Fresh

A cross-interface & cross-platform mesh network with support of microcontrollers. Primarily, intended to work in small networks (not larger than about 100-200 devices).

Currently, supports:

• Broadcasts
• Unicasts
• Route discovery
• Stream fragmentation/defragmentation
• Packet retransmission
• Multi-MTU support (reshaping transit streams to lower-mtu interfaces, but not in reverse)
• Cryptographical protection against MITM/replay attacks for secure interfaces
• Combination of both secure and insecure interfaces on the same device
• Cross-platforming
• Packet duplicate avoidance
• Support for ESP-IDF v5.1.2

Needs to be done:

• Sniffing API and wireshark integration
• Removing devices and fixing routes
• Encryption (only authentication and integrity checking is implemented now)
• Proper synchronization to prevent data races

Task tracking is done via todo/fixme comments in the code.

For more details about the protocol, check mesh_protocol.h.

Usage (C++)

Including (as ESP-IDF component)

Clone a repo to your project's component directory and add fresh to REQUIRES or PRIV_REQUIRES in idf_component_register().

For more information about ESP-IDF components, check ESP-IDF Build System.

Including (as Cmake target)

Clone a repo, add to your CMakeLists.txt:

add_subdirectory(path/to/fresh)
target_link_libraries(your_target PRIVATE ${FRESH_PROJECT_NAME})

Code

#include "mesh_controller.h"
#include "interfaces/wifi_esp_now_interface.h"


void app_main() {
    // it's better to not create interfaces and controller on stack because they can take up much memory
    auto wifi_interface = new WifiEspNowMeshInterface();
    auto controller = new MeshController("network name", wifi_interface->derive_far_addr_uint32());
    
    // packet callback
    controller->user_stream_handler = [controller](MeshProto::far_addr_t src_addr, const ubyte* data, ushort size) {
        printf("Hello packet!\n");

        // sending response. builders are used to send large amount of data using many small chunks
        const char response_data[] = "hello!";
        MeshStreamBuilder builder(*controller, src_addr, sizeof(response_data));
        builder.write(response_data, sizeof(response_data));
    };
    
    // setting up mesh controller
    controller->set_psk_password("network pass"); // make sure to call this before any .add_interface()
    controller->add_interface(wifi_interface);
    
    vTaskDelay(-1);
}

Disabling build paths

You can define CMake variables to skip some build paths:

• FRESH_BUILD_SKIP_ESPIDF_COMPONENT - skip trying to initialize as ESP-IDF component
• FRESH_BUILD_SKIP_ESPIDF_STANDALONE - skip trying to initialize as standalone ESP-IDF project

Pc (Win32, Linux, etc...)

You need to install pkg-config in your build system to find dependencies such as libsodium.