This guide was made for indoor gardeners, would like to build an Arduino grow tent automation with a browser-based user interface, logging to Google Sheets, and email alerts. We also discuss building an LED light, setting up irrigation, installing a carbon filter, and preparing the grow medium. The information presented here was gathered from forums, articles, and videos, combined with personal experience and feedback from the grower community. Hope to hear from you too!
Embedded Files
Main module: Houses the Arduino Mega and ESP8266 chips, AC relays, temperature, humidity and light sensors, dimming circuit, and the LED driver. Collects sensor readings from the other modules wirelessly and reports them to Google Sheets.
Reservoir module: Measures the reservoir weight, pH, water temperature, air temperature, and humidity.
Aeroponics module: Measures the pressure and controls the high-pressure pump, bypass solenoid, and spray solenoids.
Hempy module: Measures the weight of the Hempy buckets and waste reservoirs. Controls watering based on the measured weight. (Photo outdated)
Home Assistant Dashboard
Main module
Arduino Mega2560, AC input, Dual LED drivers with PWM dimming, Dual speed Internal/Exhaust fan AC outputs, 12V DC power brick to power all modules. Placed outside the grow box, communicates wirelessly with other modulesMain module
Main module extension
Temperature, humidity, and light sensors are connected to the main module via a UTP cable. Placed inside the grow box.Main module extension
Reservoir module
Arduino Nano RF, 12V DC power input, Sensors: Water temperature, pH, Reservoir weight, Air temp/humidityReservoir module
Hempy module
Arduino Nano RF, 12V DC power input, Weight sensor + pump controller for two Hempy bucketsHempy module
Aeroponics module
Arduino Nano RF, 12V DC power input, pressure sensor, and relays to control the high-pressure pump, bypass solenoid, and spray solenoidAeroponics module
The Gbox420 Arduino sketch monitors and controls the grow tent. It also provides a web interface and reports sensor readings to Google Sheets.
The sketch runs on an Arduino Mega2560 microcontroller and connects to the internet over an ESP8266 WiFi microchip running the ESP-link firmware.
The ESP-link firmware has a built-in web-server that hosts the control interface for the grow tent. This is available on the local WiFi from a mobile, tablet, or desktop PC. (VPN tunnel option in progress)
The sensor readings are relayed to Google Sheets and processed using Google App Scripts to generate historical charts, trigger email alerts and compile a summary page of the current status of the grow tent. This is available online using a browser or the Google Sheets mobile app.
Serial output relayed to the web interface
There is no need to connect a USB cable to monitor the Arduino's serial output, it is relayed to the grow box control websiteSerial output relayed to the web interface
Email alert sample
When a new alert triggers or an existing alert is resolved a summary email is triggered. Several charts are attached to the email for a quick overviewEmail alert sample
Home assistant integration
Home assistant integration
Grafana dashboard
Grafana dashboard
Node-RED dashboard
Node-RED dashboard
Hempy buckets
Hempy buckets
Hempy bucket: A non-transparent bucket with a hole in its side. It functions as a passive hydroponic setup by retaining water at the bottom 5 cm / 2 inch section. We are essentially tricking our plant into thinking it found a natural water pocket at the bottom of the bucket.
Grow medium: The bottom layer is pure perlite filled until it covers the drain hole completely. The rest is filled with coconut coir soil and perlite mix (4 to 1 ratio)
Hempy module: Arduino Nano-based, monitors the weight of the buckets to determine when and how long to water the plants. Controls the dedicated irrigation pumps.
Irrigation: Consists of a large barrel storing the nutrient solution, and for each bucket: a waste reservoir, 4-way water slitter, 4 drip spikes, and dedicated self-priming diaphragm pump.
Weight table: Pine frame + four 50kg/110lbs weight platforms. With waterproof lacquer finish.
Table frame + Waste platforms
Table frame + Waste platforms
Hempy module + pumps
Hempy module + pumps
Aeroponics is a form of growing plants without soil. Roots are suspended mid-air and periodically sprayed with a nutrient solution mist which is generated by a high-pressure pump.
The aeroponics module controls the pump and the two valves for the spray circuit and monitors the pH, spray pressure, water level, and temperature. It reports readings to the Main module wirelessly.
The bottom of the tote doubles as a reservoir. Any debris, plant material that could block the misting heads or damage the pressure pump are removed from the high-pressure circuit using metal mesh filters.
For maintenance, a ball tap valve allows the draining of the reservoir.
Intake/output filters and bypass solenoid
Metal mesh filters are protecting the misting heads and the high-pressure pump, the bypass valve helps with air removal and pressure releaseIntake/output filters and bypass solenoid
Misting loop in action
Loop made from compression fittings and HDPE tubes, the high-pressure pump Misting loop in action
creates 6.5 bar / 95 psi pressure with 12 misting heads
The grow lights are made using high-efficiency LED strips and a power-efficient constant current LED driver.
The lightweight aluminum frame is made from L profile aluminum and functions as a cooling surface along with providing physical support to the LED strips.
The LED strips can handle currents from 700 mA to 1400mA. Depending on the number of strips and LED driver selection the total wattage can vary from 180W to 480W based on your preference.
The color temperature of the light is geared towards the red spectrum (3500K) for flowering, with two extra blue spectrum (5000K) strips added for vegetative growth.
Fresh air enters the grow tent at the bottom through light and dust-proof intakes.
The air is circulated inside the box by an internal fan, mounted on the top.
Air is extracted at the top through a carbon filter to remove odors and channeled outside with flexible tubing.
Internal fan
14" Twin speed internal fan, Arduino controlledInternal fan
Exhaust fan
5” Twin speed inline fan with carbon filter, Arduino controlledExhaust fan
Setup summary
Setup summary
Light 1: 14 LED strips, 1568 LEDs total - 480W , 1400mA (Flowering - 3500K color temp)
Light 2: 8 x LED strips, 896 LEDs total - 180W, 700mA (Seedling / Vegetative - 5000K color temp)
5” / 125mm x 300mm carbon filter, 500 m3/h
5” twin speed inline fan, 220/360 m3/h
High pressure aeroponics tote (Up to 2 plants)
Two Hempy buckets
Why did I write this guide
Why did I write this guide
This is my way of celebrating that as of October 17, 2018, Canada legalized recreational use and home cultivation of cannabis. Canadian residents are allowed to grow four plants up to a height of 100 cm in their homes. I believe many people would like to give home growing a try and I would like to provide them a starting point with this guide. I know that the chances are low, but my goal is to collect enough money to move to Canada to become a farmer. Learning more about indoor and outdoor cultivation, publishing grow journals, improving the current setup, and building new ones sounds like a dream job to me. Thank you for checking out my project, if you like it please consider becoming my Patron 😊
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