STMicroelectronics – Complete SP1ML sub-1GHz modules provide easy means to add RF connectivity to an application


The SP1ML enables wireless communication between IoT nodes in the home

STMicroelectronics’ SP1ML series is a series of low-power, full-featured RF modules operating in licence-free bandwidth at frequencies below 1GHz. The modules allow the user to easily add wireless capability to any electronic device without requiring in-depth RF experience.

The SP1ML-868 operates in the 863-870MHz Short Range Devices (SRD) frequency band, and the SP1ML-915 in the 902-928MHz ISM band.

The 14mm x 13.4mm modules are based on ST’s SPIRIT1 RF transceiver with integrated switch-mode power supply. They also integrate an STM32L1 low-power microcontroller, a BALF-SPI-01D3 868/915MHz balun with built-in harmonic filter, and an antenna and crystal.p5_STM_img1

The module may be configured with simple AT commands to set operating parameters such as the data-transmission rate and RF output power. Certain GPIOs and peripherals on the STM32L1 are also available for interfacing to external devices in the user’s application.

The modules are CE-compliant and FCC-certified. The modulation schemes supported by the SP1ML modules are 2-FSK, GFSK, GMSK, OOK and ASK.


  • Supply-voltage range: 1.8V to 3.6V
  • Up to 11.6dBm output power
  • Up to 500kbits/s data rate
  • Operating-temperature range:
    -40°C to 85°C


  • Home and building automation
  • Wireless sensor networks
  • Data-acquisition equipment
  • Security systems
  • Mobile health and medical devices
  • Industrial monitoring and control systems
  • Wireless meters
  • IoT devices



The STEVAL-SP1ML868 is a USB dongle for the SP1ML- 868 SPIRIT1 low-power RF module. The dongle includes the module itself and a USB connector to a PC, which also powers the dongle. Firmware supplied with the dongle by ST enables the user to create a SPIRIT1 link using simple AT commands.

Orderable Part Number: STEVAL-SP1ML868