Files
bacnet_stack/bacnet-stack/ports/linux/rs485.c
T
2004-09-22 19:08:48 +00:00

116 lines
3.5 KiB
C

/*####COPYRIGHTBEGIN####
-------------------------------------------
Copyright (C) 2004 Steve Karg
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.
59 Temple Place - Suite 330
Boston, MA 02111-1307
USA.
As a special exception, if other files instantiate templates or
use macros or inline functions from this file, or you compile
this file and link it with other works to produce a work based
on this file, this file does not by itself cause the resulting
work to be covered by the GNU General Public License. However
the source code for this file must still be made available in
accordance with section (3) of the GNU General Public License.
This exception does not invalidate any other reasons why a work
based on this file might be covered by the GNU General Public
License.
-------------------------------------------
####COPYRIGHTEND####*/
// The module handles sending data out the RS-485 port
// and handles receiving data from the RS-485 port.
// Customize this file for your specific hardware
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdio.h>
#include "mstp.h"
// Transmits a Frame on the wire
void RS485_Send_Frame(
struct mstp_port_struct_t *mstp_port, // port to send from
uint8_t frame_type, // type of frame to send - see defines
uint8_t destination, // destination address
uint8_t source, // source address
uint8_t *data, // any data to be sent - may be null
unsigned data_len) // number of bytes of data (up to 501)
{
uint8_t buffer[INPUT_BUFFER_SIZE] = {0};
uint8_t *pbuf = NULL; // used for pointer arithmatic
unsigned len = 0; // number of bytes to send
// in order to avoid line contention
while (mstp_port->Turn_Around_Waiting)
{
// wait, yield, or whatever
}
// Disable the receiver, and enable the transmit line driver.
len = MSTP_Create_Frame(
buffer, // where frame is loaded
sizeof(buffer), // amount of space available
frame_type, // type of frame to send - see defines
destination, // destination address
source, // source address
data, // any data to be sent - may be null
data_len); // number of bytes of data (up to 501)
pbuf = &buffer[0];
while (len)
{
putc(*pbuf,stderr);
pbuf++;
len--;
}
// Wait until the final stop bit of the most significant CRC octet
// has been transmitted but not more than Tpostdrive.
// Disable the transmit line driver.
return;
}
// called by timer, interrupt(?) or other thread
void RS485_Check_UART_Data(struct mstp_port_struct_t *mstp_port)
{
if (mstp_port->ReceiveError == true)
{
// wait for state machine to clear this
}
// wait for state machine to read from the DataRegister
else if (mstp_port->DataAvailable == false)
{
// check for data
// if error,
// ReceiveError = TRUE;
// return;
mstp_port->DataRegister = 0; // FIXME: Get this data from UART or buffer
// if data is ready,
// DataAvailable = TRUE;
// return;
}
}