cobs_device.h

#pragma once
#include <cstddef>
#include <cstdint>
#include <vector>
 
#include "vex/vex.h"
 
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;
};