The iTilt measures gravity of beer during the fermentation process. The iTilt consist of an ESP32 (or ESP8266) microcontroller, MPU6050 Gyroscope, DS18B20 temperature sensor (Optional), battery and battery charger inside a PET preform. The iTilt is inserted into your wort before you add yeast. Initially your brew will have a high gravity (density) because of all the sugar in it. The iTilt may tilt at about 60° (from a vertical line) in your brew. When your brew starts to ferment and sugar is turned into alcohol, the tilt angle will reduce and the iTilt will become more vertical. The gyroscope will continuously monitor this tilt, transform it into gravity (with a statistical model/ polynomial of 3rd degree) and ABV and publish the results to the cloud.
This firmware is compatible with iSpindel hardware.
More info on the iSpindel is available at https://www.ispindel.de/docs/README_en.html and https://github.com/universam1/iSpindel
The standard original iSpindel firmware code was developed in PlatformIO and publishes data to Ubidots, Bierbot Bricks, Blynk etc and few other services. This original source code is complicated (for me) and I wanted something more simplified publishing to Cayenne https://cayenne.mydevices.com/ since I use Cayenne for my other projects. The ESP32 Hardware also provides a better power saving mode (hibernation) compared to the iSpindel ESP8266 DeepSleep. Especially the ESP32-E Firebeetle is ultra-low on power consumption.
https://www.youtube.com/watch?v=O0lS2KwqAwQ&t=261s
| iTilt | iSpindel |
| 1 Publish to Cayenne, Ubidots and Adafruit IO. | 1 Publish to ubidots and other services. |
| 2 Developed in Arduino IDE. | 2 Developed in PlatformIO. |
| 3 Simple for me. | 3 Complicated for me. |
| 4 WiFimanager configuration portal can be loaded while brewing. | 4 WiFimanager configuration portal can’t be loaded while brewing. |
| 5 Polynomial calibration can be done in the WiFiManager Configuration portal with an easy to use wizard. If you use the theoretical gravities suggested in the wizard, you do not even need an extra hydrometer to calibrate. | 5 Calibration done in Excel. |
| 6 Alcohol By Volume is calculated and published to Cayenne, together with Tilt, Current Gravity,Temperature(from the DS18B20 temp sensor or the MPU6050 Gyro internal), Original Gravity, the Coefficients of the Polynomial, battery voltage, battery level % and WiFi Signal Strength. | 6 Data published is Tilt, Gravity, Temperature, Battery Voltage and WiFi Signal Strength. |
| 7 Can run on an ESP32 (Was tested on Wemos lolin 32 and TTGO KOALA) and ESP8266 (Wiring must be according to iSpindel standards). | 7 Only run on ESP8266. |
| 8 ESP32 should consume less power.This need testing. MPU6050 and DS18B20 is powered by GPIO and switch of during hibernation. ESP32 hibernation use less power compaired to ESP8266 deepsleep. | 8 May consume more power. The MPU6050 and DS18B20 is powered from the 3.3v rail and does not switch of during deep sleep |
| 9 One USB C or Micro USB port for charging and programming. | 9 One Micro USB port for programming and one USB C port for charging. |
| 10 Less complicated cuircut. Some ESP32 brands has built in battery circuits and an external charger/battery power supply is not needed. The internal Temperature of the MPU6050 Gyro can be used instead of a DS18B20. | 10 ESP8266 D1 Mini does not have a battery charger/power supply. Extra battery unit required. Need a DS18B20 Temp sensor. |
You will need an iSpindel / iTilt hardware and Cayenne credentials. You need to be skilled in using the Arduino IDE or Loading bin file firmware on an ESP8266. I will not be Liable if you mess up your EPROM or damage anything.
First, test all your hardware on a breadboard.
If your MPU6050 LED does not dim out during deep sleep, you can add a diode between both your sensors and ground. The | mark on the diode must go to GND. (Will not be applicable to ESP32 Firebeetle.)
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My PCB was milled on a CNC. The design was done in Autocad Eagle. The GCODE was generated with PCB gecode setup (Eagle Addon). I also tin plated the pcb
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Create a PCB using CNC or etching.
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Solder the voltage divider. 4.7KOhms resistor between 1 and 2, 10 KOhms resistor between 3 and 4.
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Solder the push button (Reset).
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Solder the DS18B20. Make sure about polarity and use a 4.7KOhms resister between data and 3.3v.
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Solder the MPU6050.
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Solder the ESP32 Firebeetle.
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Reform (narrow) your battery holder with about 5mm to ensure it does not push agains solder joins.
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Attach the battery holder. When you insert the battery, check your polarity.
More Info at https://www.instructables.com/ITilt-Beer-Hydrometer/
RECOMENDED BATTERY: INR 18650 Samsung 30Q (15 amp continues current draw)
To Do: Eagle File PCB
-WiFimanager (Install the latest from Github https://github.com/tzapu/WiFiManager). The arduino library 2.0.3-alpha is out dated and does not support firmware updates.
-ArduinoJson version 6 (Install from Arduino IDE)
-PubSubClient for v1.09 (Install from Arduino IDE) ArduinoMqttClient (Install from Arduino IDE) for iTilt v1.01 to 1.08, CayenneMQTT (Install from Arduino IDE) for v1.00
-OneWire (Install from Arduino IDE)
-DallasTemperature (Install from Arduino IDE)
-MPU6050 (Install from Arduino IDE)
-curveFitting (Install from the Arduino IDE)
-Load the Firmware from source or binary on your iSpindel. If you had the iSpindel firmware (or other firmware using SPIFFS) installed, you may need format your SPIFFS. Read the disclaimer.
-The LED_BUILTIN (Blue LED in my case) should flash
-Place your iTilt horizontal or vertical on a levelled surface. Reset it. You will see a few flashes of the Builtin LED. The green LED of the Gyro should be on.
-You will now see that the iTilt created an Access point.
-Connect to the AP. Go to http://192.168.4.1 if it is not automaticly loaded.
-Provide all the required details in Configure Wifi. You will need your Cayenne cridentials and a calibrated polynomial if already done (The statistical model to transform tilt into gravity. See https://www.ispindel.de/docs/README_en.html). Always re select your Internet WiFi AP and retype your password in the configuration page, otherwise no parameters will be saved.
-If you still need to calibrate your polynomial, make the portal time out 9000 and publication interval 0. Publication interval =0 means deep sleep is avoided and data is published to Cayenne +- every 20 seconds.
-Do not enter your Original Gravity yet (Except if you measured it with another hydrometer or got it from your recipe).
-Save the provided details.
-Reset your WiFimanager configuration portal by shorting the reset pins and tilt the decice vertical.
-Log into your iTilt AP again.
-Make sure all details saved is correct in WiFi Configure WiFi.
-You can now do an offset calibration. Remember to place your iSpindel vertical. You should manualy insert the offset (with its sign) in the Configure WiFi page.
-Save the offset (remember to re select your internet access point and password)
-Reconect to the Configuration Portal. Do a polynomial calibration by following the wizard. It is recomended to do easy calibration with 7 ordered pairs (sample size=7) of (tilt, gravity). You will need a jar (+/- 3L), clean water and 0.55 kg sugar. Manualy enter the coefficients in the Configure WiFi page. SAVE. Reconect to Conf Portal (iSpindel_Cayenne).
-You can now enter your Original Gravity (if the iTilt is in the brew) from the Gravity reading 192.168.4.1/readings? . Provide your WiFi password again and save your new details.
-Also change the WiFi Manager portal Time Out to about 300 seconds and the Data Publication Interval to 900 seconds (about 15 minutes).
-Your iTilt should start to publish to Cayenne.
-Short the Reset pin while holding the iTilt vertical or
-Hold the device in a vertical or horizontal position.
-While Brewing: Draw the iSpindel vertical against the plastic fermenter with a strong magnet. Keep it like that. The iSpindel will detect it is vertical when it wakes out of deep sleep. This may take time, dependent on your selected publication interval.
Gyro LED is Blue or Red.
ESP32 Firebeetle LED is green. ESP32 Firebeetle charge indicater is red. If of, charge is finish.
Gyro LED on and ESP LED ON, Awaike from deep sleep. All sensors will be readed.
Gyro LED of and ESP LED still on, Connecting to WiFi and send data to cloud.
Gyro and ESP LED of, ESP8266 is in deep sleep / ESP32 in hibernation.
10 Short flashes of ESP LED, WiFiManager Configuration portal will start in three minutes.
- VERTICAL OR HORIZONTAL WITH BATTERY DOWN
On reset, Configuration portal will run
- HORIZONTAL, BATTERY SIDEWAYS
On reset, the iTilt will enter hibernation mode. This is the ideal mode to store device or charge the battery.
poly_calibration.mp4
-You will need ordered pairs of Measured tilt readings and Gravity readings. Follow the wizard that use a sugar wash calculater to make sure your gravity readings is correct.
-The best polynomial is a 3rd degree of the form GRAVITY=Coefficient3 x Tilt^3+Coefficient2 x Tilt^2+Coefficient1 x Tilt+ConstantTerm (^2 means to the power of 2)
-While calculating your polynomial, you can set the Publication Interval to 0. This will ensure that the ESP8266 (ESP32) does not enter deep sleep and publish data about every 20 seconds to cayenne.
-You can also get Tilt Readings from the senor reading page 192.168.4.1/readings? Make sure your portal time out(set in Configure WiFi) is long enought (9000 seconds) to finish calibration.
-If you struggle with the Maths and the wizard, use the following Coefficients Coefficient3=0.000001000000000 Coefficient2=-0.000131373000000 Coefficient1=0.006967952000000 ConstantTerm=0.892383559880001
-Rule of Thumb: If The Polynomial estimates gravity to high, reduce the Coefficient1 a little bit
-If you already have a 2nd degree polynomial, you can use it and just make the coefficient of tilt^3 = 0.
My results in Excel using the Data Analysis tool pack. You can see that the results calculated by the Polynomial Calibration Wizard corresponds with excel. You can also see that the Polynomial is closed to a perfect fit with a Coefficient of determination (R^2)=0.9998
Channel 0: iTilt ID Number
Channel 1: Battery Capacity percentage
Channel 2: Gyro Internal Temp.
Channel 3: The Firmware Version. Can not display on the Dashboard, See it in the Data Stream.
Channel 4: Temperature in D Celcius
Channel 5: Tilt
Channel 6: Battery Voltage
Channel 7: Gravity
Channel 8: Publication Interval in seconds
Channel 9: Original Gravity
Channel 10: ABV
Channel 11: Signal Strength
v1.01
1 Replace the CayenneMQTT library with ArduinoMqttClient. This new library avoids the long loop in CayenneMQTT. The average time it takes to connect to WiFi, publish data and go to deep sleep is now less than 5 seconds.
2 Optimize code, WiFiManager custom params is only created if the portal will run
3 The Polynomial Calibration Wizard is improved. Instructions to use results from sugar wash calculaters is included.
4 The cayenne chanels was updated.
v1.02
1 Improve Power management of the DS18B20 and MPU6050. They are only switched on for about a second to take proper readings.
2 Provide estimate of remaining battery capacity based on voltage: Source:http://www.benzoenergy.com/blog/post/what-is-the-relationship-between-voltage-and-capacity-of-18650-li-ion-battery.html
v1.0.3
New web page for Custom Pin configurations. If you can not use the default pin configurations for Power, SDA, SCL and ONE WIRE.
v1.04
1 Cosmetic Improvements for HTML
2 Faster sensor readings using sample size arguments and reducing duplicate function calls to calcTilt().
3 WiFiManager Configuration Portal: Password is now the mac adsress.
v1.05 Certain GPIOS does not go LOW during deep sleep. Use the following to resolve: #include "esp_sleep.h"
gpio_hold_en (GPIO_NUM_33);
gpio_deep_sleep_hold_en();
gpio_hold_dis (GPIO_NUM_33);
v1.06 Read both DS18B20 and internal Temp of MPU6050. The MPU6050 Temp sensor has a resolution of 1 deg Celsius. It Configuration mode the MPU 6050 will head up and readings can be +-2 degrees to high. When the iTilt is publishing to the cloud it should not heat up since the iTilt is in deep sleep most of the time. On Saturday 5 March 2022 I managed to get the first iTilt hardware to work properly. It used an ESP32-E Firebeetle and Firmware 1.06.
v1.07 New Function calcRoll. Display the roll in Sensor Readings Page. Longer delay (based on wifi signal strength) to make sure data is publish to cayenne.
v1.08 Move cayenne things to function pubToCayenne(). Hibernate (Switch off) if roll <20 or roll>160. Hibernate if Battery Voltage is less than 3.00 volt. This function is located in setup(), so it will not be called if the voltage get under 3 volt while in Configuration Portal.
v1.09 Replace the ArduinomqttClient library with PubSubClient Library. This Library has better reviews and ArduinomqttClient could not publish to Ubidots for some reason.
Ubidots and AdafruitIO cloud options added.
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Add aditional cloud services (Dash Boards), publish to beer apps. Publish to multiple services simultaneously.
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Provide options to send data via BLE
Considerations:
1 Get a board that will fit in the PET Tube.
2 Boards must also be low on power consumption during operation and deep sleep.
3 Board must have a strong WiFi signal. The sparkfun thing failed this criteria. The antena must be located near the lid of the PET tube.
The ESP32-E DF Robot looks like the best current board.
The TTGO Koala looks like a contestant at this stage since its battery connection is next to the USB port and the charger is braked out to the PINS. It seems like it runs low on battery during operation and deep sleep. I tested it in a coffee urn (1mm thick stainless steel) and WiFi signal was low, but still worked. The battery charger only charge up to 4.08 volt (80%).
The Wemos Lolin32 was tested on a breadboard. The GPIO could not power the MPU6050 and DS18B20 and you will have to power them via the 3.3 volt pin. You may use a transistor to switch them on and off to save power. You will also have to remove the battery connector to fit into your PET tube. Some soldering will be needed to make the battery unit working again.
The Sparkfun ESP32 Thing was tested. None of my two boards WiFi worked correctly. You may have better luck with them.
Other options may be the DF Robot Fire beetle.
Do not load this firmware if you do not know what you are doing. This firmware over write what is on the iSpindel. It formats a File System (Called SPIFFS) on your EEPROM. If want to revert back to the iSpindel software, you need format your SPIFFS. by loading https://github.com/JJSlabbert/iTilt/blob/main/format_esp_fact_defaults.ino.ino.d1_mini.bin or running https://github.com/JJSlabbert/iTilt/blob/main/format_esp_fact_defaults.ino
I do not take any responsibility for any damage caused.
You are free to use this binary or source code (software) for non-commercial objectives, like home brewing for private use.
You may not include this software in a product that you cell or produce for commercial objectives.
You may not use this software for producing any commercial product that you sell.
If you want to use this software commercially, you need to get permission from the copyright owner.
Commercial Licenses will be available at a reasonable price.
Copy right holder: Jacobus Johannes Slabbert
1 MPU6050 LED BLINKING ON AND OFF
Check the solder joints. The battery holder may push against solder joints and effect the contact.
2 ESP32 HEATING WHEN IN DEEP SLEEP, BATTERY LOOSING POWER, BATTERY CHARGE NEVER COMPLETES.
Inspect solder joints for bridges. Inspect the resistors (voltage devider) between the pcb and ESP32.
3 While Fermenting, the gravity and tilt is to low (ABV is to high) or iTilt stop working
This may be caused by a leaking PET preform. Remove the iTilt from your beer, clean the electronics with isopropyl alcohol (99%) and let it dry.
The tilt (comercial hydro meter) has a Patent in the USA. I am not awaire of any similiar patent in any other country. The USA Patent may apply if you are staying in the USA. Fortunate in may country, we have proper patent right laws. You will not be able to register a micro controler, battery management system and gyro as a patent. All boat, airplaine companies and courts will laught at such a patent.