iSpindle - DIY Electronic Hydrometer

Pulled some wort to measure the gravity by hydrometer.
The reading is exact what iSpindel reports. After applying temperature calibration, it is 1 point off.
It's not perfect but good enough for me. I would like to share some tips of calibration:

1.The nature of accelerometer is noisy. The reading won't be steady, even if you fixed it on solid ground. However, unlike gyro, the reading won't drift too far. Therefore, be patient. Take some readings, say 10, and use the median value.

2. Make sure the iSpindel floats freely without touching anything.

3. [Edited] Try to run the calibration at the same temperature, say 68F/20C. I think temperature correction to hydrometer is not necessary. The working principle of iSpindel is the same as hydrometer. The higher gravity, the more they float. When the temperature drops, the "gravity" rises. The real gravity rises because the volume of water shrinks.
When we brewers talk about "gravity", we usually means the gravity calibration at 68F or 59F, because the amount of sugar is what we want to specify. Don't mess up them.
If your are using refractometer, make sure you use correct correction factor. I think you don't need to apply the correction if you are using sugar dilution method.


4. Make sure the sled or anything doesn't move after calibration.

 

Mine is flashed with 4.16 and powered by battery. I have the diode soldered in with the cathode at D0. I had it this way and it didn't work so I reversed it, of course that didn't fix it. I have turned it back around now. I have just gone back and reconfigured it to start again from scratch. It is reporting figures that are expected in the test page (temp, angle and voltage). I'll double check solder joints I guess as it only seems to be a wake up problem.

 

Working now. Maybe I just needed to go to the config page again and reset.

Now for some 3D printing.

 

Ok i find it there is no way to flash it if it is on usb charge!!!only with battery!! Lets see the config now!! Has anyone add wireless charge reciever??

 

Yeah this is what I meant when I said you have to have the battery connected. There's is not enough power from the USB through the lipo.

 

I spent ages getting the parts, building, configuring, calibrating etc etc, a lot of messing around but finally got it working, I was feeling pretty pleased.

Now it's inside my ss brewtech chronical fermenter it can't get a wifi signal, not even to the wemos d1 mini that's running brewpiless only 1m away. Frustrated.

Once I've bottled the current brew will experiment to see if there's anything I can do about the signal, maybe some silicon tube around the clips to electrically isolate the lid from the body (avoid Faraday cage). Anyone else had similar problems?

 

Someone earlier in the thread attached and external antenna, that might offer a bit more power

 

Thanks, I'll look that up. I did specifically get a d1 mini pro so I could attach an external antenna if necessary, turning the resistor looks tricky though.

 

I highly recommend adding an external antenna as the worth and fridge door blocks the signal too much. Look up my earlier post for some links and pics

The resistor is a bit tricky yes..

 

I got some of the parts ordered yesterday, and am working on gathering up the odds and ends. One question I have (ok, one of a few, but the only one I'm asking this morning)...

What is up with the reed switch? I've seen it mentioned here and there, but I don't see it in most schematics. Was it an alternative to the main switch?

 

Yes it is, I used a little slide switch which seems to work fine, it's in the AliExpress wish list I shared and is pretty cheap

 

Thanks! Hopefully I can get the rest of the components ordered today. I'm going to try to make an Adafruit Huzzah variant of it.

 

Dear All,

I know a few of us have had some trouble with the iSpindel going into deep sleep and not waking at the prescribed time (say every 15min).
I built several boards with 470 ohms resistors that failed to wake, and only when I used a BAT43 Schottky diode did it work. However, my question is has anyone had any success using a lower resistor of say 390, 350 or 330 ohms?
The reason for this, is I believe that a Schottky diode will still cut out when the battery voltage to say 3.6 volts in comparison to a resistor of the correct value may go down to 2.8 volts.
Therefore, any input would be appreciated?
Thanks.

 

If you go back to page 4 of this thread I link the pelting I got from ebay.

Word of warning though it doesn't seem to fit the sleds that you can download from the iSpindel GitHub but the one I bought from 3d-mechatronics.de did fit perfectly.

 

Thanks, got everything on order! I have a 3d printer so will have to modify the sled models to fit a bit better. Thanks for the help.

 

I've been reading through this, but I wanted to skip to the end and reap the rewards without reading all 35 pages or so. It looks like it works, so I want one. My question is, since I'm a novice at soldering boards and processor programming, can I do this? What would it cost to have one made for me (that wouldn't be fun, but just checking my options).

If I go to the github and download the .zip file, will it have a program that I would be able to install on the processor?

Sorry, I know it's wrong of me to come in without reading everything, but I've grown so accustom to instant gratification with the internet, I don't want to wait.

 

I've been reading through this, but I wanted to skip to the end and reap the rewards without reading all 35 pages or so. It looks like it works, so I want one. My question is, since I'm a novice at soldering boards and processor programming, can I do this? What would it cost to have one made for me (that wouldn't be fun, but just checking my options).

If I go to the github and download the .zip file, will it have a program that I would be able to install on the processor?

Sorry, I know it's wrong of me to come in without reading everything, but I've grown so accustom to instant gratification with the internet, I don't want to wait.

I guess my question is "other than the board that can be ordered for $7, is the list on the github page still the best components to get? Is there an updated component listing?

18650 LiIo cell (e.g., Panasonic NCR18650B)


///Components
•Wemos D1 mini
•GY-521 Gyro & Acceleration Sensor (MPU-6050 on suitable breakout board)
•DS18B20 Temperature Sensor
•Square grid 3x4cm or printed circuit board
•Resistors - 4k7 ohms - 220k ohms - 470 ohms
•microswitches Or at the PCB Reed Wechsler
•Lipo charger TP4056 (6 pin recommended)

http://cachers-world.de/de/Petling-XL

 

Yes you can do it, my soldering level is amateur at best and I managed to solder the bits together to get it to work. Hardest bit for me was cutting the breadboard to size.

The board I put together makes it's a fair bit easier.

You can get everything you need from the German site I listed earlier and that's about €50 you still need to solder and assemble though.

 

How much have the sleds tended to cost to print? The online 3D printing vendors I've found seem to range in the $14-$17 range. I've never 3D printed anything, so I don't know if that is par for the course or not.

 

Check your local library. I think I paid less than $5.00 for mine.
http://www.austinlibrary.org/site/PageServer?pagename=Spring_2014_News_NewCentral

 

To both you, that PCB looks super!
Would be perfect in a bit larger and longer version where gryo then is placed just as mine in the cap-head of a yeast tube! Gonna look at Kicad and see if I can make one version just a bit larger and hold 4 copper lines for placing the gyro downwards!

Any chance to get the orginal files?

 

Thank you, @mikmonken did all the heavy lifting. Let me know if I can help you.

 

Use a 330 ohm resistor instead of 470 ohm.

 

On the D1 Mini Pro, where is the diode to remove?

Cheers.

 

Unfortunately our local branch is still "planning on getting one" sometime in 2017, and the main branch is supposed to have one when it reopens (it is already after the original reopening date). I haven't checked the other neighborhood branches though.

I did just come across this site though: https://www.3dhubs.com. It seems to connect you with local businesses or people with 3D printers. The lower end for the sled seems to be around $5-7.

 

I used 3D hubs to print a couple of sleds and it was AUD$14 for two of them. The guy did a great job but I still had to take to them with a file to get them in the tube. This was for a custom designed sled which, with the benefit of hindsight, has been customised further. I'm currently using a variant of this one https://www.thingiverse.com/thing:2225597

 

Another question, how to calibrate ispindel in order to show the SG and not the Plato ?

which type is the correct in column Abweichung °
= IF( [@[gemessener °Plato]] <> ""; [@[gemessener °Plato]] - ( 0,008699786 * [@[gemessener Winkel (°)]] * [@[gemessener Winkel (°)]] - 0,457563239 * [@[gemessener Winkel (°)]] + 5,15023517 );"")

Which is the correct type for Plato Formel row?
0.008699786*tilt^2 - 0.457563239*tilt + 5.15023517

 

Good to hear that you had a positive experience with 3D Hubs. I'll be printing a custom sled as well because I'm using the Adafruit Feather Huzzah, and had to do some fancy positioning with the boards to get everything to fit. The components should be here next week, but unfortunately the pelting is a few more weeks out.

 

Should be this one. I believe it has the letters SL written on it

 

Well, 3D hubs is all down to the individual with the printer. I had a few to choose from but ended up with the one closest to work so I could pick up easily. Turned out fine.

I'd be interested to see your sled. My mods were due to a different charging module.

 

Here it is: https://tinkercad.com/things/gQz4HZnh6by

It is still rough, once the components all come in I'll get more precise measurements. It is based on no math whatsoever, I just hope it tilts close to the right angle. The Huzzah will slide into the inner slot, and the MPU-6050 and perfboard into the outer one. The battery holder has feet that will clip into the holes, and hopefully the little "wings" with keep it stable against the pelting wall.

Parts List

• Adafruit Feather HUZZAH
• DFRobot MPU-6050
• Generic Perfboard for resistors and such
• DS18S20 Temp Sensor
• NC Reed Switch
• Magnet for reed switch
• Battery clip for 18650
• Battery

 

i follow the calibration method 2 in 0 Plato (1000 SG) tilt shows 73,34 an on 12,4 plato (1050 SG) tilt shows 80,14 is that correct?

 

Thank you.

 

I'm considering using 3D Hubs as well, but I'm not sure what material to select for the printed part.

Here are the choices:

1. FDM
2. SLA
3. SLS

Anyone able to offer some advice?

Thanks!

 

I won't say it's "incorrect", but it is suggested to make it around 15~25 tilt in water.
I bet you need to put some weight, usually around 15g to 25g, at the bottom.

 

I would like to know which is best as well?

Thanks.

 

With i have 10 grams shows 14,47 on plato 0 i think that is good!!

 

Good for you.

IMO, if it tilts around 70~80 at 1.080, that would be perfect.

 

i will try to calibrate it with 1.080 solution today lets see.....

 

Woo hoo. I have a live ispindle. Thanks guys for your posts. Very helpful. I had some issues with the spindle accepting changes in the config screen so I changed the 470 ohm resistor to the shottky and it now accepts the changes. You wouldn't believe it but my internet connection is now down so I can't get back to ubibots. So close!