistors locally, I have several of the 50ml centrifuge tubes, so it is just the diode I need to find. One source I looked at said you can use another resistor so I might try that.

I cannot find a suitable tube, small enough to fit into (and out of) a 1 gallon demijohn

Yes, I know what you mean. I do small batches and I just got a used glass drink dispenser that I am going to try to convert into a fermenter just so I can get a floating type hydrometer in.

 

[Lalo_uy]

Yes, the Floaty really is elegant, just two inexpensive boards and a battery. I have to order a new LOLIN32 Lite to give it another try.

While I wait I have a MPU6050, D1 mini and matching perf board, and even the temperature sensor, just not the charger or resistors, diode, or the ridiculously rare and expensive pelting. I can go without the charger I think, I can get the resistors locally, I have several of the 50ml centrifuge tubes, so it is just the diode I need to find. One source I looked at said you can use another resistor so I might try that.


Yes, I know what you mean. I do small batches and I just got a used glass drink dispenser that I am going to try to convert into a fermenter just so I can get a floating type hydrometer in.

Yes, you can put a 330 ohms resistor in place of the diode.
The main problem of not installing the temp sensor is the need to modify the software to skeep it, but is doable.

 

[LBussy]

Yes, the Floaty really is elegant

Indulge me, save me some scrollback, and tell me about (or link me to) information on the floaty?

 

[Bigdaddyale]

Indulge me, save me some scrollback, and tell me about (or link me to) information on the floaty?

https://www.diyhomebrewers.com/2020/09/floaty-wifi-hydrometer-montaje-y-como.html

 

[LBussy]

Thank you!

ETA: DLI don't fail me now!

 

[BreeBrew]

es, the Floaty really is elegant, just two inexpensive boards and a battery......

You think so? You also need a relatively expensive 3D printed sled. Regarding that the design of @Open Source Distilling is much more elegant, just a custom pcb, some parts a battery and a tube. And no lose wires, the battery is in a holder soldered to the PCB.

 

[ZeSlammy]

Indulge me, save me some scrollback, and tell me about (or link me to) information on the floaty?

This in English might be slightly more useful : Floaty hydrometer : Wireless Electronic Hydrometer & Thermometer

 

[DuncB]

I think the floaty is bluetooth, so not sure you can access it from everywhere that easily.

 

[toadyus]

There are plenty of sites that discuss the electronics required to make the iSpindel work. Briefly, diode to stabalise the reset circuit, resistors pull up for the temperature sensor and voltage divider to allow the D1 mini to measure the battery voltage. The iSpindel won't complete the boot cycle if it doesn't find all of the hardware.

I've looked at making a very small iSpindel, smaller than the 50ml tube, but I cannot find a suitable tube, small enough to fit into (and out of) a 1 gallon demijohn. I've based it on a ESP12F and it works fine on the bench, I've even layed out a PCB in anticipation. It's more difficult to flash as it requires a separate USB to serial converter, but is straighforward.

The electronics part is the easy part, getting it to be buoyant is the hard part. I've been working on a smaller sized unit that fits in a 2l preform or the containers that white labs used to sell yeast in and I am about to give up on the dream of a smaller ispindel.

 

[ChrisThomas]

@toadyus The float angle and behaviour was something that I am worried about, but as I can't find a suitable container I can't experiment with. You say you used a 2l preform? The 2l preforms I've looked at have on outside diameter almost the same at the inside diameter of my glass demi-johns so I've avoided. What are the dimensions of the preform you have?

 

[DuncB]

I found a container for 50ml syringes at work with a lid and a great shape. Spent ages fiddling and fitted the Ispindel in on a modified sled with an induction charging loop in the lid. It was a sealed never to open unit.

Unfortunately the LDPE container buckled during the pressure ferment badly, didn't leak but became laughably inaccurate. Very irritating.

I think the answer is to approach a university lab worker who makes glass for chemistry experiments.
Then get a glass tube made with a rigid screw on lid, build in an induction charge loop and it would be perfection especially if you could make it hydrometer shaped so that the antenna could go up the narrow bit. Narrow bit wouldn't need to be so long as on a hydrometer, but main gubbins below surface would increase accuracy a lot.

Overall I think the lid is the stumbling block, but if you could get a petling blank for say a 2Litre bottle you could potentially blow this to a long straight ish " bottle " that could be fitted with the parts.

I am still looking for an off the shelf container to complete this project.

 

[LBussy]

I think the floaty is bluetooth, so not sure you can access it from everywhere that easily.

I believe (only briefly reviewed) that the BT is used for initial setup and not for regular operation.

And again, after only the most cursory examination, I would be more inclined to trust the temperature sensor on the iSpindel as it is able to be positioned in a better place than the Floaty. I'm not sure if that's true or not.

 

[LBussy]

I think the answer is to approach a university lab worker who makes glass for chemistry experiments.

After all that, why not just buy a Tilt? Or at the very least a fermenter that has a wider opening? I mean, I like DIY and Open Source of course, but trying to fit, well, a large round peg into a small round hole is not going to work.

 

[ChrisThomas]

@LBussy Still going to keep my eye open for that smaller peg though. What else am I going to do in between ferments? Other than drink the result of my hard work of course

 

[toadyus]

@toadyus The float angle and behaviour was something that I am worried about, but as I can't find a suitable container I can't experiment with. You say you used a 2l preform? The 2l preforms I've looked at have on outside diameter almost the same at the inside diameter of my glass demi-johns so I've avoided. What are the dimensions of the preform you have?

The main body of the preform is 28.64 mm, but then it goes out a bit where the lid screws on this OD is 32.9 mm. The inside diameter is 20.69mm.
Here is what the preform looks like:

 

[ChrisThomas]

@toadyus That's the preform I've seen before. I've aslo tried centrifuge tubes but so far no luck. It may be that what I'm looking doesn't exist as an off the shelf component. It also maybe that if I do find a suitable tube that I won't be able to get it float right anyway, but I'll keep on looking.

 

[toadyus]

@toadyus That's the preform I've seen before. I've aslo tried centrifuge tubes but so far no luck. It may be that what I'm looking doesn't exist as an off the shelf component. It also maybe that if I do find a suitable tube that I won't be able to get it float right anyway, but I'll keep on looking.

I wish you all the luck in the world! Godspeed in finding a solution that's Buoyant!

 

[James_42]

You think so? You also need a relatively expensive 3D printed sled. Regarding that the design of @Open Source Distilling is much more elegant, just a custom pcb, some parts a battery and a tube. And no lose wires, the battery is in a holder soldered to the PCB.

Yes, I really do think so. That the floaty is more elegant, much much more so than the the iSpindel. Just two parts to solder together compared to many times that for an iSpindel. You can't really argue that the Floaty isn't more elegant, elegant in this case meaning more simple. If you don't have a 3d printer you need to either order a circuit board or 3d print and then you either need to solder 2 components together or, I've lost count 7 for the iSpindel? Also, you can probably get a friend to do a 3d print for you, or at least get it don locally, which probably isn't the case for a custom circuit board. The Floaty wins easily for being the more elegant of the two.

I assembled the floaty in a few minutes and it slides right into a 50ml tube, while I have had the pile of parts for an iSpindel for weeks while I try to figure out how to fit them together to do the same thing. Maybe if I leave out the temperature senor and modify the code - not straight forward at all. I am annoyed that both default to using the unobtanium preform that you need to order from Lithuania or something. Of course I already have a 3D printer so even if I was building an iSpindel in a preform I would still do a 3d printed version rather than the extra time and money of ordering a custom circuit board, which I still think is an unnecessarily complicated way of putting together off the shelf components.

For the record, I'm actually hoping to build both and it does look like the iSpindel has several advantages, not the least of which is a large user community, but also the fact that it is open source and you aren't locked into the developer's app or paid software.

I found a container for 50ml syringes at work with a lid and a great shape. Spent ages fiddling and fitted the Ispindel in on a modified sled with an induction charging loop in the lid. It was a sealed never to open unit.

Unfortunately the LDPE container buckled during the pressure ferment badly, didn't leak but became laughably inaccurate. Very irritating.

Do you mean a 50ml centrifuge tube or actually a 50ml syringe? How did it buckle? Was it a temperature change? The centrifuge tubes are easy for me to get. I already had one and asked a friend who works in a lab and she gave me a handful for free. The certainly aren't as rigid as a preform, but I'm surprised they would buckle. Luckily I don't like lager so would usually be fermenting close to the temperature I assemble the hydrometer at

edit - oh sorry, rereading I see it was a 'container for a 50ml syringe'

 

[DuncB]

I meant a container that the 50ml syringe comes in. You Crack off the lid and remove the sterile syringe and they chuck away the container.

Picture below. It was a good shape, components fitted in well and the antenna was well above the ferment which was an issue with the 3 d sled version I was using for the standard petlings.

But it was too flimsy and deformed from a circular cross section to triangular under the 15 psi or so of pressure ferment.

My intention was not to have an Ispindel small enough to fit thru narrow openings but to have a sealed, stable ispindel with less cleaning worries, better antenna utilisation and using a readily available for me and free container. Otherwise I'm very happy with the ispindel and if I could find a rigid lid so it didn't deform under pressure I'd be even happier.


Perhaps this device might be suitable ? I have no experience and haven't looked for any reviews.

https://www.kegland.com.au/rapt-pill-hydrometer-thermometer-wifi-bluetooth.html

 

[ChrisThomas]

Hmmm, that container for the RAPT Pill looks interesting. I wonder if I can find a source and in the right size?

 

[DuncB]

Let me know if you do.

 

[James_42]

I meant a container that the 50ml syringe comes in. You Crack off the lid and remove the sterile syringe and they chuck away the container.

Picture below. It was a good shape, components fitted in well and the antenna was well above the ferment which was an issue with the 3 d sled version I was using for the standard petlings.

But it was too flimsy and deformed from a circular cross section to triangular under the 15 psi or so of pressure ferment.

Thanks. I have also spent a lot of time looking for a suitable, affordable, easily obtainable container and the 50ml centrifuge tube is the best option I have found so far. There are 100ml tubes on Amazon, but they have metal caps that don't look like I want them in my beer and you usually have to buy a bunch of them making them not too cost effective when you only want a couple and aren't sure if they will work. I have one that a non-food product came in and if I can find a plastic cap that fits it I might give it a try. The RAPT Pill container looks interesting, but I imagine, like the Tilt is is custom for them. It is getting close to a tempting price.

 

[LBussy]

The Floaty seems nice, and I think it's great that they allow DIY. I am concerned about the closed source, and the need to use their cloud services. I don't know if I'd call that "elegant." If you are DIYing, the options for the iSpindel are adequate and effective, and it's well supported by the other tools in the ecosystem.

 

[James_42]

The Floaty seems nice, and I think it's great that they allow DIY. I am concerned about the closed source, and the need to use their cloud services. I don't know if I'd call that "elegant." If you are DIYing, the options for the iSpindel are adequate and effective, and it's well supported by the other tools in the ecosystem.

I might be using "elegant" in a way people aren't familiar with. In the scientific community an elegant experiment is a simple one and the Floaty is much simpler than an iSpindel. I don't necessarily think it is the best option, as I mentioned, I am trying to build both. I do have some similar concerns. It seems kind of like a Apple vs PC or Android type thing ... I appreciate apple products, but use PCs and android phones.

 

[fermint]

Howdy. I received some peltings/preforms to build some iSpindels but the majority have scuffs or scratches on them. The vendor indicates these are normal, is that what others have found?