iSpindel Digital Hydrometer

Mine does this too, so I'm interested in what people say

 

What have you got the iSpindel setup with for reporting and what firmware version are you running? It sounds like an issue with wifi reception, less likely would be the polynomial not working - I would however expect this to be persistent, not intermittent. I'm not sure if it's too late or not, however, it'd be interesting to see results of the iSpindel in closer proximity to the wifi router it is connecting to. Either just sitting on it's side or in a small bucket of water. This would help rule out the reception issue and point towards something else.

 

Ive got it linked with Brewers Chronicle.

I think the initial problem of intermittent gravity readings might have be a Brewers Chronicle thing - because I it was actually getting the reading every 15 minutes but only storing the temp.

That seems to have resolved itself and Im getting regular temp and gravity readings. But I reckon I need to recalibrate my iSpindel.

I had it calibrated perfectly - but just before I put it into the fermenter I dropped it on the bench. Only a small knock - but in hindsight enough to make the board slide further into the tube and muck up the calibration. Which will mean the polynomial is out of whack.

My initial reading should have been 1.055 but iSpindel had it at 1.010
Since it started getting regular readings it has been going in reverse as fermentation progressed. SG has increased????



I think in fairness to iSpindel my issues are user error. I just need write the first ferment off as a learning experience and be more careful next time

 

I saw a few comments earlier about offset calibration. The offset calibration isn't always necessary. If you have calibrated the iSpindel correctly at the right degree from the start, you should be right to continue using it.

I can see an open issue with calibration offsets not saving, looks like someone has rail-roaded it a little but it is still open from the OP:
https://github.com/universam1/iSpindel/issues/275

I find my iSpindels are either dead on or maybe 1 point out. They aren't generally meant to use as an absolute measurement, they are however a very good guide of fermentation and help with identifying D-rest time and when fermentation is complete.

 

Nah it doesn't work without doing the offset calibration, it doesn't reach a usable range no matter what angle you hold. Without calibration it shows ~16° at vertical and no matter what angle you hold it you can't get it less than 16°. There is speculation that it is bad memory on the wemos, or not enough delay to correctly write the memory. I've tried flashing various versions and still no joy. The issue has only been resolved by OP by swapping the wemos board.

 

16° vertical will cause issues, you're right.

Seems a bit drastic having to change the whole wemos board. I'd first look at the assembly of the gyro to make sure it's square on the pins and parallel correctly with the main PCB. I ended up having a very bad batch of gyros at one stage, showing 20-40° vertical and 50-60° laying flat. I had to do a tonne of testing for each build before I found another manufacturer. Out of curiosity, was this a pre-built or kit I provided?

 

I previously checked the gyro board to check it was square and parallel, also checked all connections with a multimeter. Yes it was one of your pre-built ones so the solder points were perfect, can't fault the quality of your assembly, must be the underlying hardware.

 

yep, you are right: if calibrated correctly then no need for offset. But it's necessary if you drop it on the bench just prior to ferment and don't have time to calibrate again.

I like the idea of being able to externally adjust values coming from the iSpindel without having to crack the fermentor open, and then the tube to put iSpindel into config mode.

I've actually made the database and API adjustments, and am currently using it on a ferment now.

Will make the website UI adjustments over the weekend.

 

@NoClue2Brew: sorry, I missed your post. Tag me next time so I get notified. Type the @ symbol and then start typing my name. It should pop up a list to choose from.

Did you end up sorting your problems out? What is your BC username and I can have a look at the database values. They will reflect the website though, so I don't think that will provide any clues. Maybe I can add API audit trail so user can review raw values coming in

 

The offset calibration issues doesn't relate to movement of the board in the tube, it relates to resetting the calibration after a power cycle as documented on the github issue. No amount of calibration can make it work after the power cycle.

 

Okay, I don't know how that got through my testing in that case. I've just sent you a PM, keen to sort it out for you. It's a shame the offset doesn't work as intended after a power cycle. Are you able to paste the URL in the browser address bar after you to go save it in a PM to me? Just remove your wifi password and other things. I may or may not be able to sort you out with a firmware version with the offset built into it.

 

My Ispindel seemed to work fine for the first 2-3 brews I did. But Ive noticed lately that its always way out. I performed a guided calibration with sugar and water when I first started using it. And I always calibrate it at 90 degrees at the start of each brew and check it by lying it vertical where it reads around .89-1.1 degrees and 89.XX degrees horizontal. So close enough.

But tonight its reading 1.040 when the actual gravity is 1.062 which is a fair way out.

 

If you're able to, try another reporting tool like Brewspy.

 

Planning on building a couple of new iSpindels, and i see things have come along a fair bit since the earlier versions. So a couple of questions.

1. Are we still using the same cylinders, and is there a source for them in Australia?
2. I take it that the CherryPhilip PCB version is now the preferred option, or is there something else on the horizon?

 

The change to the Cherry Philip PCB reduces the Petling from XXL to XL

Definitely, it's much more simple, compact and doesn't require 3D printed parts. There are a few, more commercialised designed, kicking around. These have pre-completed SMD parts just to help speed the build process up. Ultimately, the same skills are required as far as firmware handling, calibration and some soldering.

There are probably a few people in Aus who are providing parts, complete kits and pre-builds. I definitely do and likely won't stop anytime soon as there's a decent demand. Depending on the model you're looking at $35-$45 for the kit, $20 if you want me to fully build and test and postage on top which is between $9-$12. I'm certainly not in it for the money, just keen to make them accessible to folk from varied degree of technical experience and equipment availability.