Here you can find the latest firmware. How to install the firmware and image can be found here:

pageDo Firmwareupdate

Version 1.5.6 - 2023-10-16


  • Error in the processing routine.

Version 1.5.5 - 2023-10-14


  • Preparations for Configuration via App By the end of the year, it should be possible to completely set up the Hydrom via the App4Hydrom. Preparations have to be made in the Hydrom for this. If you want to know more, please contact me.

  • Device serial number can now be read out via a JSON file. This is part of the preparation for the app

  • Current FW-Version can now be read out via a JSON file. This is part of the preparation for the app


  • Extend the Client SSID from max. 32 characters to max. 96 characters

  • Extend the Server-Adress from max. 48 characters to max. 96 characters A customer contacted me and asked for the extension because they want to use the AWS cloud service and it specifies the larger addresses.

  • Explanatory texts Calibration For all three types of calibration, explanatory texts have been added to make the distinction easier. One texster had challenges to choose the right calibration method. I am always grateful for such feedback.

  • Explanatory text Bluetooth One texster had challenges to understand that Bluetooth doen´t mean, you can Connect to the Device but to receive the Messages. I am always grateful for such feedback.

  • Renaming Bluetooth UUID in UI There was a query about the meaning behind the UUID. Therefore, the name was changed from UUID to Colour to prevent problems of understanding.

  • Early Feedback Configuration mode enabled. If the Hydrom is not near its WLAn, but you still want to configure the device, it took 15 seconds until the LED lit up green. This led to misunderstandings and multiple presses and subsequently to the assumption that the Hydrom was not reacting. This has been changed. Now the green LED comes on immediately, regardless of whether the WLAn is already ready.

  • Wakeup nach Update


  • Position sensor calibration Fixed a bug that made it necessary to recalibrate the position sensor.

Version 1.5.1 - 2023-07-04


  • More feedback for WLAN There was feedback from a customer asking for more feedback on what was wrong with the Wi-Fi. Additional feedback has been added. You can now see if there is a suitable Wi-Fi in the vicinity.

  • Specific Gravity for Brewblox Now, in addition to the Plato, SG is also transferred to Brewfather.


  • Refactoring Filesystem The file system has been revised.

  • Bluetooth activated after reset.

  • Brewfather pre-selection has been deleted. Unfortunately, the Hint in the instructions did not have the desired effect and many customers still use the discontinued Brewfather interface via "Costum Stream". Therefore it was deleted.


  • Memory Leak. A memory leak was detected, this could under certain circumstances cause the Hydrom to crash and no data to be sent when Bluetooth is switched on.

Version 1.4.4 - 2023-06-02


  • Backwards compatibility Deepsleep activation The option to disable Deepsleep was taken away. This resulted in old versions not having Deepsleep enabled. The bug has been fixed.

Version 1.4.3 - 2023-05-31


  • Feedback clear water calibration. A customer has expressed the wish to receive feedback on whether the calibration was successful. This has been implemented.

  • MPU Calibration via UI. There was an Issue where the position sensor was no longer calibrated. With this function, the calibration can be renewed.


  • Connection attempt duration 20sec. -> 10sec.


  • Tilt Values were not correctly sent via BLE.

  • Fixed some spelling mistakes

  • InfluxDB values are no longer passed as strings.

  • Some security updates

Version 1.4.1 - 2023-03-27


  • Added automatic sending of measured values after power on/deep sleep. There was feedback that it would be useful when the Hydrom is switched on, that then directly a measured value is sent. So you don't have to wait anymore.


  • There is no longer the possibility to turn off the deep sleep.


  • Clear water calibration did not work for a certain batch. This has been fixed.

Version 1.4.0 - 2023-03-23


  • Support for Bierbot Bricks

  • Support for Google Sheets

  • The Hydrom now has an automatic shutdown function when the battery voltage is less than 3 volts, to extend the battery life and ensure the protection of the device.

  • The user interface has been made more resistant. Limited the maximum number of characters.


  • Hydrom name has now been merged with the configuration WLAN name.

  • Bluetooth is now turned on by default.

  • Guided sugar calibration has been deleted. With reference calibration, the hydrom is much more flexible

  • Maximum token size has been increased from 48 characters to 85 characters

  • The maximum password length has been raised from 32 characters to 34 characters

  • Now the Hydrom 15x tries to connect to the WLAN

  • Limitation of decimal places. The measured values that are transmitted are now truncated to a logical size.


  • Some formulations have been changed to German.

  • Some formulations in Dutch have been changed.

  • Telegram: It has been transmitting Plato value so far, even when SG has been discontinued.

Version 1.3.6 - 2023-01-19


  • Telegram: From now on, the device name is sent before the message. This allows multiple devices to be monitored via the same bot.


  • Wifi reconnect: Now the Hydrom tries to connect to the Wifi for 30 seconds. If then no connection was established, then it tries again. As a result, the Hydrom can work reliably even with a poor connection, but the power requirement increases.

Version 1.3.5 - 2023-01-12


  • Warning message when configuration mode is used for too long. There have been some angry customers who used the configuration mode as a productive environment and complained that the battery was empty within 10 hours. This is to prevent this disappointment


  • Typo correction

  • Compensation of an overflow in the framework This has an effect on the calculation of the deepsleep


  • Adjustment of the formula of temperature compensation.

  • Adjustment of the display of the temperature compensation on the main page.

  • Wlan password lengths up to 63 characters can be used now

Version - 2022-12-27


  • There was a bug in the calculation temperature compensation.

Version 1.3.4 - 2022-12-08


  • Upside down detection: The Hydrom stops sending readings when it is upside down. This results in longer battery life and clearer use of readings.

  • Temperature compensation: The Hydrom, like all free-floating hydrometers, is subject to the laws of physics. The measurement result is directly dependent on the temperature. This dependency has now been reduced with the temperature compensation.

  • Telegram Support: With this version the device supports Telegram. By popular request this feature has been added. Sends Plato, temperature (in celsius), battery level (in %) and the transmit power RSSI.

  • For support, "tilt" was added to the json data. should now be supported.


  • Fixed a bug in calculating the time the device should sleep.

  • Fixed URL placeholder values for Specific Density and Battery Percent.


  • for Ubidots Plato is now sent in the "tilt" variable and the raw value of the device's angle is sent in the "angle_RAW" variable

Version 1.3.1 - 2022-8-7


  • The configuration page is now always accessible via Device Wifi. This means that every time you start the configuration mode with the hardware button, the Hydrom sets up its own network. This has many advantages:

    • reliable, even if the existing WLAN is not of good quality.

    • even if the router does not resolve the DNS address correctly, the Hydrom can be accessed

    • you don't need to know the IP of the target device, just enter as described in the instructions.

    • some routers do not allow clients to communicate with each other, so you can still set up the device

    • a guest network can be used to send the data to the internet.

    • if the WiFi data is entered incorrectly, you can still access the device.

  • Direct feedback WiFi setting. You can see directly if the wifi is connected or not. We are still working to find out the cause and output it.

  • There are up to 6 languages for the user interface.

  • Many more explanations have been added to each service.

  • The initial password for the access point has been deleted. Just connect without a password and you're done.

Version 1.2.16 - 2022-4-05


  • Plainwater calibration was repaired.

Version 1.2.15 - 2022-4-03


  • Stabilisation of the position sensor measurements.

  • Ubidots Interface The last update contained an error, which has been eliminated with this update

Version 1.2.14 - 2022-3-30


  • LED on when started in configuration mode The two LEDs are switched on immediately when the unit is started in configuration mode.

  • Wifi reset If the reset button is pressed for longer than 3 seconds, the Hydrom is started with reset Wifi settings.


  • Brewfather Server&Port is now stored persistently. The Brewfather Server address & port has been made changeable.



  • Default Brewblox port changed from 91 to 1883

Version 1.2.13 - 2022-3-11



  • Energy saving: Dynamic WLAN transmission power The Hydrom first tries to send the message with a lower transmission power and then slowly increases it until the message has been sent.

  • Detection: Server reachable (in the service menu) If a test message has been sent, a red or green square is displayed behind the input window for the server address, depending on whether there is a connection or not. To test whether an Internet connection exists, "" can be entered as the server This feature helps to find errors.

  • Detection: Port open on server (in service menu) If a test message has been sent, a red or green square is displayed behind the input window for the port, depending on whether the port is open or not. This feature helps to find errors.


  • Bluetooth transmission power had a spelling mistake


  • Default setting Brewbox Username/Password is now empty.

  • Bluetooth is deactivated by default

  • Higher resolution for battery level calculation

Version 1.2.12 - 2022-2-18


  • Wrong values for Grainfather, Brewfather and Ubidots.\

    Note on Ubidots: The provider only allows a certain number of variables per device. Deleting the variables that are not needed can prevent transmission artefacts.

Version 1.2.11 - 2022-2-10


  • Reading the temperature more stable some customers had experienced unstable temperature values. A mechanism was installed that checks the temperature for plausibility and only accepts it if it is given.

Version 1.2.10 - 2022-1-16



  • Support page was revised

  • InfluxDB name was fixed


  • The default path for Brewfather was adjusted

  • Telegram UI was deleted, because not yet implemented in the backend

  • Thimgsspeak UI was deleted, because not implemented in the backend yet

  • SoftwareReset was deleted, because there were unintended resets. To reset the Hydrom via software, the URI "/reset" must be entered after the IP address.

Version 1.2.9 - 2022-1-10


  • The values for Tilt and Plato have been swapped in the services. This makes the Hydrom compatible with the iSpindle applications.

Version 1.2.8 - 2022-1-5


  • Plainwater calibration is supported

Version 1.2.7 - 2022-1-1


  • Grainfather is supported

Version 1.2.6 - 2021-12-31


  • Fixed error when resetting to factory settings


  • The LEDs no longer flash when the Hydrom is woken up by the timer.

  • All settings are read in before the factory reset, as the offsets of the MPU6050 are not reset.

Version 1.2.5 - 2021-12-30


  • Reset has been stabilised so that a reset is still possible if settings cause the Hydrom to crash too early.


  • It is indicated by LED when you are approaching a "reset". The LEDs flicker in 500ms until the 8 seconds waiting time is reached. Then the flickering ends with a green LED.

Version 1.2.4 - 2021-12-15


  • Some improvements from tester feedback


  • Adjustments to the UI following feedback from testers.

  • Increased the limit of the Plato calculation polynomial from max x^3 to x^6.

Version 1.2.0 - 2021-11-03


  • Deepsleep as long as necessary

  • Firmware upload via web interface

  • Calibration wizard (sugar and reference method)

  • BLE support

  • Wifi (standalone and client mode)

  • Backup/restore settings

  • Ultra low power consumption algorithm

  • Multible cloud services support

    • Brewblox

    • Brewfather

    • Craftbeerpi

    • Fhem

    • Http

    • InfluxDB

    • Mqtt

    • Prometheus

    • Tcontrol

    • Tcp

    • Telegram

    • ThingSpeak

    • Ubidots

  • MPU is calibrated

  • Drift Compansation

  • Support for multiple units for temperature and plato

    • Plato

    • Specific gravity

    • Gravity (position of hydrom in space)

    • Kelvin

    • Fahrenheit

    • Celsius

  • Support of signal LEDs to increase operability.

  • Intuitive web interface

  • Smoothing of measured values

  • Support for a reset button

  • Configurable name to support multiple units in parallel.

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