iSpindle - DIY Electronic Hydrometer

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BreeBrew

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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.
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toadyus

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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

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@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

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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.
 
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LBussy

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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.
 
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LBussy

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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. :no:
 

ChrisThomas

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@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 :inbottle:
 

toadyus

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@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

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@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

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@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

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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'
 
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DuncB

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

 

ChrisThomas

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

James_42

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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.

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LBussy

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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

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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

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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?
 

ZeSlammy

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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?
Out of maybe 100 iSpindels I built so far, I had ONE pelting with a dent in the lid. They are otherwise pristine.

That being said, not sure it matters, it just means extra cleaning.
 

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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.

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I've been looking into this myself - have you considered rigid plastic pipes with push-fit caps/bungs bought separately? Looking at eBay I can get 30mm clear acrylic tubes with an inner diameter of 28mm (or 28mm with inner of 26mm). These can be cut to length by hand and the bottom end sealed with food-safe sealant. I know off-the-shelf containers would be ideal but if we're going to the effort of hand-soldering boards then a little bit of DIY doesn't seem too extreme!

In terms of general requirements for a container:
As far as I can see from the iSpindel bill of materials, the Wemos D1 is the widest part in the tube with at 25.6mm. Ignoring wiring/solder/supports and using a 18650 battery you get to a weight of about 70g inside the tube.

To get the tube to float it will need to hold at least ~70cm^3 (70ml) of air plus enough to offset the weight of the tube itself. The original Petling XL bottle holds 105cm^3 (105ml) so to be close to that a 28mm inner diameter tube would need to be ~170mm long and a 26mm inner diameter tube ~200mm long
 

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The syringe holder in my picture above was 190mm long, widest 40mm at the top and then 29 mm until the taper at the bottom. It floated with all of the bulbous bit above the wort line. Because it was long I was able to get the battery and all the electronics ( except wifi antenna and induction chargin loop ) low down in the bottle. This helped with the tilting moment as the higher the mass in tube it needs counterbalancing at the far end to get that 25 degrees. Perspex tubing I considered as well, seemed expensive ( and quite heavy ) but if it was internally threaded and a lid designed to screw in could be very good.
I await your design.
 

James_42

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I am interested too. Just be aware that although the widest component is the D1 mini, depending on how many parts you solder together and how you fit them together, you might need something a little wider. I have a little perf board that is exactly the same as the wemos d1 mini, but with the headers, accelerometer board, resistors, etc. it makes a sandwich that needs a wider tube than the D1 mini alone, which is why I was wondering which parts I could leave out.
 

DuncB

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You need all of the parts I think. But variance available for the sled and battery holder.
You can reduce the post heights so that you have less separation between the boards. Or just solder the posts in such a way that you can't take them apart. Not too much of a problem. This will reduce the width by a few mm.
 

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Hello everyone, I have a question related to flashing the d1 mini. I have built two ISpindels, both with the pcb from opensourcedistilling. Previously, both of my units were working/have been flashed, and I was able to connect to them via wifi. Original problem was with the gyroscope, receiving NaN values. I opted to swap out the gyroscope and as luck would have it, only one of the ISpindels will connect to wifi. My problem is in trying to flash the non working unit. When I power on the ISpindel, I see a solid blue light. After locating the firmware and pressing flash, the blue led blinks once and then turns off. It seems like the flash process is stalling. I can see in the nodemcu log that it says "Begin find ESP8266". I have also tried connecting it to Putty to see if I could find the problem, but it is just showing constantly refreshing gibberish. Battery is fully charged. Would some problem with the gyroscope completely throw off the boot process of the d1 mini? please help, I have been trying to build these for a few months now and have had individual problems with individual parts at each turn. :(
 

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So what is the situation on the one you are trying to flash ? All elements are presents ? You put in a new Gyro ?
Putty sends data to the serial port ? Gibberish means you might not have the proper speed to dialog with your iSpindel.
 

kpietro22

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@ZeSlammy all elements are correctly soldered. Both of them WERE working and transmitting WiFi before I swapped the gyros. Now that both of them have new gyros, only one will do WiFi. The other one shows a solid blue led when powered on. No matter how many times I press the reset button it stays solid.
 

ZeSlammy

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Have you tried changing the baud rate at which putty dialog with the "solid blue" one ?
You remove the battery when you soldered ? (Silly question but I fried one iSpindel not doing that )
 

kpietro22

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@ZeSlammy it was originally flashed with the most recent firmware at baud rate 115200. So in putty I switched it to the correct com port and respective baud rate. And yes I am certain that I removed the battery before soldering. Is there any line in the code that throws off the wemos startup if there is an issue with the gyro? I am trying to avoid buying a new wemos ad I know they take time to ship and I had this one connected to WiFi before ...
 
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