Automated Hydroponics Prototype

An automated hydroponic farming system integrated with IoT, enabling efficient, soil-free cultivation of leafy greens/herbs in compact, limited-space environments.

Misc. Items

1. 1x Food-grade reservoir/grow tray (3D-printed)
2. Rubber pipes (for plumbing connections)
3. Plant pots (for plant support and growth medium)
4. Net cups (550 mm top diameter, 500 mm height)
5. Sponge seed starters (60 mm diameter, 30 mm depth)
6. Mini lettuce seeds
7. Hydroponic nutrients (A and B solutions)

Lighting System

1. LED grow light panel (200 x 200 mm, 36W)

ensors & Monitoring

1. 1x pH sensor kit with probe (E201-C BNC)
2. 1x EC sensor kit with probe (DJS-1)
3. 1x water temperature sensor (DS18B20)
4. 2x water level sensor (reservoir: MSP20; grow tray: XU5-1)

Pumps & Aeration

1. 1x submersible water pump (DC2.5-5.5V, 120mA, JT-DC3W-3)
2. 1x adjustable USB oxygen pump with 2cm air stones (DC4.5V, 0.35A)
3. 4x peristaltic pumps (DC7.4V, 0.4A) – nutrient A, nutrient B, pH down
4. 1x electronic valve (DC9V, 200mA) – controls freshwater inlet from faucet based on reservoir water-level
5. 1x cooling fan (DC5V, 200mA)
6. 1x water heater

Automation & Control

1. 1x Arduino UNO R4 WiFi microcontroller
2. R4 shield attachment (if not wanting to use the breadboard)
3. Power supply (cable or batteries)
4. Breadboard and jumper wires (for electrical connections)
5. Timer (optional: controls photoperiod)

1. Print the reservoir and grow-tray STL files (scale the model by a factor of 2 and use ≥ 20 % infill).
2. Clean supports and seal internal surfaces if needed.
3. Dry-fit all 3D-printed parts before inserting sensors or tubing.

Reservoir (bottom) – mount water pump, EC & pH sensors, temperature probe, and MSP20 level sensor.

Grow tray (mid) – insert XU5-1 level sensor and air stone; route overflow drain back to reservoir.

Lighting rack (top) – attach the LED panel and the cooling fan.

Connect tubing for nutrient flow and fresh-water inlet (valve-controlled).

Check seals and prevent water near electronics

Mount the Arduino UNO R4 WiFi inside a waterproof box.

Wire sensors and actuators to separate analog/digital pins as in the Pin Assignment table (page 78).

Keep 5 V and 12 V lines isolated; use common GND.

Add LED indicators (Green = Stable, Yellow = Adjusting, Red = Critical).

Open Hydroponics_Dashboard_may13a.ino in Arduino IDE.

Install required libraries (ArduinoIoTCloud, WiFiS3, DallasTemperature, Adafruit_AMG88xx, etc.).

Edit arduino_secrets.h with your Wi-Fi SSID + password.

Upload the sketch and confirm sensor readings in Serial Monitor.

Calibrate each sensor using the procedure tables (pH buffers 4.00 / 6.86 / 9.18, EC buffers 1413 µS and 12.88 mS).

Create a new Thing and import variables for pH, EC, temp, water levels, and status LEDs.

Link dashboard widgets (gauges, charts, switches).

Test real-time updates and alerts via email or phone notifications.

Target ranges

1. pH ≈ 5.8 EC ≈ 1.6 mS/cm
2. Water depth (grow tray) = 3 – 5 cm
3. Temp ≈ 18 °C

Logic flow

1. If pH ↑ → dose “pH down.”
2. If EC ↓ → run Nutrient A/B pumps.
3. If the reservoir is low → open the fresh-water valve.
4. If tray dry → alert + stop lights.

Target ranges

1. pH ≈ 5.8 EC ≈ 1.6 mS/cm
2. Water depth (grow tray) = 3 – 5 cm
3. Temp ≈ 18 °C

Logic flow

1. If pH ↑ → dose “pH down.”
2. If EC ↓ → run Nutrient A/B pumps.
3. If the reservoir is low → open the fresh-water valve.
4. If tray dry → alert + stop lights.
5. If thermal hotspots > −0.5 Laplacian → start fan.

Fill reservoir with nutrient solution and power on.

Observe green LED (stable). Change conditions to trigger yellow/red LEDs.

Verify each automation:

1. pH sensor → peristaltic pump runs
2. Water low → valve opens
3. Overheat → fan starts

Confirm live updates on IoT dashboard and alert emails

Place seedlings in net cups with sponge starters.

Let automation run 24 h; monitor graphs and alerts.

Refill nutrients weekly and log growth rate, pH, and EC.

Evaluate performance against your success metrics (yield, stability, water efficiency).

Common issues

1. False water-level alerts → recalibrate sensors after install.
2. Overheating under LEDs → adjust fan angle or distance.
3. pH drift → clean probe tips and replace buffer weekly.

Future enhancements

1. Automated thermal map generation
2. Timed lighting schedule via RTC
3. Nutrient database for different plant species
4. Improved grow-tray drain ports planned after field demo