iSpindel - digital WiFi hydrometer

[Isolec82]

My Ispindel is up and running now. I calibrated it in bitter. Has any one bothered to calibrate it for both top and bottom fermenting beers. I am sort of thinking that the krausen is quite different for lager and bitter styles or am i just over thinking this!

 

[SteveH]

I just built one of these but not yet calibrated it, be interested to hear how you get on!

 

[Isolec82]

I built this back in October. At the time i was making cider so calibrated it in a cider. When i then went to use in a beer, it was miles out. I put this down to the fact that there was no krausen to have an effect on it. Have recently re-calibrated in a bitter but hence my question as to whether there would be a difference in a top fermenting brew over a bottom one. I may need to swap one of the resistors for a diode as i sometimes have a job to wake it. My brew shed is in the garden and although not far, i have had to convert an old router to a wifi extender in order for it to talk when inside the brew fridge.

 

[pottsworth]

I bought the kit from 3D mechatronics and assembled it. All good apart from the very specific orientation instruction for the battery connector that turned out to be wrong (checked colour against pcb marking too late), and ended up with a fried charger board and temp sensor. I also assumed the Wemos would come pre-flashed, as the kit implied it just needed to be soldered together, but it wasn’t, which turned out to be a bit of a challenge with a Mac. Sorted it after a couple of nights of reading through the small number of articles about flashing Wemos via Mac.

Mines in its first brew. I only calibrated it in sugar water. So far the numbers seem sensible, although I didn’t put it in until 24 hours in, so didn’t manage to compare to OG.

Mine did stop communicating with wifi after 4 hours, but a battery charge sorted it. What voltage range do other people go down to?

Also are you guys using ubidots or something else? If I get a second Spindel, even the education version will be a few quid a month.

 

[LeeH]

I’m having some bother getting mine to read SG, hopefully someone on here can help. I’ll post up my issue over the weekend.

 

[Isolec82]

Hi pottsworth, i too built a 3d mechatronics one and it was all fine other than the flashing of the software. For some reason it wouldnt - load after scores of attempts, i tried an earlier version and it loaded. After that i was able easily to ugrade to the latest. I am mid calibration at the moment and Ubidots has not updated for 5 hours now - getting worried. Ispindel is flashing as tho' talking, internet is ok. Wait and see if Ubidots has updated in the morning. Hi LeeH if you use Ubidots create a variable with the following function - "round((1+gravity/(258.6-227.1*gravity/258.2))*1000,0)".

 

[pottsworth]

I am mid calibration at the moment and Ubidots has not updated for 5 hours now - getting worried. Ispindel is flashing as tho' talking, internet is ok.

Sounds like what mine did - charging the battery fixed it.

For calibration I pressed the reset button a few times then connected to the ispindel hotspot. One of the menus in there gives you a live reading of angle so you don't need to wait for ubidots

 

[Isolec82]

Ive just noticed it is reporting a rssi of -80 dBm. So it is not getting a good signal. Moved the router and have it talking again. Perhaps i should've connect direct to the spindel for calibration - one less thing to go wrong!

 

[Isolec82]

Does anyone who understands these thing reckon this graph looks ok? It is over 40 years since i did any serious maths. This my 3rd attempt at calibration and i just cannot seem to get it right! If you extrapolate the curve on down it would appear to have a value of 4 plato for pure water and this seems to be a large divergence.

 

[pottsworth]

I used the online calibrator, as it gave a formula for SG instead of plato - maybe worth putting the values you already have from the excel sheet into here and seeing if you get something more usable?

http://www.ispindel.de/tools/calibration/calibration.htm

 

[Isolec82]

I will give it a go and report back.

 

[Isolec82]

I assume it is the degree 2 value that is put into the ispinel. What is the degree 3?

 

[Isolec82]

That's better. Reasonable readings now. Brew an Octoberfest tomorrow and try it in anger. Just need to work out how to integrate the ispindle temp reading into a brewpi for a fermentation controller - Next week!!

 

[pottsworth]

I used the degree three one in the setup page on the ispindel (where you put your WiFi details in)

From memory you need to change all of the “x”s to “tilt”, and add multiply signs (*) between the number and tilt^3.

Alternatively you can just leave the setting on the Spindel and do it all in ubidots with a derived variable.

I was thinking of trying to setup a temperature controller using the ispindel, but I seem to get quite a bit of noise (~0.5c) even when the temperature is stable, so I don’t know how well it would actually work. I currently have an inkbird with the sensor in a thermowell, so I doubt anything would be much more accurate than that.

 

[jarnold]

I built something simlar a while back. It talks to my homebrewed homebrew temp controller, which then talks to google sheets(the signal can't make it through the liquid and the fridge all the way to my WiFi router)

Used one of these:
http://rover.ebay.com/rover/1/710-5...0001&campid=5338413729&icep_item=322043138669
I haven't ever calibrated it, on the grounds that I was more interested in seeing when the gravity stopped changing.
Anyway, pretty much every time I use it, my graph starts by rising fairly rapidly, then levels out and starts falling slowly.
I am at a loss to understand this. I've checked that the PCB with the accelerometer can't go past vertical. My guess is that it's the foam on top of the brew, although I've read that this should not be a problem. I'm thinking that the screw cap, being somewhat larger in diameter than the tube, is affected by the foam. I may try putting the thing together such that the screw cap is at the bottom - see what happens - I'm pretty certain that it seals well, as when I unscrew the lid to recharge, I get a tiny hiss, as the pressure equalizes(not sure which directio, or why, but it's consistent).

 

[pottsworth]

I built something simlar a while back. It talks to my homebrewed homebrew temp controller, which then talks to google sheets(the signal can't make it through the liquid and the fridge all the way to my WiFi router)

Used one of these:
http://rover.ebay.com/rover/1/710-5...0001&campid=5338413729&icep_item=322043138669
I haven't ever calibrated it, on the grounds that I was more interested in seeing when the gravity stopped changing.
Anyway, pretty much every time I use it, my graph starts by rising fairly rapidly, then levels out and starts falling slowly.
I am at a loss to understand this. I've checked that the PCB with the accelerometer can't go past vertical. My guess is that it's the foam on top of the brew, although I've read that this should not be a problem. I'm thinking that the screw cap, being somewhat larger in diameter than the tube, is affected by the foam. I may try putting the thing together such that the screw cap is at the bottom - see what happens - I'm pretty certain that it seals well, as when I unscrew the lid to recharge, I get a tiny hiss, as the pressure equalizes(not sure which directio, or why, but it's consistent).

What sort of range of angles are you getting?

My last batch went from about 62 degrees at 1.045 to 33 degrees at 1.012

 

[jarnold]

Wow! I usually get a range of about 75 to 85, so I probably need to do some adjustment to the centre of gravity or something.
Trouble is, there's not a lot of headroom in my fermenter bucket when it's got 40 pints in it.

 

[pottsworth]

I had to add about 20g/30g of ballast to mine to get it to that range. From memory I think the guidance was to aim for an angle of ~25 in clear water.

 

[jarnold]

OK, Thanks for that. I'll make a few adjustment before the next brew.

 

[Isolec82]

I used 2*2p coins to balance mine. Cant remember what the weight but is easily checked. It is also necessary to give it a horizontal reference. I hadn't realised until recently. You have to set horizontally and do a different calibrate - taking care that the lip below the screwtop doesn't allow it to sit at an angle - i used spacers.

CO2 Bubbles do adhere to the case when fermenting and this must affect the angle and cause the change you see. I dont think flipping it over would help indeed it may make it worse as there is then a greater mass for the bubbles to collect upon.

I notice that on first putting the spindel in, it does read a couple of points higher compared to both my Hydrometer and Refractometer readings. However i guess that once the bubbles form it corrects this. It does say in the guide that more accurate calibration is made in a real brew. I also notice that yeast from the krausen sticks and must affect the reading. My gut reaction is that the readings will only be indicative and never absolute, and probably that is all we need!