The STEMinds Eduponics Mini is a smart-agriculture and IoT board. With an ESP32 module at its heart, Eduponics Mini features an array of built-in sensors—including temperature, humidity, barometric, ambient light, water quantity, and soil moisture sensors—that work together to make smart agriculture easy and affordable. It supports Wi-Fi and Bluetooth connectivity and consumes very little power, making it perfect for real-world IoT applications.
We believe that high-quality industrial-IoT and smart-agriculture technology should be accessible to everyone, not just to those with significant resources and technical expertise. Using MicroPython or Arduino IDE, you can design your smart garden in no time. We’ve assembled all of the documentation you will need to guide you, step-by-step, into the world of electronics and programming.
Eduponics Mini can help you develop essential Industry-4.0 skills while creating real-world applications that are also useful in your daily life. Examples might include:
- An automated plant-watering system
- Environmental monitoring and data-driven irrigation projects
- Hydroponics and aquaponics (using external sensors)
- An IoT weather station
- A smart aquarium- or reef-monitoring system
- Research to inform plant-growth and disease predictions
User-Customizable Mobile App
We’ve designed and developed an easy-to-use mobile app for the Eduponics system. It has a React Native user interface and a public MQTT broker on the backend, which means there’s no need to deploy and maintain a database. It allows you to:
- Control and monitor an unlimited number of plants
- Water and monitor your plants remotely, from anywhere
- Monitor soil moisture, humidity, temperature, and sunlight exposure
The Eduponics App currently supports soil-moisture sensors only, but we are working to add support for hydroponics and even smart-aquarium projects!
In addition, we’ve created a library to help you modify nearly every aspect of the app. With it, you can add plants, rename them, configure new sensors, and more. It is currently available for Android and will soon will be available for iOS.
Versatile, Industrial-Quality Hardware
From the beginning, quality has been our highest priority for Eduponics Mini, and we’ve worked hard to integrate the best possible sensor components on the market. Our Soil Moisture Sensors are suitable for long-term, real-life applications and will continue operating—hassle free—without supervision.
100% Compatible With Hydroponics and Aquaponics
In Hydroponics we often need to use multiple submersible sensors to measure pH, EC, TDS, ORP, and other such indicators. Doing so can be challenging, however, because those sensors are typically unable to operate at the same time without interfering with one another. While working on Eduponics Mini, we researched a few DIY solutions using relays to turn the sensors on and off…but then we came with a solution that is both easier and more effective!
Using the Eduponics Mini Extension board, you can toggle the analog sensor state, which allows multiple sensors to operate simultaneously without conflict. And no current will flow when we’re not using the sensors, which results in lower power consumption.
And the best part? This entire process is fully automated in our library and requires no additional code!
Who Are We?
We started developing Eduponics in response to the massive food shortages we observed in the early days of the COVID-19 pandemic. We were looking for quick, efficient, at-home techniques for growing our own veggies and greens.
After looking into a few high-quality DIY water-irrigation systems—including the necessary control boards, modules, and sensors—we almost gave up due to the high cost (and the even higher level-of-effort) required to use the existing solutions we identified. Instead, we decided to step up and make a difference by designing our own smart-agriculture and IoT development kit. And so Eduponics Mini was born.
Available Products
Eduponics Mini Kit
- Eduponics Mini Board
- One STEMinds soil-moisture sensor (short)
- Contact-less water quantity sensor and two-sided attachment sticker
- Screwdriver for adjusting the potentiometer on the water-quantity sensor
- 12 V submersible water pump
- 12 V / 2 A DC power supply
- USB Type-C data cable
- Water hose for the pump
- Water regulator to regulate the flow
Eduponics Mini
Click to expand
- Integrated ESP32-WROVER module with built-in Wi-Fi and Bluetooth support and an external antenna connector
- Support 5-12 V power input via DC and USB Type-C interfaces
- Compatible with Arduino IDE and MicroPython
- XH2.54 2P Interface for pump, integrated with built-in relay
- XH2.54 3P Interface for soil-moisture sensor (or any other analog or digital device)
- XH2.54 4P Interface for water-quantity sensor
- On/Off and Reset switches and a "wake-up" button to resume from deep-sleep mode
- Integrated I²C RTC DS1307 module (coin-cell battery not included)
- Integrated I²C BH1750 I²C light sensor
- Integrated I²C BME280 temperature, humidity and barometric sensor (3 in 1)
- Integrated I²C AT24C02 EEPROM
- Extension pins for DHT11 / DHT22 sensors (DHT sensor not included)
- IO Extension pins to connect extra sensors with 3.3 - 12 V output pins
- Dimensions: 53 x 71 mm
STEMinds Soil Moisture sensors
- Corrosion-resistant, Capacitive soil-moisture sensor
- 5 V operating voltage, 3.3 V output (voltage regulator is built-in)
- Highly accurate and precise
- Short Sensor dimensions: 20 x 102.03 mm
- Long Sensor dimensions: 20 x 155.03 mm
Eduponics Mini Extension board
We are working hard to enhance the core Eduponics-Mini functionality. We’ve already developed a custom extension board that includes an extremely accurate ADS1115 ADC and the MCP23017 IO extension IC. The Eduponics Mini Extension Board comes with an extra four relays and an extra four analog inputs that connect directly to the ADS1115 ADC.
In the near future, we will be making additional extensions with sensors that monitor things like pH, EC and water temperature.
Click to expand
- ADS1115 ADC chipset for precise analog data reading
- MCP23017 IO chipset, connected directly to four relays and capable of activating and deactivating ADC sensors
- External interrupt pins on data change for MCP23017
- External interrupt alert on analog data changes for ADS1115
- Four Relay modules with XH2.54 connectors and 5-24 V support
- I²C interface (only two pins required)
- I²C addresses changeable by changing resistors
- Compatible with Arduino, Raspberry Pi, ESP32, and other controllers
- Dimensions: 53 x 71 mm
Comparisons
Eduponics Mini offers far more functionality than similar projects in the same price range. It is also far more extensible. With dozen of external I/O pins, Eduponics Mini allows you to integrate any sensor you wish.
Smart Agriculture Kits
| Eduponics Mini | EcoDuino | Watering kit | Smart Plant Care | Gardening Add-On Kit | |
|---|---|---|---|---|---|
| Manufacturer | STEMinds | DFRobot | Elecrow | Seeed Studio | STEMpedia |
| MCU | ESP32 | ATmega | ATmega | None | None |
| Kit Price | $69.00 | $53.90 | $59.00 | $59.90 | $54.00 |
| Soil Moisture sensor | Yes (custom design) | Yes | Yes | Yes | Yes (Corrosive) |
| Extension IO pins | Yes | No | No | Yes | No |
| Wi-Fi | Yes | No | No | No | No |
| Bluetooth/BLE | Yes | No | No | No | HC05 Bluetooth module |
| Environmental sensors | BME280 | DHT11 | No | DHT11 | No |
| Low powered | Supports deep sleep | No | No | No | No |
| Protection enclosure | STL files provided | Yes | No | No | No |
| RTC Module | Yes | No | Yes | No | No |
| Ambient light sensor | Yes | No | No | Yes | Yes |
| Water quantity sensor | Yes | No | No | No | No |
| IoT Mobile app | Yes, Eduponics APP | No | No | No | No |
| Indications | RGB LED | No | OLED Display | OLED Display | Blue/Red LEDs |
| EEPROM | Yes | No | No | No | No |
| Battery / solar powered | External module | External module | No | No | No |
| Open Source | Schematic+SW+STL | SW | SW | HW+SW | SW |
| Programming languages | Arduino, MicroPython | Arduino C | Arduino C | Arduino C | Arduino C |
| USB interface | Type-C | Micro-USB | Micro-USB | None | None |
| Supported extensions | Yes | No | No | Arduino HATs or Grove | No |
| Documentation | Complete, Arduino+Python | Minimal | Minimal | Minimal | Minimal |
While looking for soil-moisture sensors to use with our kit, we found ourselves struggling. The sensors we were finding just weren’t good enough! We purchased and tested multiple sensors and eventually decided to make our own. As you can see in the comparison below, our sensor has the highest voltage range and sensitivity between all the sensors we’ve tested, allowing you to create a stable and precise high resolution smart agriculture and IoT applications.
Soil-Moisture Sensors
| STEMinds (Short) | STEMinds (Long) | DFRobot | Grove Seeed studio | Generic v1.2 | |
|---|---|---|---|---|---|
| Type of sensor | Capacitive | Capacitive | Capacitive | Capacitive | Capacitive |
| Operating voltage | 5 V | 5 V | 3.3 - 5.5 V | 3.3 - 5 V | 3.3 - 5 V |
| Min voltage output | 0.987 V | 0.561 V | 2.468 V | 2.378 V | 1.022 V |
| Max voltage output | 3.3 V | 3.3 V | 3.112 V | 3.570 V | 2.300 V |
| Min output value | 154 g | 106 | 260 | 494 | 214 |
| Max output value | 668 | 683 | 517 | 745 | 480 |
| Operation current | 7 mA | 7 mA | 5 mA | 8 mA | 6 mA |
| Resolution (high-low) | 514 | 577 | 257 | 251 | 266 |
| Sensor price | $4 | $5 | $5.90 | $5.90 | $1.6 |
Please note the following:
- Soil-moisture test results are for educational reference only. Different environments might produce different results
- We purchased original sensors from authorized distributors where possible
- Generic v 1.2 refers to sensors, produced in China, without a manufacturer or a brand. (Some Chinese companies sell these sensors under their own brands.)
- All sensors were tested with an Arduino Uno using the analog pins and 5 V as input
- Maximum voltage and output refer to values when the sensor is in open air
- Minimum voltage and output refer to values when the sensor is submerged under water
- Operation current measured using a Fluke multimeter
Support & Documentation
We’ve created over 15 detailed lessons to help you get started with Eduponics Mini. You can find these tutorials, which are available for both Arduino IDE and MicroPython, on our wiki. We plan to open source the wiki soon (on GitHub) so that anyone with modifications or clarifications can contribute. We also plan to create step-by-step video tutorials on programming the sensors and using the IDE. Subscribe to our campaign updates to learn more as we release these tutorials!
Our code is completely open source (under the MIT license) and available for anyone to modify change, distribute or use. While Eduponics Mini supports both MicroPython and Arduino IDE, MicroPython is currently given higher priority. This might change in the future and we hope to support more programming languages and environments to meet the needs of our backers.
