The Smart Steppers use the AMS AS5047D with 14bit resolution.
The Smart Steppers and Mechaduino are very similar in design with a few exceptions:
Smart Stepper exposes an error pin
Smart Steppers includes a buck converter to power board off the motor voltage
Smart Steppers have an LCD option, such that they can be configured without use of PC
Smart Steppers do not require recompiling source code to calibrate motors or change parameters.
Smart Steppers firmware has a lot more features an options.
Smart Steppers hardware has diodes and TVS for ESD issues.
Smart Steppers come with screw cage connectors for easier connection to machine.
Smart Steppers parameters are easy to change through USB serial port using a command line interface.
The ustepper does not control the current to motor like the Smart Steppers and Mechaduino. The ustepper basically uses a step stick to step forward or back to correct errors. The Smart Steppers and Mechaduino will change the current to the motor based on the error, this reduces noise and heat on motor.
With the Smart Stepper when you connect to machine and try to move the head out of position the current control on the motor makes it feel like strong springs are attached to the head pulling it back into position. Since you have control over the current you can change the "stiffness" of these virtual springs.
I have ported my firmware to the Mechaduino in case people want to upgrade their Mechaduino.
Trampas
www.misfittech.net