Closed Loop Smart Stepper
The MisfitTech’ smart steppers turn a stepper motor into a closed loop servo.
The Smart Steppers uses a high-speed 32-bit processor combined with a 14bit (16384 pulse per revolution) encoder and motor driver to provide a closed loop PID control of the stepper motor.
Features
- Open source hardware
- Open source firmware
- Fixed point math for highest reliability
- High speed digital step and direction interface
- 256k flash, 32k SRAM
- Arduino compatible firmware
- Positional PID control
- Velocity PID control
- Hybrid Positional PID control
- On board Motion Planner for standalone operation
- Level shifted logic interface to work with 3.3V and 5V motion controllers
- Extra serial (UART) interface for connecting to external controllers
- Optional LCD for easy setup and configuration
- Command line interface through USB port for configuration and firmware updates
Seed the User Manual for specifications and installation instructions
Firmware and hardware design can be found on github here
Arduino Install Instructions for compiling firmware and loading onto board.
Drivers for the USB serial port are here. On some windows system since the driver is not signed you might need to do the same steps as outlined here to install the driver.
The Nano Zero Smart Stepper Comes with:
- PCB shown above with bootloader programmed
- LCD - optional
- Magnet for gluing to motor shaft
- Four 40mm M3 screws
- M3 plastic washers for spacing boards from stepper motor
Currently the open source firmware supports:
- LCD based calibration
- LCD calibrations testing
- Support for both error and enable pins on latest hardware
- Support for up to 256x microstepping
- Automatic detection of motor rotation, and step size. Currently only supporting 1.8 and 0.9 degree/step motors
- Command line interface (like DOS/BASH) through USB
- No recompile of firmware for calibration or parameter/PID changes
There are several blog posts about the firmware and development on this site, additionally see the following google group for peer support if needed:
https://groups.google.com/forum/#!forum/smart-stepper