Greenhouse automation project

I bought some books for my son on Arduino and Raspberry pi a while back and at the time I wasn't very interested in it. Then I decided I was going to try to buy something that would send me data on temperature/ humidity on each green house. Also to check if all my fans are cutting on and off. I'm not sure how I would do that either a wind sensor of some type or a rpm sensor to put directly in front the fan. Would this be possible with on or both. Could it be done with an Arduino board or a combination of both.

I still have much to learn, but luckily for me i'm capable!

Thanks in Advance!


I would go for an RPM type sensor. Maybe a hall-effect or "prox sensor" (proximity, specifically proximity of iron metal.)

I have also seen some simple flapper type things in the airflow with prox switches on them for airflow - but the hall effect would work the same - caution - the flapper might need to be fine tuned if you have natural airflow with the fan off and also depends on the orientation of the fan (horizontal/vertical etc.)

Then if the greenhouses are a ways apart some sort of communication link or wires to get the signals to your central unit/display - - radio would be an option also - might need more than one processor - but small processors are not very expensive

many places - Sparkfun & Adafruit sell Temp/humidity sensors that are in a single small package

For fans with metal blades it should be possible to detect the passage of the blades with a magnetic sensor in the outer rim of the fan.

Communication is another thing - if you have WiFi look at the ESP8266 boards such as NodeMCU and WeMOS D1. About the cost of an Arduino but with WiFi built in.

I guess my main question is would this board be able to 1: monitor humidity and temperature 2: monitor 3 fan motors 3 : send alarms to a cell phone if temp is above certain temps and fan on/off alarms?

By what I've read I should be able to do it my only limitation is myself at the moment. By trade I am an Electrician with very little electronics experience with even less programming experience. I would love to learn the programming side and can see all the applications I could use it on.

The reason I plan on attemping this is because over the next summer we plan on being away a good bit and I want to be able to monitor my greenhouses remotely. I know that there is already hardware/software outthere to do this but most of it is expensive and goes way beyond what i need. I also would like to tailor fit it to my application.

Any recommendation on where I should start with the programming? I plan on buying a arduino kit to play around with, with my son. I'd like him to get interested in it and learn it also!

Thanks in advance


Arduino links.

For many Arduino PDF document links:
Google >>>- - - - > arduino filetype: pdf

Google >>>- - - - > C++ filetype: pdf

Watch these:

Some things to read:


I started with a basic kit from Sparkfun and they had a tutorial with it that I printed out and worked through the examples, should be similar tutorials here and at Adafruit and others - study each example and play around with each one a bit - do a bit more with the program and such - the trick is to get the basics down first - just like when you started as an apprentice electrician and they had you do some basic skills over and over \

Good luck

Monitoring from a remote location is a pretty big step. You may not get that part finished this year.

I would start with the temperature and humidity. I love the BME280 sensor. But it uses a communication bus that cannot go long distances, so you can't put it near the roof while the Arduino is near the floor. Find a sensor which has a good tutorial, buy it and follow the tutorial.

There are not many sensors that can be read long distance - RS485 or 4-20mA outputs are the most common options, but those sensors tend to be industrial designs with price tags to match.

It's usually cheapest/easiest in the hobby/Arduino world to have Arduinos at the various nodes, and then use wireless links to transmit the data.

That of course adds a whole extra set of layers of complexity: the wireless link itself, the potential difficulty to perform maintenance, and the worry about power management when going battery powered.

I’m working on similar at the moment.

For a number of years, I have used a raspberry Pi, a 5v relay board and 12v solenoid boards to perform watering while I’m away. Due to water pressure, I can’t water all my veg patch and greenhouse all in one so trigger the valves one at the time to split the veg patch into 2 zones and the greenhouse into another. This works on a timer basis, so if the weather is particularly dry it does not give any extra watering. Likewise if it rains a lot (I live in the UK!) while you are away, you run a sprinkler when it is not required.

To take this further, the obvious step is to add a soil moisture sensor, which I initially did by trailing long wires all over the place. A rechargeable battery and/or solar power with a wireless board is a much neater solution. As someone suggested above, the Wemos D1 mini is a great little board for this, it can log up to a data logging service and then my watering Pi can pull back that data before making the decision if it should water or not.

The downside is, I can’t get the D1 working with solar power. A log of my failures and suggestions is in a running forum post here:

See the link at the top of that thread:

This sounds exactly what you want, though I can’t make their circuit work. I decided to also throw in a BME280 (also suggested on this thread), after reading that blog.

It has been an interesting exercise, learning by repeated failure and I have a few other things to try. Eventually I will likely make a blog post of my failures and hopefully final success. If there is nothing useful in the thread, feel free to send me a private message via this forum and I’ll update you how far I have got.

Though, if you have fans in your greenhouse, I’m guessing that is powered so can you get power to a device? That would get around the whole headache of solar and battery. Do you have a sensor or output from the fans to read into a board? Do you have any wireless coverage, or if not how far away is the nearest wireless device?

I’m thinking that an arduino with a radio board linking to a Pi in your house might be a way forward.


it is rather easy to monitor your WiFi enabled bits.

if there is a WiFi nearby, and you have access to it
you can do evryting you want with stuff you can buy.

you can monitor
-the motor AMPs to show it is drawing power (or not)
-soil moisture
-water pressure

all of these in mulptle places.

then post that date on the net
and send you a TXT if one of the parameters are out of tolerance.

I would offer that it would be much easier to have the local device monitor soil and then open a drip irrigation than to wait for you to get a cell signal and water the plants.

Do you have power in your green-house ?
do you have WiFi signal in your greenhouse ?
would you be willing to dedicate a cell phone to be the interface for cell connection ?
do you have water all the time so you can connect a sprinkler valve ?

the WiFi is the easierst because there is so much already done with that for yoru applicaiton
a LoRa is a radio link that may work over greater distances
the Cell link may incur costs for use.

Thanks for all the great info! I'll be reading through all this as I go. My greenhouses are about 10 feet in between them. One is 44' by 100 the other is 32' by 80'. One has 3 fans the other 2. The smaller of the two houses uses a misting system plus fans to cool and maintain a higher humidity level. I live in Mississippi so it gets really hot and a fan failure that goes unnoticed could kill all plants in a greenhouse in a day. I do have wifi close we have a small garden center store that has wifi att uverse. I can get wifi in both greenhouses. If I'm able to do this I plan on automating even farther with wet leaf sensors for our growing portion of our greenhouses. Our plan is to operate the nursery as a seasonal business and do a bit of traveling in early summer and winter. We will have an employee that will work around 14 hrs a week throughout the summer to help monitor and to put new belts on the fans when needed be. This way i could also monitor it and if something goes wrong i could give him a call and get him over.

OK. Wifi in the greenhouse makes it significantly easier.

Are there no commercial solutions to do this? Often you can get some great ideas of what's possible by looking at what's available, even if you don't buy their equipment.

MorganS, Yes, I've looked at some that's available. I found a temp, humidity monitor and logger with wifi that was around 400$. I could get a good setup but it'd cost me around 2 grand for everything I want to do. I am looking into doing it myself cause 1. I'd like to be able to do it. 2. I see so many other things I could use this on. 2. I also would like to get my son into something other than xbox. I think he would find this fun especially if i get a kit that makes a small robot or car.

there are quite a few arduino greenhouse projects on the web.
start with an ESP8266 and a BME280 (think "E" means everything) the BMP280 is temp and "P"ressure only, not humidity

an Arduino UNO with an EmonTX shield


will easily show fan motor amperage.

PaulRB has done some of the work PaulRB link
check out his pages

I'm thinking that you don't particularly need to monitor the fans themselves (as that sounds hard), but do need to monitor temperature and send an alarm.

Although I have not used it, a friend is a big fan of MQTT ( This is an internet of things messaging broker. He did a nice demo of a long strip of neopixels, then in a techtalk at work, each person who visited a site with a mobile phone got control of one pixel. MQTT was the bit in the middle.

It sounds like you need to monitor the temperature and humidity (BME280 or DHT11), send to a data logging service for graphing (graphs are always good to look at), and if a threshold is hit MQTT can be used to send a message to an alerting system.

dave-in-nj suggested an ESP8266. I really like the Wemos D1 mini which is pretty much a small arduino with the ESP8266 wireless chip. You could have one in each greenhouse doing the temperature logging, then use MQTT to trigger alerts via mail and/or an alert box in your store. With that you could get very inventive.

Use another D1 Mini for your in-store box, but look at some of the outputs you can get. A buzzer and silence button is one option, but with the likes of Neopixels (or WS2811 LEDs, similar just not Adafruit branded) you could scale the colours getting redder the hotter it is and flash if an alert is triggered. These come as strips, matrix and rings. You could show a pattern or basic message on a matrix. LED matrix is also another consideration.

If you really got carried away, put another couple of sensor probes about, one in your store and one outside then you could have a display customers could see.

I'm looking for a starting kit. I'm looking at some of thise Elegoo kits. I'm just wondering how if I should just get the board and sensors I want for my project and start there.

THis is the kit i was looking at :Elegoo EL-KIT-008 or something like it. Anyone have opinions on that brand?

It is hard to say to not get a kit, but since it does not fit your listed goals, much of it is not needed.

since we all have shoe boxes full of stuff we bought but never used, having more than you need today, often means you have bits later on.

for WiFi, get a WEMOS DI mini or pro. get a couple of them.

get a few DS18B20 temperature sensors with the 2 or 3 meter leads and some with 1 meter leads.

get an extra UNO, and an emonTX shield for your motor monitoring with some current sensors.

since part of your plan is to wean the youngster from the X-Box, go over some of the ideas with him and see what peaks his interest in the project. get him started with the bits he gravitates towards.

lay out the whole list of things you want to to do, then see where you want to start.