Embedded IoT Networking

Embedded Cellular Hardware From a Single UK Supplier

Embedded IoT deployments cover a wide range of integration approaches: a Raspberry Pi gaining cellular capability for an edge gateway prototype; a digital signage installer specifying compact industrial gateways for a national rollout; an OEM designing cellular connectivity directly into their product PCB at the manufacturing stage. Each approach has different hardware requirements, different commercial structures, and different technical decisions to make.

Millbeck supplies embedded cellular hardware across all three approaches, with UK stock and the technical guidance to specify the right product for each project. Whether you’re building a prototype, integrating cellular into an existing product, or designing connectivity into a new product from day one, our team can match the hardware to the deployment.

In short: Millbeck supplies three categories of embedded cellular hardware. The Teltonika Calyx HAT+ module range (4G Cat 4, 5G RedCap, full 5G NR) plugs directly onto a Raspberry Pi 4 or 5 via the 40-pin GPIO header for SBC-based deployments. The Teltonika TRB140 and wider TRB gateway range provides compact industrial 4G/5G gateways available either as complete cased products or as board-only units for OEM integration. Proroute’s H685 and H820 router boards are available for OEMs designing cellular connectivity directly into their products at the PCB level. All three approaches pair with Millbeck IoT SIMs and industrial antennas for a complete embedded connectivity stack.

Three Approaches to Embedded Cellular

Choosing the right embedded approach depends on the deployment context, the integration timeline, and the volume economics.

Raspberry Pi HAT+ modules suit projects that already use a Raspberry Pi as the compute platform, particularly for prototyping, low-volume production, and applications where the Pi’s software ecosystem and community matter. The HAT+ form factor mounts directly on the Pi via the GPIO header, integrating mechanically and electrically without USB dongles or external adapters. The Teltonika Calyx range is the embedded HAT+ option that brings industrial-grade Teltonika modem technology to the Pi platform.

Compact industrial gateways suit projects that need a complete cellular gateway in a small form factor, available either as a cased product for direct deployment or as a board-only unit for OEM integration into a larger enclosure. The Teltonika TRB140 is the typical entry point: 4G LTE Cat 4 connectivity, Gigabit Ethernet, RutOS firmware, two configurable I/O lines, and ultra-compact 64.5 x 74.5 x 25mm dimensions. Other TRB series products (TRB141, TRB142, TRB143, TRB145, TRB245, TRB246, TRB256, TRB500) offer different interface options and 5G capabilities for specific application requirements.

OEM board-only routers suit projects where cellular connectivity is being designed into the product at the PCB level, typically with manufacturing volume that justifies the engineering effort of board-level integration. Proroute’s H685 and H820 router boards provide complete cellular router functionality (4G CAT4/CAT6 or 5G with Gigabit Ethernet) that OEMs can integrate directly into their product, eliminating the bolt-on cellular module and the associated cable, power, and enclosure overhead.

For most projects, one approach is clearly the right fit. For projects in early feasibility or prototyping, our team can advise on which approach matches your integration timeline and volume economics.

The Teltonika Calyx HAT+ Range

The Teltonika Calyx is Teltonika Networks’ first embedded systems product, launched in late 2025 specifically for Raspberry Pi 4 and 5 deployments. The HAT+ form factor mounts directly on the Pi via the 40-pin GPIO header, replacing the unreliable USB dongle and improvised cellular adapter approaches that have historically compromised Pi-based deployments.

Calyx 4G Cat 4 provides 4G LTE Cat 4 connectivity (up to 150 Mbps download, 50 Mbps upload) with fallback to 3G and 2G. Two SMA antenna connectors. USB 2.0 data transfer to the Pi. The cost-effective entry point for IoT applications with low to medium data throughput, including smart metering, remote sensors, payment terminals, kiosks, and digital signage.

Calyx 5G RedCap provides 5G NR Reduced Capability connectivity, delivering 5G’s reliability and lower latency at significantly lower power consumption and cost than full 5G modems. Two SMA antenna connectors. USB 3.0 data transfer. Documented eSIM support alongside the Nano SIM slot. Ideal for medium-throughput IoT applications where 5G’s improved performance matters but full 5G’s bandwidth and power profile is overkill.

Calyx 5G NR provides full 5G New Radio connectivity for the most demanding embedded applications. Four SMA antenna connectors for full 5G MIMO performance. USB 3.0 data transfer. Suitable for HD video streaming, real-time control applications, edge AI inference, and any deployment where 5G’s full performance profile is required.

All three variants share -40°C to +75°C industrial temperature range, GPIO modem control, PCM audio support, Nano SIM slot, and the credit-card form factor that matches the Raspberry Pi mechanical envelope.

The Teltonika TRB Industrial Gateway Range

The Teltonika TRB series provides compact industrial cellular gateways for embedded deployments where a complete gateway is needed but the cased Calyx HAT+ form factor isn’t appropriate.

TRB140 is the typical entry point: 4G LTE Cat 4 connectivity (up to 150 Mbps), Gigabit Ethernet port, Micro-USB data and power, 9-30V DC industrial power input with reverse polarity and surge protection, two configurable digital I/O lines, passive PoE support, RutOS firmware with full VPN (IPsec, OpenVPN), firewall, RMS support, and FOTA updates. The 64.5 x 74.5 x 25mm form factor and -40°C to +75°C operating range suit it to indoor industrial deployments and OEM integration into larger enclosures.

The TRB series extends to additional models with different interface options:

TRB141, TRB142, TRB143, TRB145. Variations with RS-232, RS-485, CAN bus, and other industrial interfaces.

TRB245, TRB246. Extended I/O and dual-Ethernet variants.

TRB256. 5G NR variant for higher-bandwidth applications.

TRB501. Extended capability for specific industrial requirements.

The TRB range is available in standard cased form (with PSU, antenna, and packaging) for direct deployment, or as board-only units for OEM integration into custom enclosures and products. For OEMs, board-only purchase eliminates the unnecessary cost of a case that will be discarded or replaced during integration, and simplifies the BOM.

Proroute Board-Only Routers for OEM Integration

Proroute has explicitly positioned itself as an embedded cellular specialist for OEMs and manufacturers, with board-only versions of their H685 and H820 router products available for integration directly into customer products at the PCB level.

H685 board variants are available across the H685 product line: the H685 4G Cat 4 (100 Mbps), H685 4G Cat 6 (300 Mbps with carrier aggregation), and H685 5G (Gigabit Ethernet, full 5G connectivity). Each provides complete router functionality (cellular modem, Wi-Fi, dual Ethernet, embedded firmware, VPN, firewall) on a board suitable for direct integration into a custom product enclosure.

H820 board variants add additional Ethernet ports to the standard router functionality, suiting applications that require multiple cabled connections from the cellular gateway. Used in deployments including CCTV systems with multiple cameras, energy monitoring with multiple endpoints, and digital signage with multiple displays.

For OEMs, board-only Proroute integration eliminates the overhead of a separate cellular gateway: no extra wiring between the cellular gateway and the main product, no separate power supply, no second enclosure, and no second item in the BOM. The cellular connectivity becomes part of the product’s mechanical and electrical design from day one.

Choosing the Right Embedded Approach

For most projects, the right embedded approach is clear from the deployment context. Some general guidance:

Choose Calyx HAT+ when: the project uses Raspberry Pi as the compute platform, prototype or low-volume production, the Pi’s software ecosystem matters, the deployment fits within an indoor or cabinet enclosure, the application benefits from Linux compatibility and standard Pi peripheral integration.

Choose Teltonika TRB cased when: the deployment needs a complete, ready-to-use cellular gateway in a compact form factor, indoor or cabinet installation, no PCB-level integration required, RutOS management and RMS integration are valuable, the volume doesn’t justify board-only OEM integration.

Choose Teltonika TRB board-only when: the project is OEM integration into a custom enclosure, the cased version’s form factor doesn’t fit the target product, volume justifies eliminating the case from the BOM, full RutOS firmware is required.

Choose Proroute board-only when: the project is OEM integration with PCB-level cellular requirement, the design includes the cellular electronics directly in the product, manufacturing volume justifies the engineering effort, Proroute’s specific feature set (CAT4/CAT6/5G options, dual Ethernet, integrated Wi-Fi) matches the requirement.

For projects that don’t fit cleanly into one category, our pre-sales team can specify a hybrid approach combining multiple form factors across different parts of the deployment.

Combining Embedded Hardware With the Connectivity Stack

Embedded cellular hardware delivers the most value when paired with the right connectivity, antennas, and management architecture.

Millbeck supplies embedded hardware alongside the rest of the connectivity stack: IoT SIMs (UK roaming for multi-carrier resilience without dual-SIM hardware, global roaming for international deployments, eSIM or eUICC for long-life applications), industrial antennas matched to the embedded form factor and deployment environment (compact MIMO, adhesive, puck, and embedded antennas suit different installation scenarios), and the cabling, mounting, and enclosure considerations specific to each application. For OEMs at scale, we also support pre-deployment configuration, BOM consolidation, and the supply chain accountability that production manufacturing requires.

For prototyping projects we can supply individual units; for production deployments we can support volume orders, framework agreements, and multi-year supply contracts.

Where Embedded IoT Hardware Is Used

Common embedded IoT deployment scenarios span multiple verticals where compact, integrated cellular connectivity is essential:

Smart city infrastructure. Environmental monitoring, traffic systems, public Wi-Fi access points, and street furniture connectivity where the embedded form factor matters because the deployment location is space-constrained or visibility-sensitive.

Digital signage and information displays. LED signage, retail displays, transport information systems, and outdoor advertising where the compute and cellular connectivity sit inside the display housing rather than in a separate cabinet.

Payment terminals and kiosks. Self-service kiosks, EV charge point displays, ticket machines, and retail payment terminals where cellular backhaul is integrated directly into the customer-facing hardware.

Industrial monitoring and SCADA. Plant monitoring, machine telemetry, and remote facility management where the embedded cellular sits inside the industrial equipment cabinet with the PLCs and sensors it monitors.

Edge IoT gateways. Sensor aggregation, protocol bridging, and edge analytics deployments where embedded compute and connectivity replace separate gateway hardware.

OEM product integration. Manufacturers building cellular connectivity into their own products at the design stage, ranging from agricultural monitoring equipment through medical devices to specialist industrial machinery.

Vehicle and transport applications. In-vehicle telemetry, fleet monitoring, and specialist transport applications where the cellular hardware is integrated into the vehicle’s electronics rather than added as a separate module.

Frequently Asked Questions

What Is Embedded IoT Hardware?

Embedded IoT hardware refers to cellular connectivity components designed to be integrated directly into a larger product or deployment, rather than installed as a separate cellular gateway in its own enclosure. This includes Raspberry Pi HAT+ modules that mount on the Pi via the GPIO header, compact industrial gateways available as board-only units for OEM integration, and full router boards designed for direct PCB-level integration into custom products. The common requirement is reliability and integration suited to industrial deployment, rather than the bolt-on approach used for general-purpose connectivity.

What Is the Teltonika Calyx?

The Teltonika Calyx is an industrial-grade cellular HAT+ module designed for the Raspberry Pi 4 and Raspberry Pi 5. It’s Teltonika Networks’ first embedded systems product, launched in late 2025, and provides 4G LTE, 5G RedCap, or full 5G NR connectivity to Pi-based embedded deployments. The HAT+ form factor mounts directly on the Pi via the 40-pin GPIO header. Three variants (4G Cat 4, 5G RedCap, full 5G NR) cover different bandwidth and power requirements.

Can the Teltonika TRB140 Be Purchased Board-Only?

Yes. The Teltonika TRB140 is available either as a complete cased product (including the gateway, PSU, antenna, micro-USB cable, and DIN-rail mounting hardware) or as a board-only unit suitable for OEM integration into a custom enclosure or product. Board-only purchase makes sense for OEMs building production deployments at scale, where the standard case will be replaced or discarded during integration. For confirmation of board-only availability and pricing for specific TRB models, contact our team directly.

Does Proroute Offer Board-Only Routers?

Yes. Proroute has explicitly positioned itself as an embedded cellular specialist, offering board-only versions of their H685 (4G Cat 4, 4G Cat 6, and 5G variants) and H820 (additional Ethernet ports) router products for direct integration into OEM products. This eliminates the cellular gateway as a separate item in the deployment, with the cellular electronics integrated directly into the customer product’s mechanical and electrical design. Proroute also provides antenna selection guidance, RF placement support, and OEM-specific commercial structures (volume pricing, framework agreements, multi-year supply contracts).

What Is the Difference Between a HAT+ Module and a Board-Only Router?

A HAT+ module is designed specifically for the Raspberry Pi platform: it mounts on the Pi’s 40-pin GPIO header, integrates mechanically with the Pi’s form factor, and works with the Pi’s software ecosystem. A board-only router is a complete cellular router (with its own processor, firmware, and feature set) supplied without an enclosure for OEM integration into a custom product. The HAT+ approach assumes the Pi is the compute platform; the board-only router approach assumes the cellular router is the compute platform with the OEM’s product peripherals connected to it.

Does Millbeck Support OEM Volume Orders for Embedded Cellular Hardware?

Yes. For OEMs and manufacturers building production deployments, we support volume pricing, framework agreements, multi-year supply contracts, BOM consolidation across cellular hardware, IoT SIMs, and antennas, and pre-deployment configuration where useful. Our team can engage at the early prototyping or feasibility stage to specify the right hardware approach, then support the project through to production manufacturing and ongoing operational supply. For specific commercial structures or volume requirements, contact our team directly.

Can I Use Multi-Network Failover With Embedded Hardware?

Most embedded cellular hardware uses a single SIM slot, so hardware-level dual-SIM failover is not typically supported. For multi-carrier resilience, Millbeck recommends pairing single-SIM embedded hardware with multi-network roaming SIMs that connect to whichever UK carrier has the strongest signal at any given moment. This approach provides carrier-level resilience without requiring dual-SIM hardware, and typically delivers better real-world reliability than dual-SIM failover because the SIM platform handles carrier selection automatically. For specific applications where hardware-level dual-SIM is required, our team can advise on alternative form factors.

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