Up to now, the PCAN-Router Pro from PEAK-System Technik, a 4-channel router for the CAN bus, could only be operated with the provided standard firmware and be configured through Windows software. With the now released development package, users can develop their own firmware in the C and C++ languages. The package contains several programming examples which serve as starting points for development. The library for accessing the device's resources as well as the Yagarto GNU ARM toolchain form the development environment. Using the Windows software PCAN-Flash, the completed firmware is transferred to the PCAN-Router Pro via CAN. All devices starting from serial number 100 are programmable. Customers can download the development package from the PEAK-System website for free. Together with the release of the development package for the PCAN-Router Pro, the toolchains for the PCAN-Router and PCAN-RS-232 products were also shifted to Yagarto in order to support current development standards.