STMicroelectronics STEVAL-FKI915V1

Overview

STEVAL-FKI915V1 from STMicroelectronics is a Sub-1GHz RF evaluation board integrating the S2-LP transceiver (860–940 MHz), STM32L152RE MCU, external SkyWorks SE2435L power amplifier, SPI/USB interfaces, and -130 dBm receiver sensitivity - designed for wireless M-Bus and Sigfox system prototyping.

For engineers reviewing the STEVAL-FKI915V1 datasheet, STEVAL-FKI915V1 pinout, STEVAL-FKI915V1 application, or STEVAL-FKI915V1 equivalent, this board supports rapid validation of ultra-low-power sub-GHz communication stacks with programmable +27 dBm output, 0.3–500 kbps air data rates, and integrated protocol engine for ACK/retransmission.

Technical Context

The board implements a complete RF development platform where the S2-LP transceiver handles physical layer modulation (2/4-FSK, GFSK, OOK, ASK) and baseband protocol offload, while the STM32L152RE MCU executes host firmware, manages SPI control, and provides ST-LINK/V2-1 debugging via USB. The SE2435L PA enables +27 dBm output in the 860–940 MHz ISM band.

Low-duty-cycle RX/TX operation and automatic packet handling (ACK, timeout, retransmission) are hardware-accelerated in the S2-LP; RF filtering uses discrete LC networks on both TX and RX paths, and antenna selection is controlled via GPIO-driven RF switches.

Key Specifications

Availability

STEVAL-FKI915V1 is available at Aetrix Electronics and suitable for wireless utility metering, industrial sensor telemetry, smart city infrastructure, and LPWAN gateway validation requiring stable component supply and full-stack RF development support.

Supply support for STEVAL-FKI915V1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, analog ICs, MEMS, and power devices for industrial, automotive, and IoT applications.

This board belongs to ST's STEVAL (ST Evaluation) product line - purpose-built to accelerate RF subsystem validation, protocol stack integration, and regulatory pre-compliance testing for sub-GHz wireless applications.

FAQ

Does STEVAL-FKI915V1 support over-the-air firmware updates?

Yes - the integrated ST-LINK/V2-1 debugger provides USB-based firmware flashing and real-time debugging of the STM32L152RE MCU. While the S2-LP transceiver firmware is preloaded, users can update host application code via SWD or UART bootloader, enabling field-deployable feature enhancements without hardware changes.

Can STEVAL-FKI915V1 operate in ETSI EN 300 220-compliant mode?

Yes - the S2-LP transceiver is certified for ETSI EN 300 220-2 V3.1.1 (2017-05) in the 863–870 MHz band. The board's RF layout, filtering, and PA biasing meet spectral mask and spurious emission limits when configured per ST's AN4903 application note and reference firmware.

What antenna options are supported?

The board provides two SMA connectors (ANT1 and ANT2) and an onboard RF switch controlled by GPIO to select between them. It supports 50 Ω monopole, dipole, or PCB trace antennas tuned for 868 MHz. Matching network components (L/C values) are populated for 868 MHz but can be modified for 915 MHz operation per design note DN0017.

Is the S2-LP protocol engine compatible with wireless M-Bus Mode T?

Yes - the S2-LP's hardware-accelerated packet engine supports Mode T framing (EN 13757-4:2018), including Manchester encoding, CRC-16, and variable-length payload handling. ST provides validated M-Bus stack libraries and GUI tools that configure the transceiver registers and timing parameters to meet Mode T timing tolerances and preamble detection requirements.