PeskyProducts, Tlera Corp Launch Open-Hardware STM32 Firefly Bluetooth Low Energy Dev Board
Available to order as a PCB from OSH Park or a completed unit from Tindie, this compact Arduino-compatible aims to make BLE a cinch.
PeskyProducts and Tlera Corp have designed an open-hardware development board for Bluetooth Low Energy (BLE) projects, built around STMicro's STM32 microcontroller and boasting full Arduino IDE support: the Firefly BLE.
"This is a small, open source hardware implementation designed to make using and customizing the STM32WB55 easy for everyone," Tlera Corp explains of the Firefly BLE's design. "It supports iBeacon, NUS, BlueST protocols as well as standard and custom BLE services and characteristics.
"For several years we have been making use of ST's STM32L4 family of ultra-low-power MCUs in a variety of applications including development boards, asset trackers, and environmental monitors. Often we include a BMD-350 (nRF52) module for BLE connectivity with smart devices like Android and IOS phones, etc. With the new dual core STM32WB55 MCU, we can now make devices similar in cost, size, and functionality to those we have been but also have the added benefit of embedded BLE connectivity."
The Firefly BLE includes an Arm Cortex-M0+ core in charge of handling the Bluetooth Low Energy communications stack while a 64MHz Cortex-M4F core is free for user applications; the system-on-chip includes 256kB of static RAM (SRAM) and 1MB of flash. The board carrying it, meanwhile, breaks out 21 of the chip's general-purpose input/output (GPIO) pins at the edge in a breadboard-friendly stick-style layout.
The design is self-contained, with no need for an external antenna: A PCB antenna is claimed to offer BLE connectivity over 50m line-of-sight (around 164 feet). The board ships with an Arduino core, making it programmable via the Arduino IDE, and supports Peripheral mode now with Central and combined modes to follow.
The board design files have been published by PeskyProducts to OSH Park, where the PCB can be ordered for $12 or the Gerbers downloaded for production elsewhere; Tlera Corp, meanwhile, is selling fully-assembled units on Tindie priced at $29.95.