The Vreden-based KEMPER GmbH, a manufacturer of filter systems for welding fumes, is a Datacake customer and runs (in association with another company) a vaccination center, as well as a corona testing station, in its home town.
To monitor the refrigerators that store the valuable and sensitive vaccine, as well as equipment for the Corona quick tests, they set up a LoRaWAN-based monitoring system together with Datacake.
In this blog post, we explain exactly how we went about it, what the setup entailed, and how much it cost.
Video on YouTube
In May 2021, we recorded a video for The Things Conference - The Things Stack Edition where we set up this exact setup (the Vaccine Center Monitoring) on Datacake and The Things Stack V3.
You can find the video here:
The items in the Overview
Between the individual locations (vaccination center and quick test station) the setup looks the same, only the number of installed sensors differs. The following list gives an overview:
- RAKwireless RAK7268 WisGate Edge 2 as LoRaWAN Gateway
- 1NCE prepaid IoT SIM card for cellular connection
- The Things Stack v3 as LoRaWAN network server
- Dragino LHT65 temperature and humidity sensor
- Datacake IoT platform for monitoring and alerting
LoRaWAN Gateway as the Basis
Battery-powered LoRaWAN sensors are used to record temperatures. In order for these sensors to be able to transmit their measured values to the Datacake platform, either an existing LoRaWAN network or a small indoor gateway is required to set up a LoRaWAN network on site.
To ensure that the projects at the test station as well as at the vaccination center can be implemented smoothly, we provide a LoRaWAN gateway for both deployment sites. Here we use the new WisGate Edge 2 products from our partner RAKwireless.
This gateway is relatively new and not only comes with many features for professional (and industrial) use in commercial applications, it
Who wants to learn more about the gateway:
Plug and Play thanks to LTE
Often, the infrastructure at the place of use is not known in detail. For example, rapid test stations are often set up in locations where there is no Internet, and in the case of the vaccination center, there was no public WLAN on site that could have been used.
In our projects, we therefore like to equip the gateways with LTE mobile communications and use SIM cards from the provider 1NCE, which provides a so-called IoT prepaid tariff that comes with 500 megabytes of data volume and a 10-year term.
Learn More: https://1nce.com/de/features/
As a big advantage, we don't have to ask for access data for the WLAN and don't have any further requirements for the infrastructure on site, except that one or two sockets are needed for the power supply.
Integration on The Things Stack V3
For the use of a LoRaWAN gateway and associated sensors, you need a LoRaWAN network server, or LNS for short. This manages the individual sensors with corresponding gateways and sends the actual user data (measured values) to an IoT platform (Datacake in this case).
In this project, we used the gateway and sensors via The Things Stack V3 network server from The Things Industries.
See more at:
We own our own instance of the company's commercial network server, as it allows us to ensure that we have higher availability (SLA of 99.9%) compared to the free and gratis community edition.
Use of Battery-powered Sensors
The actual sensor used to measure the temperature is an LHT65 and comes from the Chinese manufacturer Dragino, which is known for producing high-quality IoT products.
Due to its compact dimensions of about 7 x 3 x 2 cm and the integrated battery with a long lifetime of 5+ years, it is perfect for monitoring temperatures in a wide range of applications.
In addition to its internal measuring unit, the LHT65 offers optional connection for an external temperature probe (or other sensors, such as brightness).
Activation via a pushbutton on the sensor is all that is required for commissioning. Thanks to an integrated battery with a runtime of up to 5 years, no external power supply is required. A boon for installation.
Precise measurement of Temperature and Humidity
The LHT65 has an integrated measuring unit from Sensirion, a company known for manufacturing high-quality sensors, and is thus able to measure temperature and humidity.
A big plus of the sensors is the high accuracy of the measurements. This is also due to the fact that the sensors are calibrated at the factory. If you put all the sensors next to each other, the measured values hardly deviate from each other.
Also the tolerances amount to +/- 0.5°C in the worst case, which we could never determine however even in most diverse projects. Here, the tolerances were within a range of +/- 0.2°C.
Installation was quite simple. Using a double-sided adhesive pad, the sensors were glued to a side wall inside the refrigerator. This means that the sensors can not only be removed without leaving any residue, but no modification is required for installation and the gluing process is completed in just a few seconds.
No false Readings
Thanks to the low energy consumption and the fact that the sensors switch off completely between transmission intervals, there is no falsification of the measured values (e.g. due to potential heating of electronic components).
Incidentally, this can be seen as a general advantage of LoRaWAN sensors over WiFi or mobile radio. On average, the electronics of a LoRaWAN sensor are only switched on for a few seconds.
A connection establishment as with WiFi or mobile radio does not take place at all. After about 1 second, the message is completely transmitted and the sensor sleeps for the next 5 minutes.
Good Signal Penetration
Now you may wonder if installing the sensors inside a well-insulated refrigerator won't cause problems with transmission.
Compared to WiFi or cellular radio, LoRaWAN uses a radio signal with a frequency of 868 MHz and thus has physically much better penetration of solid materials, including metal or concrete.
Direct integration of sensors in refrigerators is therefore no problem. At the same time, it is possible to supply an entire building with a LoRaWAN network using just one gateway.
Public Dashboard on Datacake IoT Platform
On site, the status of the refrigerators is to be displayed on a monitor for visitors and employees of the vaccination center in the form of a real-time dashboard.
For this purpose, we created a tenant for the vaccination center on the Datacake platform and created a global dashboard there that visually displays the current temperatures as well as trends.
Trends provide Information on Status
In addition to the real-time display of the measured values, the temporal developments of the temperatures are also indicated in the form of percentage changes. This allows a very concrete statement to be made about the condition of the cooling system.
QR Code for Easy Access
To ensure that employees and interested parties also have access to the dashboard, stickers were created with a QR code that can be scanned by smartphone and leads to a mobile version of the dashboard.
Logging into the Datacake platform is not required to view this dashboard.
Critical Condition Alerting
In addition to the dashboard, alerts for critical temperature deviations have also been created using the Datacake platform's rule editor.
Here, various thresholds are specified and when these are exceeded, SMS and email notifications are sent to employees (or other responsible persons).
Daily Data Export of Measured Values
Another function of the Datacake platform is used for monitoring the measured values, namely the automated export of daily data as a CSV file, which is sent to employees by e-mail at a defined time.
Thus one has not only a copy of the measured data, but receives also automatically a printable report, which one can use in the case of a proof then without necessary access to the platform, in order to import this e.g. into an Excel evaluation.
The largest cost factor in the list is the LoRaWAN gateway. Therefore, one should check if there is not the possibility to use a WLAN or wired intranet on site for the connection of the gateway (in order to be able to fall back on the cheaper non-mobile variant) or if there is perhaps already a LoRaWAN network on site.
Especially when using several measuring stations in the same location, it is worthwhile to set up an outdoor gateway at a suitably high point (such as a church, building, etc.) in order to achieve wide-area coverage.
The costs at a glance.
- 6x Dragino LHT65 = approx. 180 Euro
- 2x RAKwireless Gateway = 260 Euro WiFi / 450 Euro Cellular
- 1x Datacake IoT Platform = 200 Euro (annual fee)
The total cost for both deployment sites (vaccination center as well as rapid test station) is approx. 650 Euro (WiFi) or 830 Euro (cellular).
Thanks to cost-effective LoRaWAN sensor technology as well as easy-to-use gateways, which do not place any requirements on the infrastructure at the deployment site due to a mobile radio option, 24/7 monitoring solutions can be implemented very quickly, easily and cost-optimized.
An IoT platform (such as Datacake) can be used for monitoring and alerting critical conditions. These bring out of the box dashboards and rule creation for critical condition notifications.
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