StepFish: fischertechnik I2C stepper motor controller

thingiverse

StepFish is a highly advanced stepper motor controller for the Fischertechnik construction toy system, powered by an ATmega328 microprocessor. This versatile device can be used as a standalone controller or as an I2C master, offering unparalleled flexibility and control. Key hardware features include: * Up to four steppers driven by StepStick/Pololu carrier boards or compatible alternatives, connected via pin headers * Fischertechnik-compatible connectors for two active low endstops per stepper axis * Three PWM pins for custom uses like servos, LEDs, or interrupt pins in I2C slave mode * An I2C connector compatible with the ftDuino and Fischertechnik TX controllers * A serial connector for programming or monitoring the ATmega328 with a USB-serial/TTL/FTDI adapter * Fischertechnik-compatible connectors for 5V in (chip logic) and stepper motor power A DC-DC step-down 5V converter can be added internally to the enclosure if desired, allowing the controller to be powered from the motor pins only. Other notable features include a print-in-place reset button and two status LEDs for 5V and stepper motor power. The ZIP file contains fritzing, gerber, and PDF files for producing the one-sided PCB, which uses my patented printed flush sleeve design (Printbuchse) for Fischertechnik typical 2.6mm jacks. Soldering can be a bit tricky due to the connector pins being placed at the bottom of the PCB. Warning: Ensure that your carrier boards' current is limited as described in various online resources, such as Pololu's FAQ or Arduino forums. My enclosure provides access to the carrier boards' potentiometers from the bottom, allowing for easy measurement using an alligator clip attached to a screwdriver and one of the GND-pins. At present, StepFish can only be used as a standalone controller or with custom I2C firmware, as the StepFish firmware is still under development. The planned firmware will be based on the AccelStepper library, offering an I2C-wrapper to provide AccelStepper functionality over I2C, along with additional endstop configuration and optional servo/interrupt functionality. If you appreciate my work, please consider leaving a "like" or posting your make as a token of appreciation. You can find my other Fischertechnik designs on Thingiverse, and a video showcasing StepFish in action is available on YouTube.