STMicroelectronics STEVAL-SP1ML915

Overview

STEVAL-SP1ML915 from STMicroelectronics is a USB dongle evaluation tool for the SP1ML-915 915 MHz sub-GHz RF module, integrating SPIRIT1 transceiver IC, on-board antenna, USB-powered operation (4.5–5.5 V), and AT-command interface for rapid RF link setup. It serves as a PC-connected development interface for low-power wireless sensor node prototyping in ISM band applications.

For engineers reviewing the STEVAL-SP1ML915 datasheet, STEVAL-SP1ML915 pinout, STEVAL-SP1ML915 application, or STEVAL-SP1ML915 equivalent, this page delivers verified layout details, I/O pad mapping, firmware interaction model, operating condition limits, and evaluation-specific design constraints - all confirmed from ST's official DocID027158 Rev 1 data brief.

Technical Context

The dongle implements a hardware abstraction layer between a host PC and the SPIRIT1-based SP1ML-915 RF module via CP2102 USB-to-UART bridge, enabling serial AT command control without external level-shifting. All RF signal paths are impedance-matched to 50 Ω, and the onboard antenna is tuned for 915 MHz operation with typical peak gain of –1.2 dBi.

It supports two firmware modes: default AT command interpreter and reprogrammable SPIRIT1 configuration via SWD pins (SWCLK/SWDIO) and BOOT0. Power delivery is regulated to +3.3 V for the module using an integrated LDO, with current monitoring enabled through configurable jumpers.

Key Specifications

Availability

STEVAL-SP1ML915 is available at Aetrix Electronics and suitable for wireless sensor network prototyping, IoT gateway validation, and sub-GHz RF interoperability testing requiring stable component supply and documented evaluation infrastructure.

Supply support for STEVAL-SP1ML915 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, Switzerland, designing and manufacturing microcontrollers, analog ICs, MEMS, and RF solutions for industrial, automotive, and consumer markets.

This dongle belongs to ST's STEVAL (ST Evaluation) platform family, engineered specifically to accelerate time-to-proof-of-concept for SPIRIT1-based sub-GHz RF designs - not for end-product integration.

FAQ

Is STEVAL-SP1ML915 qualified for mass production deployment?

No. ST explicitly states this board is a demonstration tool only, not qualified for end-product use. It lacks regulatory certifications (FCC/CE), long-term reliability validation, and production-grade mechanical robustness. It must be replaced by a certified module or custom design before commercial release.

What firmware options are supported on the SP1ML-915 module inside the dongle?

The dongle ships with factory-loaded AT command firmware. Users can reprogram it via SWD using ST-LINK or compatible debuggers, loading custom SPIRIT1 configurations or proprietary protocol stacks - confirmed by BOOT0 pin control and SWCLK/SWDIO pad access per DocID027158.

Can the onboard antenna be replaced or bypassed for external antenna testing?

No dedicated U.FL or SMA connector is provided. The PCB antenna is directly routed from the SP1ML-915 RF output; however, pads 1–14 include RF-related signals, and the schematic shows test points near the antenna feed - enabling probe-based external coupling but not hot-swap replacement.

Does STEVAL-SP1ML915 support both SP1ML-868 and SP1ML-915 modules interchangeably?

No. STEVAL-SP1ML915 is hardware-specific to the SP1ML-915 (915 MHz) variant, with R13 populated per schematic. The STEVAL-SP1ML868 uses R12 and different antenna tuning - they share layout and firmware architecture but are physically and electrically distinct boards.