The initial version of the AI Audio Classifier Recycle Bin project only uses a breakout PCB stepper driver. The motor driver and the Audio Classifier model inference are both run using a single microcontroller (Arduino Nano BLE Sense).

This upgrade offloads the stepper motor, servo motor, and IoT connectivity, so the main microcontroller just run the audio classifier inference and the result will be sent to the microcontroller that is onboard the PCB. All the manufacturing (gerber) files and KiCAD design files are included in the "Files" section of the project page.

This new PCB also includes a buck converter, to supply 5V for both microcontrollers from a 3S LiPo battery. 12V from the battery is used for powering the stepper motors through the TMC2208 stepper driver.

The design allows for switching to different microcontroller dev boards in the Arduino MKR and Portenta family, because they use a similar styled pinout pins. In this case, I'm using the Arduino Portenta C33 because we will use internet connectivity through WiFi. Here are some other options you can choose from:

Arduino MKR WiFi 1010 or Arduino Portenta C33 for WiFi

Arduino MKR WAN 1310 for LoRaWAN

Arduino MKR GSM 1400 for GSM Cellular