Timing Pulley 2GT 18x5mm 20 Teeth rob0114 Yes—the 40-pin GPIO

Yes—the 40-pin GPIO

I2C View product PWM Servo 16-Channel 12-bit Shield I2C interface Adafruit general servo motion control PWM

Keep the controller ground and motor-driver ground common

SiLabs chips seem to have better driver stability and can handle very high speeds and 'unusual' non-standard baud rates

Timing Pulley 2GT 18x5mm 20 Teeth rob0114 Yes—the 40-pin GPIOMechanical Motion Parts for Better Fit, Drive, and Alignment The Timing Pulley 2GT 18x5mm 20 Teeth is a practical motion hardware from Circuitrocks for students, makers, and repair friendly builds. It fits well in projects that need mechanical fit and mounting, while keeping setup straightforward for testing and prototype work. Compared with generic parts, this product stands out through details such as 20 Teeth, 18x5mm. That makes it a solid choice