cobs_device.h

#pragma once
#include "vex.h"
 
#include <cstddef>
#include <cstdint>
#include <vector>
 
class COBSSerialDevice {
  public:
    // Decoded packet containing the data one wishes to send
    using Packet = std::vector<uint8_t>;
    // Cobs Encoded packet containing 0 delimeters ready to be sent over the wire
    using WirePacket = std::vector<uint8_t>;

    COBSSerialDevice(int32_t port, int32_t baud);
    int send_cobs_packet_blocking(const uint8_t *data, size_t size, bool leading_delimeter = false);
    int receive_cobs_packet_blocking(uint8_t *buffer, size_t max_size, uint32_t timeout_us = 0);

    static void cobs_encode(const Packet &in, WirePacket &out, bool add_start_delimeter = false);
    static void cobs_decode(const WirePacket &in, Packet &out);
    static void hexdump(const uint8_t *data, size_t len);
 
    Packet get_last_decoded_packet();
 
  protected:
    bool poll_incoming_data_once();

    bool handle_incoming_byte(uint8_t byte);
 
  private:
    vex::mutex serial_access_mut;
    int32_t port;
    int32_t baud;
 
    // Buffer to hold data about to be written
    Packet writing_buffer;
    // Buffer to hold encoded cobs data about to be written
    WirePacket encoded_write;
 
    // buffer used to get data from VEX OS land to userland. Scratch space
    std::vector<uint8_t> incoming_buffer;
    // buffer to read bytes in when building up a cobs packet
    WirePacket incoming_wire_packet;
    // contains the last packet that was received and decoded
    Packet last_decoded_packet;
};