In 2016, a brewers' community materialized an open-source electronic hydrometer that allows anyone in the world to improve their fermentation processes by capturing valuable real-time data

The so-called "iSpindel" measures specific gravity and temperature. These key variables allow us to capture the changes in the floating device inclination angle against the device's buoyancy. The captured data is related to the sugar content of the fermenting liquid which allows us to measure the fermentation process efficiently without having to take daily manual proves.

The goal of this guide is to explain how to replicate the iSpindel, and how to transmit its data to Ubidots STEM, learning how to monitor and control the beer fermentation process efficiently.

To replicate the iSpindel, you must have the following parts/components:

NOTE: You can also buy this prepackaged iSpindel kit which includes all the pieces you need to build your own hydrometer.

1. Establish the connection of the components as shown in the following diagram. For more detailed information about the wiring, we highly recommend checking out this documentation.

2. Upload the latest version of the iSpindel's firmware in the Wemos D1 mini.

IMPORTANT: To ensure optimal functionality with Ubidots STEM, please make sure to use the firmware version v6.2.0.

3. Now it’s time to assemble the different parts and components until you get something like this:

To make sure all steps are covered correctly, you should refer to the official repository which explains how to mount all pieces together in detail, including the components' proper wiring.

Once everything works properly, insert them all into the plastic cylinder. At this point, you should have the following result:
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To build your own hydrometer, it's best to reach out to people in the iSpindel community. Once you have your own hydrometer to work with, it’s time to start monitoring your data with Ubidots STEM.

1. Turn on the iSpindel by flipping the switch to the left. Once the device turns on, the Wemos D1 mini will blink a few times.

2. Press the Wemos D1 mini's reset button to generate an Access Point (AP). This is where all device configurations are applied, such as WiFi credentials and Ubidots token.

3. Check out the available networks on your device and establish a connection with the network called "iSpindel":
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4. Once the connection is established, you'll be redirected to the following web page for configuration:

NOTE: If you're not redirected to the page above, open a web browser and enter the following IP address to access it: http://192.168.4.1/.

5. To verify correct iSpindel functionality, select the "iSpindel Info" tab. In this section, you should see the different variables updating their respective values. Check that the firmware version displayed on screen is the latest currently available (or at least 6.1.1).
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6. Select the "Configuration" tab and fill out the fields shown below. Keep the default values for all other fields:

After filling out all the fields required, you should have something like this:
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To save the changes, press the “Save” button.

7. Go to your Ubidots STEM account, enter the Device section (Devices > Devices), and note how the iSpindel configuration was automatically created in your Ubidots’ account.

To see dynamic variable data, click on the device that you created:

If you want to add the measuring unit to a specific variable, you can do it by following this guide: Add Units of Measure.

To present and gather insights from the devices' data, we suggest exploring Ubidots Dashboards. Here you can create widgets to display your data in charts, indicators, controls, tables, graphs, and more.

To create a dashboard, go to the Dashboard tab (Data →  Dashboards). Then, select the plus (+) icon in the top-right corner, select the desired widget type, and set the configuration required. At the end, you should have something like this:

Ubidots supports integrated events that allow you to send Events, Alerts, and Notifications based on your sensors’ data. To learn more about events, check out this guide:

 Check out the type of events supported and learn how to set up each of them

The iSpindel concept is helping home-brewers all over the world in taking care of their fermenting process. With this little device, you can monitor crucial fermentation variables efficiently without spending hundreds of dollars in additional gear.

In case you haven't brewed beer yet, this is your chance to do both:

1) Build your own DIY electronic hydrometer

2) Brew your first round of beers to test the hydrometer

Happy brewing! 🍻

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