skarg
120 lines
4.0 KiB
Plaintext
120 lines
4.0 KiB
Plaintext
/*####COPYRIGHTBEGIN####
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-------------------------------------------
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Copyright (C) 2004 Steve Karg
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This program is free software; you can redistribute it and/or
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modify it under the terms of the GNU General Public License
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as published by the Free Software Foundation; either version 2
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of the License, or (at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to:
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The Free Software Foundation, Inc.
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59 Temple Place - Suite 330
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Boston, MA 02111-1307
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USA.
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As a special exception, if other files instantiate templates or
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use macros or inline functions from this file, or you compile
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this file and link it with other works to produce a work based
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on this file, this file does not by itself cause the resulting
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work to be covered by the GNU General Public License. However
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the source code for this file must still be made available in
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accordance with section (3) of the GNU General Public License.
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This exception does not invalidate any other reasons why a work
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based on this file might be covered by the GNU General Public
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License.
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-------------------------------------------
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####COPYRIGHTEND####*/
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// The module handles sending data out the RS-485 port
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// and handles receiving data from the RS-485 port.
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// Customize this file for your specific hardware
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#include <stddef.h>
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#include <stdint.h>
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#include <stdbool.h>
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#include "mstp.h"
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// Transmits a Frame on the wire
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void RS485_Send_Frame(
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struct mstp_port_struct_t *mstp_port, // port to send from
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uint8_t frame_type, // type of frame to send - see defines
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uint8_t destination, // destination address
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uint8_t source, // source address
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uint8_t *data, // any data to be sent - may be null
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unsigned data_len) // number of bytes of data (up to 501)
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{
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uint8_t HeaderCRC; // used for running CRC calculation
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(void)frame_type; // FIXME: temp until we implement this code
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(void)destination; // FIXME: temp until we implement this code
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(void)source; // FIXME: temp until we implement this code
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(void)data; // FIXME: temp until we implement this code
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(void)data_len; // FIXME: temp until we implement this code
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// in order to avoid line contention
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while (mstp_port->SilenceTimer < Tturnaround)
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{
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// wait, yield, or whatever
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}
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// Disable the receiver, and enable the transmit line driver.
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// Transmit the preamble octets X'55', X'FF'.
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// As each octet is transmitted, set SilenceTimer to zero.
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HeaderCRC = 0xFF;
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// Transmit the Frame Type, Destination Address, Source Address,
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// and Data Length octets. Accumulate each octet into HeaderCRC.
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// As each octet is transmitted, set SilenceTimer to zero.
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// Transmit the ones-complement of HeaderCRC. Set SilenceTimer to zero.
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// If there are data octets, initialize DataCRC to X'FFFF'.
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// Transmit any data octets. Accumulate each octet into DataCRC.
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// As each octet is transmitted, set SilenceTimer to zero.
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// Transmit the ones-complement of DataCRC, least significant octet first.
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// As each octet is transmitted, set SilenceTimer to zero.
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// Wait until the final stop bit of the most significant CRC octet
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// has been transmitted but not more than Tpostdrive.
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// Disable the transmit line driver.
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return;
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}
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// called by timer, interrupt(?) or other thread
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void RS485_Check_UART_Data(struct mstp_port_struct_t *mstp_port)
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{
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if (mstp_port->ReceiveError == true)
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{
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// wait for state machine to clear this
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}
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// wait for state machine to read from the DataRegister
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else if (mstp_port->DataAvailable == false)
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{
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// check for data
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// if error,
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// ReceiveError = TRUE;
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// return;
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mstp_port->DataRegister = 0; // FIXME: Get this data from UART or buffer
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// if data is ready,
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// DataAvailable = TRUE;
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// return;
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}
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}
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