iSpindel communication problem and solution

Homebrew Talk

Help Support Homebrew Talk:

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

sdbbp

Supporting Member
HBT Supporter
Joined
Aug 3, 2023
Messages
47
Reaction score
33
Location
Oakland, CA, USA
This was my third fermentation with an iSpindel I built from kit.

The first fermentation went well. I had done a multi-point calibration, but just focused on relative SG movements to gauge when FG was reached. Not all updates from the device made it to my WiFi network, due to distances and enclosure in a fridge. But enough did to make it useful. I'll eventually get a WiFi access point closer to see if that helps. I used a free ubidots account to collect data.

For the second fermentation, I switched to Brewfather. I confirmed connection, then dropped the iSpindel into the vessel. Oops. Apparently Brewfather needs the device name to include "[SG]" to indicate that it is transmitting SG vs Plato and there's no option to toggle that in Brewfather. So that was a bust (no SG/tilt info) and I had to use from-spigot refractometer measurements to check progress.

For the third fermentation, I remembered to change the device name and confirmed data samples were being recorded correctly. So I pitched the packet of dry yeast and dropped in the iSpindel. That maybe wasn't the best idea, as I saw the dry yeast coat the iSpindel as it went in. I received early readings, but within about 10 hours, the readings stopped. The next day, with the krausen, I wasn't able to visually inspect the device to see if it was flooded or such, so I just let it go. On day five I visited and decided to tip/swirl the vessel to knock down some of the krausen gunk and perhaps "rouse" the yeast to keep going. I saw the iSpindel was still floating, so at least it wasn't completely inundated. Later that night, I got a reading, then more overnight. So it looks like too much stuff stuck to the iSpindel significantly affects the signal. Some suggest to drop in the iSpindel after high krausen, but I'm concerned about the oxygen exposure, but if it's still in the middle of fermentation, perhaps it's not harmful.

In this case, swirling/sloshing the FV helped to bring back the iSpindel signal.
 
Hi
What kind of design did you build?

Krausen doesn't effect the transmission at all, it will effect the readings a bit, but not the trend.

Not sure if brewfather tells you the wifi signal strength that the ispindel is measuring, high 80s to low 90s is bad.

Distance from your router / access point reduces signal, SSteel fridges also don't help and certainly SS fermenters.

Given that you built an ispindel you should easily be able to make one of these.

https://github.com/martin-ger/esp_wifi_repeater

I use this and they work great, I added a secondary antenna which makes a huge difference using these instructions

https://www.instructables.com/External-Antenna-for-ESP8266/

I extracted the antenna from an old router that I picked up at a junk shop / trash recycler.

There is a very long thread on this forum about the ispindel.

https://www.homebrewtalk.com/threads/ispindle-diy-electronic-hydrometer.598187/


This thread using a really well supported software change and added features is worth exploring, I've migrated to this software.

https://www.homebrewtalk.com/threads/replacement-firmware-for-ispindel-gravitymon.698058/

This lot should see you right.
 
Thanks, I didn't find the long-running thread yesterday, else I would have posted in there. I'm not sure exactly why, but readings came back after I swirled the FV (Fermonster). Before and after the "blackout", I am getting about 1 reading per hour (out of the every-fifteen-minute frequency). It's in a normal non-SS fridge, but I know the wifi attenuation is bad. I'll eventually get a WAP closer.

I do plan to try the GravityMon FW, as it supports multiple destinations. So I can get full telemetry to someplace like ubidots along with the Brewfather integration.
 
Any metal fridg will act as a Faraday jail and almost block the wifi signal.
There are a cheap trick with a “pasive repeater “. That is 2 antennas conected back to back, one inside and the other ouside the fridge.
 
I just have the repeater with the aerial on about 4 foot away from the fridge.
My fridge is stainless steel but plastic fermenter.
You haven't mentioned the design of ispindel that you made?
 
It's this kit [https://www.ebay.com/itm/294746798927]. CherryPhilip iSpindel PCB 4.0 with a D1 mini. Recent stock FW.
That kit is fine, the early ispindels that I started with were made with the d1 mini, gyro and charger modules stacked on a small motherboard like a multilayer sandwich.
This had a fundamental problem in that the design had the wifi antenna below the liquid surface. My signal was really poor with this design.
 
Problem one was the ispindel was set up for the weaker of the two SSIDs. Oops.

So I set it up for the better one, which also has the repeater now in the room.

ispindel outside the fridge: RSSI -61
ispindel inside the fridge: RSSI -68

I *think* that -61 indicates that it's not actually connected via the repeater. I'll have to put it back in configuration mode and check through the MAC or something. That might be problem two, since earlier I reported

> Outside the chamber, the source WAP is -58dB and the repeater is at -39dB, reported by my phone.

I'm also planning to try GravityMon. So I'll flash to that, then play around some more. I'll get this set up as well as I can *before* dropping it in the next batch for a two week tour.
 
-61 is better signal than -68 but both are pretty good.

I used to get missed info from the ispindel when it was -80 or bigger.
 
After fun getting GravityMon up and running, I'm now at -61 inside the fridge and seemingly getting all or most updates. It's nice to be able to log to both ubidots and brewfather, with the correct units, and without mangling the device name (using the GravityMon feature to use Plato just for the brewfather endpoint). I think I'm ready for another brew day.
 
Back
Top