Connecting a new sensor to your WiFi
Adding a sensor, or moving one to another room? The device sets up its own WiFi through a short setup screen on your phone. No app, no cable. Below you will read exactly how it works and which network settings are the most reliable.
A sensor that cannot find its network opens its own setup page
When you power on a new sensor for the first time, or move an existing sensor to a place with a different network, it can no longer find its known WiFi. Instead of staying silent, the device then automatically starts its own temporary WiFi network with a setup page behind it. You connect your phone to it, pass on your WiFi details, and as soon as the sensor connects that setup network disappears again by itself.
Why this works nicely
You do not have to install anything or plug in a cable. A relocated sensor first tries its old network again (in case it was only a brief outage), and then opens the setup by itself. That way you never lose a sensor: it simply waits until you give it a new network.
Connecting in four steps
The setup screen below appears on your phone as soon as you connect to the sensor’s temporary network. On most phones it opens by itself, just like a login screen in a hotel.
Connect to the setup network
Look in your WiFi list for a network that starts with FairGrow-setup and connect to it. This network does not need a password.
The setup screen opens
On most phones a window appears automatically. If not, open your browser and go to 192.168.4.1.
Choose your network and enter the password
Select your WiFi from the list of found networks, or type the name manually, and enter the password. Pay close attention to capital letters and special characters.
Done
The sensor saves your details, restarts briefly and connects to your network. The setup network disappears and the sensor starts measuring.
WPA2 and 2.4 GHz: the settings that work reliably
The sensors run on the ESP32, a widely available microcontroller. It connects most reliably on WPA2-PSK (AES) and on the 2.4 GHz band. Set your access point to this and pairing goes smoothly.
Does a sensor connect, but keeps dropping?
That is often caused by the security mode. On a network that only uses WPA3, or on a mixed WPA2/WPA3 mode where Protected Management Frames (PMF) are mandatory, the sensor does find the network, but the last step of connecting fails (the handshake). Set the network to WPA2-PSK and it is usually fixed right away. This looks like a wrong password, so always check that the password is exactly correct too.
In short
Security on WPA2-PSK (AES/CCMP), band on 2.4 GHz, and PMF set to optional instead of mandatory. That is the combination our sensors connect to most stably.
And 5 GHz? For sensors usually not a good idea
We do get the question whether it is not more modern to run on 5 GHz.
Here are both sides, honestly.
What is available
The ESP32-C5 is the first RISC-V microcontroller with dual-band Wi-Fi 6 on both 2.4 and 5 GHz, plus Bluetooth 5 LE and IEEE 802.15.4 (Zigbee 3.0, Thread). All classic ESP32s, the C3 and also the C6 we use as a coordinator are stuck on 2.4 GHz.
Boards are readily available by now: Seeed offers a XIAO ESP32-C5, Waveshare an ESP32-C5-WROOM-1 devkit, and Olimex has one too. So dual-band is possible on this hardware, technically speaking.
Why we advise against it for garden, greenhouse and field
5 GHz physically has a shorter range and penetrates walls, glass, crops and humid air worse than 2.4 GHz. In a greenhouse or in a field, exactly your scenario, that is the opposite of what you want. Your sensors often hang far from the access point. On 2.4 GHz you cover that distance, on 5 GHz probably not.
On top of that, in the EU you work on 5 GHz with DFS channels (radar detection). Because of that an access point sometimes suddenly switches channel, after which your sensors have to reconnect. For devices that need to keep measuring quietly day and night, that is inconvenient.
Our choice
For range and stability we deliberately choose 2.4 GHz. If you do want to use dual-band hardware, the ESP32-C5 is an option, but keep in mind that on 5 GHz you often have to stay closer to the access point.
Connecting a sensor, frequently asked questions
My sensor will not connect, what can I check?
Check three things: is your network set to WPA2-PSK (not WPA3 or mixed with mandatory PMF), is it a 2.4 GHz network, and is the password exactly right? A failed handshake often looks like a wrong password.
The setup screen does not open by itself.
Connect your phone to the FairGrow-setup network and then open your browser manually at the address 192.168.4.1. If needed, turn off mobile data for a moment so your phone does not send the request over the mobile network.
Does 5 GHz really not work?
On special hardware such as the ESP32-C5 it can. But for range in garden, greenhouse and field we recommend 2.4 GHz, because that signal reaches further and penetrates walls, glass and crops better.
Do I need to install an app?
No. Setting up is done entirely through your browser, on any phone or laptop. No app is needed.
What happens if I move a sensor to a different network?
The sensor first briefly tries its old network. If it cannot find it, it opens the setup screen again by itself, so you can pass on the new network. See also open ESP32 hardware and the right sensor in the right place.
Ready to expand your measurement network?
Tell us about your location and we will think along about the sensors and the network that fit. We are happy to set up a no-obligation pilot for you.