Digitization of Commerce
How to use electronic price labels effectively?
Introduction
The easiest way to digitize commerce is to start the changes with simple but useful things. Among others, one example would be electronic price labels (ESL), which can be useful in small as well as large stores. It is a fully scalable product:
- In small (single neighborhood stores), the label management system can be a simple smartphone application provided by the label producer, but also a web application
- In larger stores with their own ERP systems, we can expand the smart label system to include integration with ERP systems
- In hypermarkets, on the other hand, we can expand the smart price label system with smart store functionality. In this case, the customer will be able to take products from the shelf without going to the checkout. This is when weighing shelves and image recognition mechanisms that can supervise individual shelves of items can come in useful.
Electronic price labels, in addition to the undoubted advantages of, for example, the virtual possibility of changing prices (which can, after all, change frequently due to inflation), provide a number of additional opportunities that would never appear with standard labels. Electronic labels are perfect for dynamic price changes. We can also use them for promotions, where prices change depending on various time dependencies, as well as for happy hour promotions, where the price for a selected product is reduced only during selected hours. Electronic labels also prove helpful for other types of time-based promotions, i.e. night sales, when the price is changed at specific times.
Another example of the use of ESL can be unusual actions in reference to the premise of the promotion. For example, in a given supermarket, a selected label changes color or decor at a certain time, and if a particular customer finds a product with such a label, he or she wins it. In addition, in this case, it would be possible to combine such a mechanism with the mechanism of a smart store, where we can automatically find out how many people have won a particular product and stop the promotion after a certain number of taken products.
Price labels — case study
The development of smart price labels is a relatively difficult challenge, as there are quite high standards for this type of solution.
- The device should be battery-powered, so that there is no need to pull power cables, and so that it can be disassembled like classic labels — without having to replace shelves and reorganize the store infrastructure
- The device should run on a battery for at least a few years, so that there is no need to change batteries frequently, which can be a relatively logistically difficult and expensive task in the case of a large number of labels
- The device should communicate by radio, so that there is no need for communication cables. In addition, the range of this communication should be reasonably large, since large-format stores sometimes have very extensive areas
- The device should look attractive to the customer; it should be fairly small and aesthetically friendly
- The network infrastructure of the labeling system should be able to integrate with both small stores that do not have any management systems and large stores that have sophisticated ERP systems
- It should also be able to cooperate and expand with other smart store systems
- The device should be relatively inexpensive — in small stores it may be a few dozen labels, while in large stores the number may already exceed thousands.
So as we can see, the ESL-related requirements for hardware and software are relatively large. But let’s first refer to the requirements for wireless transmission. Currently, there are at least a dozen wireless transmission protocols on the market for data transfer, among which we can mention: GPRS/4G/5G, Bluetooth, WIFI, ZigBee, ZWave, etc. In everyday life, we most often encounter the first three standards. Today, virtually all of us have a smartphone or laptop equipped with the aforementioned wireless communication protocols. At first glance, it would seem that the use of these technologies should be the simplest, because in this case, using standard devices it will be easy to carry out communication with the mentioned labels, for example, equipping them with Bluetooth or WIFI communication we would not need basically any additional infrastructure. Unfortunately, none of the listed wireless communication protocols will be suitable for this type of application. For example, the popular WIFI standard has high power consumption, which basically disqualifies it from battery-powered devices. In addition, it is quite computationally complex and requires adequate resources.
Another popular protocol that we could use for communication is Bluetooth. We can specifically mention the newer BT-LE standard, which meets the assumptions about energy efficiency. This would even be an interesting option when implementing a project for small stores, as popular smartphones, tablets or laptops, for example, could be used to communicate with labels. However, the use of this protocol means that the design of price labels is not scalable, and this type of labels will not be suitable for the implementation of projects in stores with a large area. Limitations in this case will be, for example, the limited range of the radio path and the inability to build extensive networks based on BT, such as those equipped with more gateways.
A much better solution in this case seems to be the LoRAWAN standard developed by the American company Semtech. LoRA has been optimized for the lowest possible power consumption and extended range. The network itself allows communication over long distances of 2–3km in open space and makes it possible to build wide area networks based on multiple gateways.
In addition, the protocol itself is optimized for battery power thanks to adaptive adjustment of transmitter power and radio path parameters. The disadvantage of this solution is the need for dedicated gateways, but the standard is now strongly developing, and gradually public LoRAWAN networks are already being established in Europe and the States, organized, for example, by mobile operators, so that in the future it is very likely that with access to public networks (in the case of small stores) it will be possible to use the labels without the need to purchase gateways. Besides, nowadays gateways are fairly cheap, so they can be purchased at quite reasonable prices.
Another important aspect is the selection of appropriate electronic components, so that the device has low power consumption and is relatively cheap to manufacture. The most popular solution encountered so far has been the purchase of a dedicated IC for radio transmission and a microcontroller which are connected, for example, via an SPI (Serial Peripherial Interface). This type of approach is good, but it requires the purchase of two separate ICs which makes the product unnecessarily more expensive and increases the size of the device. After a number of searches, it turned out that there are specialized chips on the market that contain an integrated microcontroller and radio path in a single housing, which can be used for the LORA protocol. This would be the best solution to use in the mentioned project.
With the LORAWAN protocol and the ability to build wide area networks based on multiple gateways or public networks, and the right architecture, the project will scale accordingly. Let’s take a look at the figure below, which we prepared showing an overview architecture of the system for small stores.
In the primary version, all price labels via a single gateway will connect to the LORA-WAN (in the case of an available public network, the gateway can be declined). The gateway then connects to the Lora cloud server (TTN or Amazon). In turn, dedicated applications, whether installed on a smartphone or directly from a computer browser, will connect to the corresponding cloud services, which can be directly managed by the store owner.
In the case of large stores, the labels connecting to the network will be much more and — naturally — in the case of large areas, the gateways for connecting to LORA-WAN may also be several or a dozen.
All labels connect to the LORA network, where in the cloud we additionally have additional applications needed for large stores:
- as before, it can be a price management application
- Integration API with the store’s ERP system
- optionally, there can be an additional service and application for the store user, where all relevant information can be displayed, such as promotions, etc.
In the case that a large store decides to implement additional functionality, then the system can be equipped with additional weighing shelves and a video surveillance application to supervise the process of independent shopping without going to the checkout.
In addition to the system architecture and hardware solutions, the software platform for the embedded device is particularly important, as its smooth operation will depend on it. This is the least tangible part of the project for the user, but one that requires quite a lot of work.
The first important issue is the device’s ability to run on battery for a long time. The platform should provide adequate power management so that the processor is in the highest possible power-saving state for most of the time cycles, while individual functional blocks that are not used should be automatically put to sleep.
Another crucial aspect is the possibility of automatic updates. As is well known, software is written by humans, so it is fraught with the possibility of errors. For this reason, it should be possible to update software in any embedded device. Thanks to the FUOTA (Firmware Update Over The Air) protocol, which is part of the LORA standard, we have the possibility to update software via a radio path. Due to the limited bandwidth of the radio path, updates are sent to all devices simultaneously in broadcast mode, with appropriate data redundancy (ECC).
Today, an incredibly important aspect is embedded software security. More and more embedded devices are connected to the network, and they are increasingly becoming a vector of attack — due to the fact that designers of built systems have not previously put particular focus on this aspect.
The software platform designed by our team provides a special emphasis on security. The processor used guarantees safety through a secure boot mechanism, where only firmware signed with private keys can be run. In addition, the updates themselves are also cryptographically secured, so you have the assurance of both safety and quality by choosing us to execute the digitization of commerce.
Words by Lucjan Bryndza, Head of Embedded Pillar at Altimetrik Poland
Copywriting by Kinga Kuśnierz, Content Writer at Altimetrik Poland
