Automated IoT Propagator

Introduction: Automated IoT Propagator

Seedlings are often needed to start a garden, especially if you live in areas where summer season lasts just a few months. Usually no one has a luxury of many window sills and even if they do, it is all too dependent on sunny days. Automated propagator with climate control not only helps to sprout seeds faster, do it in a controlled manner, but saves space too. Herbs, vegetables, flowers - all of the seeds can be started in such propagator! Disclaimer: this project mostly concentrates on how to automate propagator not how to build one from scratch, but if you need more details on any aspect of this project, let me know!

Needed software:

1. Arduino IDE

2. Blynk (mobile app)


1. Propagator

2. Seedling trays, planters

3. Reflecting material - aluminum foil or similar

4. Wemos D1 R1

5. 4 way 5V relay

6. Humidity&temperature sensor DHT11

7. FC-28 soil moisture sensor

8. DC12V 3W micro water pump with DC connector

9. DC12 V fan

10. DC12V heat mat

11. 12V DC power supply (~5A, depends on how powerful pump, fan and heat mat is)

9. 12V DC 5m of 6400K 25W/m (1700Lm) and 5m of blue 3, 6 W/m LED strips

10. 150W 12V power supply.

11. Wires, silicone tubing

Step 1: Wiring

Connect wires as shown in the picture:

1) DHT11 signal pin to D2;

2) FC-28 sensor signal pin to A0;

3) Connect relay pins In1-In4 to D3-D6 respectively;

4) Connect LED positive lane through relay 1, pump - relay 2, fan - relay 3, heat mat - relay 4.

GND pins to GND, Vcc to 5V.

Step 2: Code

Download file below (open in with an Arduino IDE), upload sketch to a Wemos D1 R1 board. DO not forget to add ssid and password of your network.

Step 3: Blynk Setup

Propagator automation setup has two modes: auto and manual. When selected Auto, LEDs are controlled according to timer parameters, pump work is dependent on moisture sensor readings, fan and heat mat control depends on humidity&temperature sensor readings. When selected Manual, pick one of the devices from the drop menu and use ON/OFF buttons to set wanted environmental conditions.

1. If you do not have Blynk App, download it (check out how to do it here).

2. Start a new project, you'll receive Auth Token. Add it to the Arduino code.

3. From widget box select:

Segmented switch;


2x Button;

Time input;


RTC(real-time clock);


Check out pictures to set up parameters of each widget.

Step 4: Tips

1. Wrap copper wire around both "legs" of moisture sensor, solder it. Original electrodes oxidize fast and once it does, it stops working. With additional wire it can work longer and once it is oxidized, it can be changed.

2. Heat mat can be made of car seat heater.

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