Diff: ait_link.h

Revision:

0:8e8dfc870cb2

Child:

3:bfc4928cd279

diff -r 000000000000 -r 8e8dfc870cb2 ait_link.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ait_link.h	Mon Apr 04 11:19:55 2016 +0000
@@ -0,0 +1,75 @@
+// Adapted by Benjamin Hepp from ArduHDLC library
+
+/*
+Arduhdlc is Arduino HDLC library, which can be used over any interface.
+Copyright (C) 2015 Jarkko Hautakorpi et al. see LICENSE.txt
+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 2
+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, write to the Free Software
+Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+*/
+
+
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <stddef.h>
+
+namespace ait {
+
+  class AITLink {
+  public:
+    /* HDLC Asynchronous framing */
+    /* The frame boundary octet is 01111110, (7E in hexadecimal notation) */
+    const static uint8_t FRAME_BOUNDARY_OCTET = 0x7E;
+
+    /* A "control escape octet", has the bit sequence '01111101', (7D hexadecimal) */
+    const static uint8_t CONTROL_ESCAPE_OCTET = 0x7D;
+
+    /* If either of these two octets appears in the transmitted data, an escape octet is sent, */
+    /* followed by the original data octet with bit 5 inverted */
+    const static uint8_t INVERT_OCTET = 0x20;
+
+    /* The frame check sequence (FCS) is a 16-bit CRC-CCITT */
+    /* AVR Libc CRC function is _crc_ccitt_update() */
+    /* Corresponding CRC function in Qt (www.qt.io) is qChecksum() */
+    const static uint16_t CRC16_CCITT_INIT_VAL = 0xFFFF;
+
+    AITLink(size_t max_frame_length = 1024);
+    virtual ~AITLink();
+
+    bool sendFrame(const uint8_t* frame_buffer, size_t frame_length);
+    void inputReceivedChar(uint8_t data);
+
+    /* User must define a function, that will process the valid received frame */
+    /* This function can act like a command router/dispatcher */
+    void registerFrameHandler(void (*callback)(void* user_data, const uint8_t* frame_buffer, size_t frame_length), void* user_data);
+
+  protected:
+    virtual void handleFrame(const uint8_t* frame_buffer, size_t frame_length);
+    /* User must define a function to send a byte throug USART, I2C, SPI etc.*/
+    virtual void sendChar(uint8_t data) = 0;
+
+  private:
+    uint16_t crcCcittUpdate(uint16_t crc, uint8_t data);
+
+    bool escape_character;
+    size_t frame_position;
+    // 16bit CRC sum for crcCcittUpdate
+    uint16_t frame_checksum;
+    size_t max_frame_length;
+    uint8_t* receive_frame_buffer;
+    void (*handle_frame_callback)(void* user_data, const uint8_t* frame_buffer, size_t frame_length);
+    void* callback_user_data;
+  };
+
+}
+