RAPcore Documentation

RAPcore stands for Robotic Application Processing Core, and seeks to develop high-performance hardware to enable the next generation of robotics application. The project was started by Ultimachine and Synthetos, two companies that have innovated technologies such as the RAMPS board, RAMBo, and jerk controlled kinematics in low-cost additive and subtractive systems.


3D printers as one of the first ubiquitous robots, but there is far more value in automation and digital manufacturing technologies that has yet to be unlocked to the average person. RAPcore leverages recent advancements in technology to help accomplish this:

  • Open Source FPGA synthesis

  • Open Source formal verification

  • Open Source RISC-V CPUs

  • Advanced motor control and kinematic algorithms

To start, the project is focused on FPGA hardware for high performance closed-loop motor control. These early iterations will prove-out the hardware and RAPcore gateware. Similarly, we will greatly reduce the computational overhead on microcontrollers by coordinating step sequences and commutation. This will lead to a suitable middle ground of price and performance based upon our analysis. By fusing the step timing and commutation logic into a single element (the FPGA) we allow for smaller and more efficient micro controllers, and on the drive side we allow for greater flexibility and power output of motor driver circuitry.

Feature Overview

The basic features of RAPcores is as follows:

  • Onboard stepper motor commutator

  • Fixed Point Step-Timing Algorithm

  • High-speed Quadrature Encoder Accumulator

  • High-Speed SPI Bus