For testing advanced industrial IoT applications, ST Microelectronics offers a wireless industrial node, which they call the STWIN SensorTile. This development kit from ST amplifies prototyping of applications like predictive maintenance and condition monitoring.
The STWIN SensorTile kit has a core system board, using a microcontroller operating at ultra-low power. The microcontroller can analyze vibrations from motion-sensing data across 9 degrees of freedom. The vibrational data may cover a wide range of frequencies. The spectra can cover very high-frequency audio including ultrasound. It is also capable of monitoring local temperature and environmental conditions at high precision.
The user can also tie up the core system board with a wide range of embedded sensors of industrial-grade type. To aid in speeding up design cycles for providing end-to-end solutions, ST compliments the development kit with a rich set of optimized firmware libraries and software packages.
An on-board module on the kit provides BLE wireless connectivity. Users can connect a special plugin expansion board to get Wi-Fi connectivity. Those who require wired connectivity for their projects can use the onboard RS485 transceiver. ST has a host of daughter boards using the STM32 family. This includes the LTE Cell pack. Users can connect these compatible, small form factor, and low-cost daughter boards to the development kit through an on-board STMod+ connector.
Along with the core system board, the wireless industrial node kit also has a protective plastic case, a Li-Po battery rated for 480 mAh, a programming cable, and a STLINK-V3MINI programmer cum debugger for STM32.
Users can employ a comprehensive range of sensors available with the core system board. ST has specifically designed these sensors to enable and support industry 4.0 applications. The microcontroller has various serial interfaces for communicating with these sensors. The interfaces include SPI for communicating with motion sensors with high data rates, and I2C for communicating with environmental sensors and magnetometers. The microcontroller can directly communicate with analog and digital microphones.
When interfacing with analog microphones, a low-noise opamp amplifies the signal. An internal 12-bit ADC is available in the microcontroller for sampling the output from the opamp. A digital filter manages the signal output from digital microphones. The microcontroller has a Sigma-Delta modulator interface for signals from digital microphones.
The core system has several sensors on the board. These include a digital MEMS microphone of industrial grade, a wideband MEMS analog microphone, an ultra-low-power 3-axis magnetometer, a high-performance ultra-low-power MEMS motion sensor, an ultra-wide-bandwidth MEMS vibrometer up to 5 kHz, a 3D accelerometer and 3D gyro IMU with a core for machine-learning, a high-output current rail-to-rail dual opamp, a digital low-voltage local temperature sensor, a digital absolute pressure sensor, relative humidity and temperature sensor.
The ultra-low-power microcontroller in the STWIN core system board is a part of the STM32L4+ series of MCUs. The series is based on the ARM Cortex-M4 core, which is of the high-performance 32-bit RISC type. The processors operate up to 120 MHz, and the board has 2 MB Flash memory, along with 640 Kb SRAM. The board has several connectivity options of both wired and wireless types.
