I've tested different microcontrollers for running the Audio Classifier inference (and DSP). The project initially uses the Arduino Nano 33 BLE Sense for inferencing and Actuator controls. Since now I have upgraded the PCB to include an additional microcontroller for driving actuators, there is more flexibility to switch between different microcontrollers for running inference.

In this log I will discuss about using the Seeed Studio Xiao nRF52840 sense (In the next log I will focus on the Arduino Nicla Voice). Since the Xiao nRF52840 Sense dev-board uses the same nRF52840 with the Arduino Nano 33 BLE Sense, the same Arduino code can be reusable without making any changes.

My Edge Impulse Project for the Seeed Studio Xiao nRF52840 Sense: https://studio.edgeimpulse.com/public/289422/latest

The difference between this Edge Impulse project and the original one is the data acquisition for this one was using the Xiao nRF52840 Sense. Technically the original one should work, but I just redo the process since now I'm using the filter foam and case, so the audio sample can be a little bit different.

The 3D printed case is designed very similarly compared to the case for the Nicla Voice, the difference is on the hole placement for the microphone, the cutout for the built-in LED indicator, and the cutout on the bottom for the header pin layout. Between the top case and the Xiao nRF52840 Sense I placed a small sheet of foam to filter wind noise and other unwanted noises.

Female header pins soldered to female ESLOV connector is used for connecting the Xiao nRF52840 Sense to the actuator microcontroller. These two microcontrollers will communicate via I2C.

The inference microcontroller is hot swappable, in this case I'm swapping the inference microcontroller from the previously connected Nicla Voice to the Xiao nRF52840 Sense.