Hi! Hi! I'm Jakub, and I'm a 16-yo high school student. OpenParol is my original, open-source controller project (perhaps I'll create others in the future?), along with custom software for both the controller and a PC. The PCB serves as a 6-DOF robotic arm controller, tested and used with the Parol6. It features six TMC5160T Pro drivers and a section containing two galvanically isolated CAN-FD buses, which can be used for communication with external (or future) modules and controllers. It also includes an isolated I/O section for connecting limit switches (both mechanical and NPN inductive types), as well as two galvanically isolated outputs and inputs (one of which supports an MCU interrupt).

The board is powered by 24V DC and includes reverse polarity and inrush current protection. Power for the 5V rail is supplied via a buck converter, while the 3.3V rail uses an LDO regulator.

The control unit is an STM32G474VET6 - an ideal choice for this type of controller - featuring multiple SPI buses, dual CAN-FD interfaces, numerous timers, and a CORDIC unit that enables rapid interpolation of incoming data. The MCU also supports SWD and Full-Speed ​​USB-C connectivity. Future expansion options include adding external Flash memory via the SPI4 interface, for instance, to store permanent arm configuration settings.

The controller features two galvanically isolated CAN-FD buses (currently sharing a single DC-DC converter to save costs, though they can easily be split into two independent, isolated power sections) and includes a galvanically isolated I/O section. The ISO1228 module allows for the connection of limit switches (both tactile and NPN inductive types) and two E-STOPs (connected to the STM32's EXTI pins, enabling the MCU to respond rapidly to incoming signals via interrupts). Additionally, the user has access to two programmable, galvanically isolated inputs (one of which can also be linked to an EXTI pin) and two outputs; thanks to the use of SSRs, these outputs function like relays and support currents of up to 3A.