Bluetooth Electronic Shelf Label Development Services with nRF54L & PAwR

What are the Advantages of Using nRF54L for Electronic Shelf Labels?

nRF54L15 is a wireless SoC with low energy consumption powered by 128 MHz Arm Cortex-M33 processor. It has also 1.5 MB of non-volatile memory, 256 MB of RAM, and 2.4 GHz radio. The Nordic manufacturers have specifically indicated that the nRF54L series supports Bluetooth capabilities including Bluetooth PAwR and ESL profile.

This means that this device is a convenient tool for ESL design that requires handling data transmission wirelessly, managing display features, monitoring batteries, ensuring security, etc., inside one small embedded product.

Moreover, nRF54L15 has a variety of features such as an advanced security system, various serial connections, ADC, timers, PWM, etc.

However, selecting the SoC is only one part of the engineering decision. Display type, refresh frequency, battery capacity, antenna design, store environment, tag density, update latency, enclosure, and access-point placement all influence the final design.

Bluetooth ESL and PAwR Development

Periodic Advertising with Responses (PAwR) is especially applicable when it comes to electronic shelf labels since it allows synchronous and connectionless one-to-many communication.

Instead of being connected through individual conventional BLE connection to each label, an access point can broadcast periodic advertising messages and give opportunities to respond to those devices in a synchronized manner.

According to Nordic's ESL materials, PAwR and Encrypted Advertising Data can be utilized in situations when an access point has to handle large quantities of low-energy ESL devices.

The Bluetooth ESL Profile builds application-level behavior on top of Bluetooth LE. The Bluetooth SIG defines it as the mechanism through which a GATT Client can control and update electronic shelf labels using Bluetooth wireless technology.

The standardized profile is intended to support interoperability within the ESL ecosystem.

Our development work can cover PAwR synchronization, ESL addressing, response-slot handling, command processing, acknowledgement logic, display updates, and device-state management.

nRF54L ESL Firmware Development

We develop ESL tag firmware around the real operating cycle of a retail label.

The common features of firmware include:

Power management is a central part of the architecture. The tag should remain inactive whenever no useful work is required and wake according to its communication schedule, process the required data, update the display when necessary, and return to a low-power state.

Relevant Adequate Infosoft Nordic Experience

Adequate Infosoft has developed multiple Nordic-based BLE and low-power embedded products, providing relevant engineering experience for ESL projects.

nRF52840

Nordic nRF52-Powered BLE Smart Lock

Our BLE smart-lock project used Nordic nRF52840 hardware, a custom four-layer PCB, low-power motor control, battery management, secure BLE communication, OTA support, and mobile/cloud integration. Advanced firmware versions used Nordic nRF5 SDK and Zephyr.

Although this was not an ESL project, it demonstrates relevant experience in secure BLE communication, event-driven firmware, low-power operation, custom Nordic hardware, and production-oriented development.

Read Case Study

nRF52832 / nRF52840

nRF52 Smart Watch for Healthcare and Fitness

Adequate Infosoft developed a production-oriented smartwatch using Nordic nRF52832 and nRF52840 devices. The project included low-power RTOS firmware, BLE communication, sensor integration, power-state management, custom RF hardware, and manufacturing-ready prototypes.

These capabilities are transferable to ESL tags where compact hardware, predictable BLE behavior, and aggressive power management are equally important.

Read Case Study

Nordic nRF52

BLE Smart Ring with Nordic nRF52

Our Nordic BLE smart-ring project focused on compact embedded hardware, gesture recognition, touch interaction, haptic feedback, BLE communication, low-power optimization, and EVT bring-up.

The project demonstrates experience with the same class of constraints found in small ESL devices: limited physical space, battery operation, event-driven firmware, wireless communication, and careful power optimization.

Read Case Study

These case studies demonstrate relevant Nordic and BLE engineering experience. They are not represented as nRF54L or Bluetooth ESL implementations unless explicitly identified as such.

E-Paper and Display Integration

The display subsystem is one of the most important ESL-specific engineering areas. E-paper technology is particularly attractive for many shelf labels because the image can remain visible without continuously refreshing the display.

We integrate display controllers with nRF54L firmware and can build image-processing pipelines for product prices, promotional messages, product identifiers, barcodes, QR codes, icons, and other retail information.

Development may include full and partial refresh strategies, frame-buffer management, image compression or conversion, font rendering, display-driver integration, and handling of incomplete or interrupted updates.

The software architecture can connect the retail backend to the display pipeline so that a price or promotion change is transformed into the appropriate label image or command before being transmitted to the target ESL.

Low-Power ESL Design

One of the fundamental requirements for design of electronic shelf labels is battery life. Hence, wireless communication must be designed properly according to the wakeup and update cycles.

Among those optimized are:

• PAwR timings and receive windows
• Sleep and active mode states
• Display refresh
• CPU activity
• Memory reaching
• Peripheral usage
• Battery check
• Retrial behavior
• Firmware logging

The nRF54L Series is intended for low power wireless operation, with Nordic identifying the nRF54L15 as exceptionally low power SoC. Its radio and processor architecture contains everything necessary to support battery-powered equipment while being energy efficient.

These assumptions are confirmed on the basis of actual hardware rather than simply relying on theoretical values. Current profiling, timing of communication, display behavior, and battery discharge are combined in order to make the final assessment of practical operating time of the label.

ESL Access Point and One-to-Many Communication

A production ESL system normally includes three major layers: the ESL tag, the access point, and the retail management platform.

The access point schedules communication with tags, handles wireless traffic, manages synchronization, tracks responses, and forwards application information between the ESL network and the retailer's backend.

We can develop or integrate access-point software using embedded Linux, gateway platforms, Nordic development hardware, or other suitable computing systems.

For larger deployments, communication scheduling becomes important. A practical system needs to support device grouping, queued updates, retry handling, acknowledgements, unavailable tags, and priority-based updates.

For example, an urgent pricing correction may need to take precedence over a routine synchronization task. The management layer can also identify labels that repeatedly fail to update and flag them for store-level investigation.

Retail Backend and Fleet Management

The ESL system is not just a label. The software necessary for all ESL functionality needs to connect all data within an organization across existing systems.

Integration with POS, ERP, inventory and pricing management systems can be accomplished by means of REST APIs, MQTT, webhooks, and other similar technologies.

The following is an illustration of how that works in practice:

A price changes inside the retailer's system and goes into the device update queue. The defined access point finds the required device and establishes communication. The ESL receives the update, processes it, and confirms success.

The backend can keep track of the device ID, firmware version, battery state, last communication date and time, update status, and additional conditions.

This makes the ESL solution a fleet of devices instead of a set of independent beacons.

Security in Bluetooth ESL Systems

Security is crucial as an unauthorized change in a price or promotion can lead to serious business disruptions.

Ensuring security in Bluetooth ESL systems requires the use of Encrypted Advertising Data (EAD), while implementing provisioning with security components, credential protection, authenticated firmware upgrades, authorization at the application level, and key management practices.

nRF54L15 also has several features that could protect hardware, such as Arm TrustZone, tamper detection, and cryptography with side-channel protection.

Moreover, communication security is regarded as different from business authorization. Even though the data was found to be secure, the application still has to ensure that the sender and command that have reasonable requests are allowed to change a particular tag or store.

PCB, RF and Hardware Development

Adequate Infosoft can support the complete embedded hardware surrounding the nRF54L15.

The engineering areas include:

In general, nRF54L15 utilizes a single-ended antenna output with the integrated balun but it is worth mentioning that the real RF performance depends on how the antenna is designed and how the PCB implementation and other adjacent components will be used.

From ESL Prototype to Production

We provide comprehensive support for ESL programs, starting with the initial proof of concept and moving forward through engineering production.

On the development path, we can assist with different areas such as the system architecture, nRF54L evaluation, PAwR implementation, Bluetooth ESL integration, display selection, PCB design, firmware, an access-point software, retail APIs, and security architecture, among others.

When it comes to the prototype, the main focus is on demonstrating the PAwR communication and display control. In the case of a production rollout, however, the focus shifts to achieving tag density, reliability, battery life, fleet management, secure updates, manufacturing repeatability, and long-term maintainability.

Why Choose Adequate Infosoft?

Adequate Infosoft combines embedded firmware, Nordic BLE development, PCB and RF engineering, mobile applications, backend development, cloud integration, and IoT product engineering.

ESL can't be thought of as simply another standalone product. Its various components of communication protocol, display, battery, access point, back end, retail information, security controls, and manufacturing all need to act together as one combined system.

We're able to work towards measurable engineering targets, such as battery life, update latency, communication reliability, tag density, display refresh, recovery performance and testing of manufacturing.

We can assist with an nRF54L15 PAwR proof of concept, Bluetooth ESL firmware, custom electronic shelf label hardware, ESL access points, e-paper solutions, and its entire architecture and production.

Frequently Asked Questions