asb_uart.h

/*
  aSysBus UART definitions

  @copyright 2015-2017 Florian Knodt, www.adlerweb.info

  Based on iSysBus - 2010 Patrick Amrhein, www.isysbus.org

  This program is free software: you can redistribute it and/or modify
  it under the terms of the GNU General Public License as published by
  the Free Software Foundation, either version 3 of the License, or
  (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef ASB_UART__H
#define ASB_UART__H
    #include "asb.h"
    #include "Stream.h"

    /**
     * UART Communication Interface
     * @see ASB_COMM
     */
    class ASB_UART : public ASB_COMM {
        private:
            /**
             * UART reference pointer
             */
            //unsigned int _interface;
            Stream *_interface;

            /**
             * Incoming data buffer
             */
            byte _buf[35];

            /**
             * Search for next start byte and shift buffer
             * @return byte start byte found
             */
            bool bufShift();

            /**
             * Remove len bytes from the buffer
             * @return byte start byte found
             */
            bool bufShift(byte len);

        public:
            /**
             * Constructor for UART interface
             * @param Serial object used for this communication
             * @param unsigned int UART bus speed
             */
            ASB_UART(Stream &serial);

            /**
             * Initialize UART, just a dummy
             * @return byte error code, always 0/success
             */
            byte begin(void);

            /**
             * Send message to UART-bus
             * @param type 2 bit message type (ASB_PKGTYPE_*)
             * @param target address between 0x0001 and 0x07FF/0xFFFF
             * @param source source address between 0x0001 and 0x07FF
             * @param port port address between 0x00 and 0x1F, Unicast only
             * @param len number of bytes to send (0-8)
             * @param data array of bytes to send
             */
            bool asbSend(byte type, unsigned int target, unsigned int source, char port, byte len, const byte *data);

            /**
             * Receive a message from the UART-bus
             *
             * This polls the UART-Controller for new messages.
             * The received message will be passed to &pkg, if no message
             * is available the function will return false.
             *
             * @param pkg asbPacket-Reference to store received packet
             * @return true if a message was received
             */
            bool asbReceive(asbPacket &pkg);

            /**
             * Convert ASCII hex to byte
             *
             * This will convert the characters 0-9, A-F and a-f to an
             * byte-value between 0 and 15. Other inputs will return 0
             *
             * @param byte single ASCII hex character
             * @return corresponding numeric byte value
             */
            byte asbHexToByte(byte hex);
    };

#endif /* ASB_UART__H */