C++ implementation of the SEGGER Real Time Transfer (RTT) protocol. RTT is a protocol to transfer data beetween a microcontroller and a host computer with the use of a debugger.

The implemation is fully configurable at compile time and there is no runtime overhead¹ for the initialisation of the control blocks.

For the most basic usage see examples/static_buffers.cpp.

#include "rtt/rtt.hpp"
#include <string_view>

// basic configuration with 1 up buffer in skip mode with 512 bytes size.
using RttConfig = rtt::SingleModeUpOnlyEmptyNameConfig<rtt::BufferMode::skip, 512>;
using RttType   = rtt::ControlBlock<RttConfig>;

static inline constinit typename RttType::Storage_t storage{};
static inline constinit RttType                     rttControlBlock{storage};

int main() {
    static constexpr std::string_view msg{"test\n"};
    rttControlBlock.write<0>(msg);
}

There are more advanced usecases and configurations in the examples folder.

For receiving the data on the host see segger website or openocd website.

To use this project in a cmake project, just add the rtt folder via add_subdirectory and link against it using target_link_libraries.

example:

  add_subdirectory(rtt)
  target_link_libraries(${target_name} rtt::rtt)

You can also use rtt as single header. Just copy rtt.hpp wherever you need it.

To prevent zero initializing of the storage you can place it into a ram section which does not get initialized.

example:

[[gnu::section(".noInit")]] static inline constinit typename RttType::Storage_t rttStorage;

Feel free to report bugs or submit pull requests.

• On systems with cache, the user needs to ensure that the storage and control blocks are aligned to cache lines.

• Only ranges with contigues memory are supported. There is no reason, other then performace, to not support non contigues ranges. When there is a need for that, feel free to suggest an option how to configure it.

• For Cortex-M7/M23/M33/A/R: There is a data memory barrier missing.