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The iSpindel DIY Hydrometer

The iSpindel DIY Hydrometer

This month (November, 2021) David McCarthy gave us a talk about the iSpindel DIY hydrometer covering how you can buy or build one and how they work.

London Amateur Brewers

November 15, 2021
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Transcript

  1. David McCarthy
    iSpindel
    An Introduction

    View Slide

  2. Subjects discussed
    • iSpindel and other Digital Hydrometers
    • Roots of the technology - Birth of the Maker movement
    • iSpindel Components – Buy or Build
    • Operation and Config
    • Connectivity options
    • Does it make better beer?

    View Slide

  3. iSpindel – What is it?
    • A digital hydrometer and thermometer
    • Uses commonly available components
    connected together
    • Simple construction
    • Cheap
    • Internet of things - Communicates using Wifi
    to web services
    • Open source – Free source code, can be
    reused, distributed or modified
    • As such, it is a community development

    View Slide

  4. Digital Hydrometers
    Tilt iSpindel Float
    Cost Size (mm) Comms Support BrewFather
    Tilt £139 92 x Ø28.6 Bluetooth a a
    iSpindel ~£25-£35 120 x Ø40 Wifi r a
    Float £139.97 160 x Ø40 Wifi a a
    • iSpindel is far cheaper
    • Benefits from its size
    • It isn’t commercial, you’re on your own
    • No graphing/website/app provided
    • Lots of community users
    • eBay sellers are fairly responsive

    View Slide

  5. iSpindel – Roots
    • The Tilt already existed – from a kickstarter campaign in 2014
    • Fortunately, a couple of those guys were brewers, and saw an
    opportunity to build their own
    • Came out of the Arduino / Raspberry Pi open source movement
    • Microcontroller uses a programmable IDE
    • Arduino software and coding
    • Projects encouraged – home controllers, monitoring solutions,
    robots, IoT solutions, drones.

    View Slide

  6. iSpindel - Components
    WEMOS
    - Wifi
    - I/O Ports
    - CPU &
    Code
    Thermometer
    3-Axis
    Acceleration
    Gyroscope
    Battery
    Charger
    USB
    Data is fed from the two sensors to
    the WEMOS unit for processing

    View Slide

  7. iSpindel – wired up
    On/Off
    Data from accelerometer
    to WEMOS
    Data from
    thermometer to
    WEMOS
    Charging Unit
    WEMOS micro controller

    View Slide

  8. • As at today on eBay
    iSpindel – Buy or Build?
    • All the parts laid out

    View Slide

  9. • YouTube Channel Woolly Craft Beer
    has some great videos on building the
    iSpindel, calibrating it, and then
    linking to BrewFather
    • Open Source distilling also has a
    collection of videos on all these
    topics, and he has even developed his
    own PCB
    I have created a web page to collate
    links and resources for future reference
    Building an iSpindel

    View Slide

  10. iSpindel – Basic Operation
    Configures a wireless Access point
    So you can then see the device in your home WiFi
    networks (see right)
    Uses some important information to set up the
    device. So you need to connect to it and enter these
    values
    The basic operation is that it sleeps, and then every
    seconds, it wakes up, and sends the sensor
    values to a via your , with
    an to translate the angle into a gravity

    View Slide

  11. iSpindel – Baseline config
    Home W ifi SSID
    1
    1
    2
    3
    4
    4
    The iSpindel Home Screen
    Screen 1 shows you the values on
    the device at the moment
    Screen 4 gives you a load of
    information about the device, the
    code version, memory usage etc.
    Screen 3 is Calibration, coming
    next.
    Screen 2 we will cover last, as it
    shows how we tell the iSpindel
    how to operate.

    View Slide

  12. iSpindel - Calibration
    Offset Calibration - device on the horizontal Calibrate in water
    Place in water
    Check the angle
    Should be 25 degrees +/- 5 deg.
    If too high, push board into tube
    If still too high, fix washers to the
    bottom
    (I’ve used BluTack!)
    3

    View Slide

  13. iSpindel – Gravity Calibration
    After Offset Calibration - device on the horizontal
    And water calibration – adjust to 25 degree angle
    Go to
    https://www.ispindel.de/tools/calibration/calibra
    tion.htm
    Make successive solutions of syrup (sugar and
    water) from 1.080 to 1.000 in 0.010 steps
    Enter the values in the boxes at the top, click add
    data each time
    The polynomial calculates at the bottom:

    View Slide

  14. iSpindel Configuration
    Home W ifi SSID
    1
    2
    2
    2
    3
    4
    Available
    Wifi
    Networks
    Home Wifi that iSpindel will use
    Home Wifi password
    How you want the device to ID itself
    900 seconds = every 15mins, the
    device will wake itself up
    Name of the Web Service
    Access Token
    Polynomial to convert angle to
    gravity

    View Slide

  15. iSpindel Options - Connectivity

    View Slide

  16. iSpindel - Ubidots
    Enter the Ubidots token provided on
    the web site
    The device automatically appears in
    Ubidots

    View Slide

  17. iSpindel - Brewfather
    The URL comes from Brewfather itself
    The iSpindel name must have [SG] added to
    report Specific Gravity, not Plato

    View Slide

  18. BrewPi

    View Slide

  19. BrewPi → BrewPiLess

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  20. A graph in more detail
    Slowishstart for 2 to 3
    hours before the cliff
    drop
    Reaches terminal gravity
    almost exactly 3.5 days in
    Quite a jagged line
    Temperature range
    broadly within 1.5
    degrees
    Slope changes
    measurably 4-6 points
    before terminal gravity Terminal gravity lower in
    value than expected FG

    View Slide

  21. Does it make better beer? (1)
    It is helpful to see what’s going on in the fermentation
    • My first couple of batches had higher FGs, so I had “Noob Nerves”
    • Seeing the fermentation progress helps confirm that things are on track
    • Measuring the temperature of the wort in the FV may be different to the external temperature of
    the vessel
    It’s helpful not to have to take samples from the wort
    • If you don’t have a tap/spigot, then you’re removing the lid, risk of oxidation
    • If you’re a small batch brewer, then you resent giving it away just to know
    • Although you should always confirm the FG with a hydrometer once you are satisfied it is done
    • A godsend if you’re pressure fermenting
    Having the graphs is a visual record of what happened
    • With the same setup, you can see how a particular yeast perfoms for you
    • I can compare the attenuation curves of multiple yeasts,
    • You can more accurately assess the lag time (effect of a vitality starter, or rehydrating dry yeast)

    View Slide

  22. Does it make better beer? (2)
    Dry hopping
    • whether at high kreusen or as the fermentation is finishing, you can track that on the graph
    Using the fermentation process to carbonate the beer
    • Judging when you are 4 points away from finishing could be challenging, but you can get ball
    park
    Knowing when to package from the FV
    • 3 days of stable SG tell you it’s done. You can package and condition however you want
    thereafter.
    • If you’re on a schedule, you have the data to see how things are progressing
    Modifying the fermentation temperature profile
    • Timing a diacetyl rest is made easier
    • The precise values of the SG are affected by what’s happening in the FV
    • Kreusen, CO2, yeast matter all affect the angle
    • I have found that my FGs are lower than the target FG in a recipe
    • But the trends are shown faithfully, and the slope of the curve is hugely insightful

    View Slide

  23. Does it make better beer? (3)
    Hop Creep
    • Dry hopping liberates fermentable sugars
    • Enzyme activity varies across cultivars
    Stuck Fermentation
    • It wont fix it, but you’ll know when you’ve got one,
    and you can track the recovery steps thereafter
    • e.g. raising the temperature a couple of degrees or
    adding a little fresh yeast may encourage the yeast to
    process another couple of gravity points, and you’ll be
    able to see that, as an alternative to daily hydrometer
    checks

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  24. November 2021
    Thanks All!

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  25. Hobbyist Microcontrollers
    • NodeMCU, started in 2015
    as an IoT board, with an
    ESP8266 processor
    • Raspberry Pi 2012, single board
    computer
    • Arduino – 2005 as a
    teaching aid –
    microcontroller, can
    be programmed
    from a PC

    View Slide

  26. Why has this caught on?
    • They are accessible to beginners/kids
    • Because they are cheap, reliable, low
    power
    • You can connect devices or sensors to
    the pins
    • Because you can make them perform
    quite complex functions with some
    basic code, all written on your PC
    • There is a huge user base, and code
    base too
    • Manufacturers started seeing the
    benefits of using them
    Arduino Leonardo Raspberry Pi4 Model B WeMos D1 Mini
    £15 £33 £2.88
    5-7V (100-200mA) 5V (2A) 3.3V (~70mA)
    20g 46g 3g
    68 x 53 85mm x 56mm 34mm x 25mm
    Arduino IDE Python, Scratch Arduino IDE

    View Slide