iSpindel - digital WiFi hydrometer

The Homebrew Forum

Help Support The Homebrew Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
Hi,

I'm hoping someone can help me with the Plato Formula. I don't have a full MS Excel copy so can't get the macro to work. Could someone plug the following measurements in and post the formula?

S.G. Tilt
1.000 24.8
1.010 25.7
1.012 26.37
1.016 27.6
1.018 29.3
1.022 30.9
1.026 33.1
1.032 35.8
1.038 39.2
1.046 42.8
1.068 56.1
1.090 64.3

Many thanks!
You could do it in Google Sheets (free)
 
I added a Trenline and its equation is SG = 0.00205*TILT + 0.957

1598948966304.png
 
For my iSpindel, I got a third-order polynomial

2.4950708612059392E-6tilt^3
-3.597130446990714E-4tilt^2
+ 0.018498247948015193tilt
+ 0.6946119873729901
 
What is the 3rd-order polynomial you got? I suspect it's almost linear. It will be if the second and third orders are very small. What about the questions I asked earlier? wink...
 
There is a screen shot of my result above. You'll have to excuse me, I didn't realise the other posts were questions. I'm not sure how to answer them.
 
I thought I had asked you whether you took your measurements at the same temperature each time and whether you corrected them for temperature? I can't find those questions in my post so I must not have posted them, my bad.

My iSpindel does not report Plato any more - I set it to report Gravity in the configuration. Or it happened when I entered the equation in the iSpindel configuration.

Have you done this? iSpindle Documentation

Water should give zero degrees Plato = no sugars
 
Last edited:
I thought I had asked you whether you took your measurements at the same temperature each time and whether you corrected them for temperature? I can't find those questions in my post so I must not have posted them, my bad.

My iSpindel does not report Plato any more - I set it to report Gravity in the configuration. Or it happened when I entered the equation in the iSpindel configuration.

Have you done this? iSpindle Documentation

Water should give zero degrees Plato = no sugars

Yep, followed the calibration procedure. Made up a sugar solution and brought it back to room temp, used room temp water to dilute it to get the OG reading.
 
If Ubidots is giving Plato you need to do config again, maybe you entered the equation in a wrong format?
 
Show me a photo/screenshot of you iSpindel configuration, please (this is just an example)

1598973970479.png
 
Here is the configuration. At the moment I'm trying to get it to talk to the Grainfather (another problem...) but it will talk to Ubidots when I configure it for that.
 

Attachments

  • Screenshot_20200901-164433.png
    Screenshot_20200901-164433.png
    20.6 KB
  • Screenshot_20200901-164446.png
    Screenshot_20200901-164446.png
    23.2 KB
  • Screenshot_20200901-164500.png
    Screenshot_20200901-164500.png
    23.2 KB
I can't help with Grainfather setup. When you send some Ubidots config shots, I might be able to help you. wink...
 
Good progress on my build today. Everything seems to be working with ubidots, I've got that feeding triggers into IFTTT to turn a warming pad on/off (powered by a smart plug) via webhooks based on high/low temp events. I needed to add a single 5g sugru pack to the base of the cylinder for ballast and to secure the pcb, and then pushed a spare button and screw into that to get 25deg float in water by trial and error (reading 25.2deg in 25C tap water - good enough for me!).
Just need to calibrate in a sugar solution, then try an actual brew!
Most people seem to focus on the gravity readings with ispendel... But I'm most looking forward to being able to monitor and control fermentation temperator through winter in my garage!
I'm planning on putting a guide together on this at some point, in case others are interested.
Do you have the ifttt instructions, and what settings would you use for an ipa?
 
I've taken a few screenshots from the various apps and will aim to get something written up in the next day or two. As for IPA... I'm no brewing expert and I'm sure others will know more about temps... But I'm quite a simple soul and just set my boundaries to 21-23C.
 
iSpindel failing to report data.

This has happened to me twice now, in my previous and current brew. The first time it occurred in mid brew, the second time it happened at the beginning of the brew, before I had even put it in the FV. The fix each time seems to be to go into the configuration and without changing anything, to simply save the configuration and get it to reboot. Rebooting (powering down and back up) alone, does not get it working again.

My present theory as to the cause, is that it relies on the router to give it an IP, once it has been given an IP the iSpindel remembers its IP, not hearing from the iSpindel for a while, a router might decide to reallocate that IP to something else on the LAN, so the iSpindel's data bursts will be ignored, due to the IP clash.

I will admit I have a lot of various items on my local LAN all demanding IP's, many of which use DHCP, requesting to be dynamically allocated an IP by the router. The past few days, I have been trying to sort out my mess of dynamically supplied IP's, to give everything which occasionally connects and needs IP, a static IP address.

I have set all of these IP static allocations in my main router. All that was needed was to know the MAC of each device, the iSpindels MAC number can be found in the configuration. Fill the MAC in the routers form, plus decide on what IP address you want it to have. Likewise everything else which connects to your home LAN - every item will have a unique MAC number of the form ww:xx:yy:zz
 
This is really interesting... I'd be amazed if the ispindel didn't request an ip through dhcp every time it wakes. However, I can see how the developers may just use the same ip to save on battery and assume its still free. Very risky approach though!
It'll also depend on the router. A dhcp lease would usually be valid for several hours after it was last used - maybe if the lease time is very short, the router could reassign it to another mac and therefore cause the clash of the ispindel just reuses the last one. What router are you using, and can you just increase the default lease time?
 

Latest posts

Back
Top