British electronics specialist EduTech has launched an STM32-based development platform built specifically for wearables, with integrated microphones and nine-degrees-of-freedom (9DoF) inertial measurement unit (IMU): the BlueSense4.
Designed as the successor to the company's earlier BlueSense, the BlueSense4 is built around STMicro's STM32L496 running at a stock 20MHz and up to 80MHz with 320kB of static RAM (SRAM) and 1MB of flash storage. To this, EduTech has added two on-board sensors: An ICM-20948 nine-degrees-of-freedom (9DoF) IMU which it claims offers lower power consumption than the part used in the original BlueSense, and a pair of digital microphones for ambient sound pickup.
For external hardware, the wearables-focused platform includes two digital microphone inputs, a 12-bit analog-to-digital converter (ADC), a 12-bit digital-to-analog converter (DAC) with firmware-driven signal generation capabilities. The same pre-loaded firmware includes what the company describes as "multimodal sensing," allowing for immediate capture of motion data, sound, and external ADC inputs for storage to SD Card or streaming over USB or Bluetooth without additional programming.
"As a wearable platform, BlueSense is a tiny device which can be used to capture body movement and orientation with a 9DoF motion sensor," the company explains. "The platform provides access to the raw data of the 3D accelerometer, 3D gyroscope and 3D magnetometer. It also provides the device orientation in quaternions in an earth coordinate system."
"The platform can acquire data from the built-in digital microphones at 8KHz or 16KHz. The microphones are spaced to enable broadside or endfire arrays with a nominal frequency of 8KHz. The actual microphone array algorithm has to be implemented by the user (e.g. post-recording)."
The BlueSense4 is available now on the EduTech Tindie store, priced at a hefty $499.