Single Pair Ethernet, the industrial networking standard that runs 10 Mbit/s over a single twisted pair, now has a proper Raspberry Pi on-ramp. Germany-based Brechel Electronic has released two HAT+ compliant expansion boards that leverage MAC-PHY chips with mainline Linux kernel drivers, meaning the boards appear as standard network interfaces under Raspberry Pi OS with full ethtool support.
The two models target different use cases within the IEEE 802.3cg specification. The BE-IIS-HPP-T1S uses a Microchip LAN8651 MAC-PHY for 10BASE-T1S multidrop networking, supporting up to eight nodes on a shared bus over distances of 25 meters (82 feet) with PLCA collision avoidance. The LAN865x driver family covering the LAN8651 entered the mainline kernel in Linux 6.12, with 6.13 extending that support to the B1 silicon revision. The BE-IIS-HPP-T1L swaps in an Analog Devices ADIN1110 for 10BASE-T1L point-to-point links over much longer runs, with galvanic isolation rated at 2,250 V DC. The ADIN1110 driver has been in the mainline kernel since Linux 6.1. Both boards measure 65 x 56 mm (2.6 x 2.2 inches) and draw roughly 35 mA at 5 V.
The boards belong to Brechel's BE-IIS HAT++ stacking ecosystem, which solves the usual SPI and GPIO conflict headaches when combining multiple industrial HATs on a single Pi. The system supports stacking up to five different HATs or three of the same type, with a management IC handling automatic detection and persistent configuration. An optional Power over Single Pair Ethernet add-on HAT can supply up to 1 A at 9 to 33 V input. The company's open-source installer on GitHub handles Linux driver installation, Device Tree overlays, and system services automatically. A DigiKey TechForum thread documents building an industrial field switch and gateway that uses the stacking system to bridge legacy fieldbus protocols such as CAN and RS-485 with Single Pair Ethernet.
The T1S model is compatible with the Pi 2, 3, 4, 5, Zero, and Zero 2 W, while the T1L variant supports the Pi 3, 4, 5, and Zero 2 W. The BE-IIS-HPP-T1S is priced at $115 (€96) and the BE-IIS-HPP-T1L at $135 (€113), both shipping from Germany.
