MKS SERVO57B is 3d printer closed loop stepper motor NEMA23 MKS SERVO57 developed by Makerbase that prevents losing steps. CPU is STM32F103CBT6 ARM 32-bit Cortex™-M3 CPU Core,72 MHz. Magnetic encoder is Allegro's A1333LLETR-T Contactless 0° to 360° angle sensor IC ,12bit .This Project open source hardware and code,support platformio build and upload firmware... - View it on GitHub