Introduction: Pot2

About: Please support and share our mission; the Plant Doctor is a non-profit, open source online research laboratory specializing in electronics+plants. Our vision is to bring together nature and technology in a s...

hello world,

pot2 is an open source smart pot. it can alarm you on the phone/tablet and by changing colors when thirsty, cold, sleeping etc. please support our mission;igg.me/at/smartplants

our goal is to bring together nature & technology in a simple, non harmful way. costs as low as $20 and a weekend to build - same technology in pot2 can be implemented in a greenhouse or smart home automation project - now with blynk app and 3D printable body.!!

- open source hardware + software

- solder-free, non toxic

- suitable for any age group, plug&play

pot2 is an all around educational tool. once completed the end user will know how to build circuits, program and end up with a finished device that can teach them how to garden. no prior electronics or gardening experience needed.!!

here is a list of what we will be using;

1x wifi nodemcu board (arduino)

1x usb rechargable battery pack

1x breadboard

1x RGB led

1x temperature & humidity sensor

1x light sensor

1x water sensor

16x jumper wires

4x magnets


-- project kits available --


let's build..>

Step 1: Design

our first step is to 3D print pot2 - you can reach the design files on www.thingiverse.com/thing:1781292

included are ready to print STL and sketchup files.

it is designed to be able to print without any support to speed up the print process, at fast print should take about 8-10hrs

Step 2: Updates

the older design was for CNC and laser cutters. realizing these machines are not easily available to the public, we updated the plant pot with a 3D printable frame.


more than double the soil capacity compared to the old model. also more room in the electronics compartment


edge lit smartLED alarm system gives it a more natural feeling.


pot2 is equipped with nodemcu wifi board. a much stronger computer with better and easier to program wifi capability.


blynk phone app ready, now you can easily keep an eye on (and control) your garden from anywhere in the world.!!


**this is an update to the plant pot research project - world's first stand alone smart plant pot

Step 3: Circuit

using the jumper cables and the breadboard, slowly connect the circuit together.


double check all connections BEFORE powering up the board.!!

Step 4: Temperature & Humidity Sensor

pot2 can be equipped with both dht11 and the newer model dht22 digital temperature & humidity sensor. temperature is displayed in C and humidity in %.

DHT11 is 20-80% humidity readings with 5% accuracy and 0-50°C temperature readings ±2°C accuracy.

DHT22 is 0-100% humidity readings with 2-5% accuracy and -40 to 80°C temperature readings ±0.5°C accuracy


place it with the back side down as shown in the picture, revealing the connection pins upwards. bend the pins one at a time to desired angle if necessary.

Step 5: Light Sensor

the tiny solar panel looking part of the light sensor sits flush with the door cover. it has to be able to pick up the light levels, so make sure it's not covered by the cover or wall & other obstacles in the room


light sensor is digital, it only sends 0 or 1 as data. the sensitivity can be adjusted using the tiny little blue screw on the sensor - without the need to reprogram arduino.

Step 6: Water Sensor

water sensor is analog and can read data from 0-1023 and alarm you when this value is between 0-300 - you will see this value in the code, it can be adjusted for different plants.


it goes through the body and into the soil. when the soil dries out, the number mentioned above drops due to low conductivity.

Step 7: Edge Lit Notification System

this is a very exciting update. the light are now much more visible and stylish compared to the older model.


for this step you will need 40 x 116mm wide clear acrylic at 0.25" thickness. you can also 3D print this part as well using clean filament.!! this piece sits nicely on the ceiling of the electronics compartment.


using hot glue secure the neopixel smartLED in the middle of the plastic bar. the clear plastic will nicely carry the light across the side.

Step 8: Blynk Setup

we'll first start with getting the blynk app ready on phone/tablet.

zoom here; https://www.instructables.com/files/orig/FAO/ALW9/I...


- download blynk app on device

- start new project, name it, choose board: esp8266, email yourself AUTH TOKEN

- add widget > value display m > name: water, input V4 0-1023 > read freq: 11sec

- add widget > value display m > name: light, input V3 0-1 > read freq: 11sec

- add widget > value display m > name: temp c, input V1 0-45 > read freq: push

- add widget > value display m > name: humid %, input V2 0-100 > read freq: push

- add widget > button > name: blue led, output GP2, mode: switch //onboard led 1

- add widget > button > name: red led, output GP16, mode: switch //onboard led 2

- add widget > history graph > data to show: V1, V2, V3, V4

- add widget > email

Step 9: Arduino Code

to program pot2 we must first follow few one time only quick download/install steps. ask in comments if you are stuck.

- install the little computer's driver on laptop

- install arduino software on laptop

- install neopixel library

- install adafruit unified sensor driver

- install blynk library to arduino software

- get arduino software ready for the little computer

- restart computer before going any further.!!


here is the code,
make sure to carefully read lines 1-26 and make necessary changes in your code before upload.!!

you must copy & paste the code above to the arduino software on your computer.

- open arduino software

- clear the text in the box, and paste the code from above

- plug in pot2 to laptop

- go to files > tools > boards > scroll down to choose "nodemcu 1.0"

- go to files > tools > port > scroll down to choose the correct port associated with nodemcu board

- after changing the wifi & blynk credentials in the code, now go to sketch > upload. after it compiles for errors, upload will begin and pot2 will be online shortly after

NOTE***use this code instead for analog RGB LED; http://bit.ly/2KYuONT

Step 10: Gardening

it's time to get dirty - fill up your pot with soil.!!


bury some seeds at the top; www.instructables.com/3-Days-from-Seed-to-Sprouting-Plants

or transplant a grown plant; www.instructables.com/id/re-pot-a-Plant/


welcome to the wonderful world of plants :)

Step 11: Conclusion

we hope this instructable will help get your project started, and maybe it will interest you into electronics, programming or even gardening.!! remember to ask for help in the comments. for other gardening instruments, check out; www.instructables.com/id/the-Plant-Doctor-family


thank you for your interest. please follow, favorite & share




    • Fix It! Contest

      Fix It! Contest
    • Water Contest

      Water Contest
    • Creative Misuse Contest

      Creative Misuse Contest

    41 Discussions

    My name is Akin Yildiz. I am an inventor/entrepreneur. Just over two years ago I started an online plants & electronics research project, the Plant Doctor - Plant Care Instruments.


    I have recently launched a small scale crowdfunding campaign to bring more awareness to the overall project. We offer DIY kits that teach you how to program, build circuits and garden.

    love & peace


    it comes with blynk library, when you install blynk it should have it all..

    simpletimer.h no longer exist in blynk

    In last version in download exist only:





    So, how to solve the problem???

    Hi Akin , nice proyect , one question about code structure why you do

    void temp_humid()

    void water_light()

    void setup()

    And then only two lines in the loop ?

    Also , this lines are working ?

    timer.setInterval(5000, water_light);

    timer.setInterval(1000, temp_humid);

    Is the pot reading 3 times a day with this lines ?

    Thank you very much Akin .

    1 reply

    so sad i just saw this, instructables does not notify me anymore consistently :(
    two lines in loop because i believe blynk runs smoother that way. just create functions as mentioned above and call them with timer. and yes the timersetinterval lines do work, the code and hardware works, i use it daily. no it takes a reading every 5-10 seconds i believe, which is unnecessary, it should only take 1-3 readings/day and save battery..
    hope this helps, you can mail me smartplantpot@gmail.com

    No such file or directory

    I found the file on my computer. Why is it not working. The file BlynkSimpleEsp8266.h is on my computer. NEED HELP!

    1 reply

    sounds like you extracted the library to a wrong location. where is the file located.? it needs to be in C:/program files/arduino/libraries, extracted in libraries folder. check this out, it may help; https://www.arduino.cc/en/Guide/Libraries#toc4 -
    sorry for the late response, instructables never emailed me about this comment :(

    Do I have to put a 10K resistor between the Vcc pin and the Digital Out Pin on the temperature sensor (DHT11) ? Because I did all test I can and I'm beginning to think my DHT11 isnt working at all.

    1 reply

    do you have the same exact DHT11 i am using in the post above.? if so no you do not need a resistor. if you are using a DHT11 sensor without plug and play module, as is, then yes you do need a resistor. can you share a picture of your dht11 sensor please.?! sorry for the long response, instructables never emailed me about this comment :(

    I don't understand the quick download steps. I clicked every step and downloaded it and I cannot find the board in the Arduino software. Please Help!

    1 reply

    You could have made is a little more easy!

    How do you include all of the files???

    Is Not WORKING

    So many ERRORS!


    1 year ago

    I've bought the 25$ Plant Doctor Gift Pack on Indiegogo with water soil sensor and rgb led included. But I just can't get the RGB-led to work.

    The sensor is working just fine and with blynk and also the buttons to switch off the light on the arduino board work just fine.

    Am i missing something?

    4 replies

    hmm, the code above should make the LED turn blue when thirsty.. and green otherwise
    did you install the adafruit neopixel library.? i highly doubt the led is broken, we are overseeing something.
    im sure you've checked the wiring on the light to be sure :)
    on the back of the light, did i solder it to the correct pin, wires from arduino should go into Din, 3V (or Vin) and GND..
    in the code, lines 74 and 80 tells it to turn blue and red. (0, 0, 0, 250) means, 0 led - 1st one, i want 0 red, 0 green but 250 blue - full brightness
    can you please take 3 clear pictures from different angles on your wiring and post here so i can see.. im glad you got the sensor and wifi working with blynk, that part is much harder :)

    2 pictures og the wiring of NeoPixel. I also have the NeoPixel library installed.


    weird, everything looks good. let's do a neopixel only test. open arduino software, go to files > examples > arduino neopixel > simple - a new screen with the example code will open up. change the lines;

    #define PIN 6 to #define PIN 14

    #define NUMPIXELS 16 to #define NUMPIXELS 1

    upload. after upload the LED should turn green. do this and let me know.!

    Well, still nothing :-(

    Maybe the neopixel is dead or something