Understanding the Bluetooth® wireless connection
These are Clever Logger loggers
Loggers measure temperature (and, sometimes, humidity). They are generally placed in fridges and freezers.
This is a Clever Logger gateway
The gateway connects to your office internet and provides a link between your loggers and the Clever Logger database in the cloud.
Loggers and gateways use Bluetooth® LE to communicate with each other
Loggers use Bluetooth® to broadcast their current temperature, like a smart phone broadcasting music to a speaker.
The gateway can “hear” these broadcast temperatures.
The gateway will sometimes send settings and requests back to the loggers.
In theory, Bluetooth® LE can go up to about 100 metres
That’s about the length of a football field. And that’s probably the only place where you might get close to this range.
In reality, the range is probably closer to 15 metres
In a building, things like walls, furniture and fittings will all contribute to reducing the range of the signal.
So, how far can a logger be from a gateway?
That’s tough question, because it depends a lot on what is in-between the two devices.
Here’s a good rule of thumb…
If the gateway is in the same room as the logger, it will ALMOST CERTAINLY work.
If it is in the next room, it will PROBABLY work.
If it is in the next room, it MIGHT work.
If it is any further than that, it PROBABLY WON’T work.
There will be exceptions, but in general, this is a good guide.
You can easily check the signal strength between the loggers and the gateway
On the Locations page of the Clever Logger Dashboard, you can set your View to Detailed by using the dropdown in the top right of the page. More info
This will show you extra details for each logger, including the signal strength.
Remember that the signal strength updates only every few minutes, so if you make a change, you will have to wait a little bit to see it reflected.
So, what's a good signal strength?
If your signal strength is less than 40%, you should expect to get occasional offline alarms.
If it is less than 15%, you will probably get frequent offline alarms.
If I am getting offline alarms from my logger,
how do I improve signal strength?
There are two ways to improve signal strength:
1. Move the gateway closer to the logger, or
2. Remove obstacles in between.
Let’s look at these individually…
Moving the gateway closer to the logger
If you have an Ethernet connection closer to the logger, then you can move the gateway
Removing obstacles between the gateway and logger
Surfaces can stop or weaken wireless signals.
Brick, plaster, cement, metal, stone, and double-glazed glass may create issues with signal strength.
Avoid having your logger and gateway surrounded by them.
Wireless signals can bounce off certain surfaces.
Certain materials will reflect wireless signals.
Relying on signals bouncing is not guaranteed.
A gateway in one position may not receive a signal, but when angled in a different way, can respond clearly, like a telephone call.
Standing in one place could cause a bad signal, but moving a couple of steps away, can significantly improve the call.
Water will drown wireless signals.
Wireless signals wont go through water, this is important with condensation over the logger.
They obviously won’t work underwater. They are also not water proof!
Rain will also shorten the range.
Ice will “freeze” wireless signals.
Wireless signals wont go through snow and ice. This is a problem in freezers where icing over and condensation can occur.
How to improve the signal
- Remove obstructions surrounding the Logger: if possible, remove anything around the Logger. Make sure to move the Logger AWAY from metal objects
- Reposition the Logger: Try moving the Logger closer to the front of the fridge or towards the seal. Make sure the Logger is AWAY from any metal surfaces
- Avoid any obstacles that may be in the way such as walls, shelving or furniture that may interfere with the signal. Obstacles can be avoided by moving them or positioning your Gateway to a higher position.
- Remove obstructions surrounding the Gateway: Don’t place the Gateway behind or in a metal object (computers, server boxes or cupboards)
- Reposition the Gateway: Try moving the Gateway closer to where your Logger. This is possible by connecting the Gateway to WIFI or using a longer network cable.