Modified the AT91SAM7S port and the ATmega168 port to use a slimmed down MS/TP state machine and datalink layer. Tested on AT91SAM7S-EK board.

bacnet-stack/bacdef.h

@@ -56,21 +56,14 @@
 #define BACNET_MIN_PRIORITY 1
 #define BACNET_MAX_PRIORITY 16
 
-/* embedded systems need fixed name sizes */
-#define MAX_OBJECT_NAME 10
-/* common object properties */
-typedef struct BACnet_Object_Data {
-    uint32_t Object_Identifier;
-    char Object_Name[MAX_OBJECT_NAME];
-    BACNET_OBJECT_TYPE Object_Type;
-} BACNET_OBJECT_DATA;
-
 #define BACNET_BROADCAST_NETWORK 0xFFFF
 /* IPv6 (16 octets) coupled with port number (2 octets) */
+/* note: you could be lame and only support 6 octets */
+/* FIXME: mac[] only needs to be as big as our datalink MAC */
 #define MAX_MAC_LEN 18
 struct BACnet_Device_Address {
     /* mac_len = 0 if global address */
-    int mac_len;
+    uint8_t mac_len;
     /* note: MAC for IP addresses uses 4 bytes for addr, 2 bytes for port */
     /* use de/encode_unsigned32/16 for re/storing the IP address */
     uint8_t mac[MAX_MAC_LEN];
@@ -80,7 +73,7 @@ struct BACnet_Device_Address {
     uint16_t net;               /* BACnet network number */
     /* LEN = 0 denotes broadcast MAC ADR and ADR field is absent */
     /* LEN > 0 specifies length of ADR field */
-    int len;                    /* length of MAC address */
+    uint8_t len;                    /* length of MAC address */
     uint8_t adr[MAX_MAC_LEN];   /* hwaddr (MAC) address */
 };
 typedef struct BACnet_Device_Address BACNET_ADDRESS;

bacnet-stack/ports/at91sam7s/makefile

@@ -18,10 +18,14 @@ BACNET_FLAGS += -DPRINT_ENABLED=0
 BACNET_FLAGS += -DMAX_APDU=480
 #BACNET_FLAGS += -DDLMSTP_TEST
 
-INCLUDES = -I. -I../.. -I../../demo/handler -I../../demo/object
+BACNET_ROOT = ../..
+INCLUDES = -I. 
+INCLUDES += -I$(BACNET_ROOT) 
+INCLUDES += -I$(BACNET_ROOT)/demo/handler 
+INCLUDES += -I$(BACNET_ROOT)/demo/object
 #OPTIMIZATION = -O0
 OPTIMIZATION = -Os
-CFLAGS = -fno-common $(OPTIMIZATION) $(INCLUDES) $(BACNET_FLAGS) -Wall -g
+CFLAGS = -fno-common $(INCLUDES) $(BACNET_FLAGS) -Wall -g
 LIBRARY = lib$(TARGET).a
 #  -Wa,<options> Pass comma-separated <options> on to the assembler
 AFLAGS = -Wa,-ahls,-mapcs-32,-adhlns=$(<:.s=.lst)
@@ -40,8 +44,7 @@ PORTSRC = main.c \
 	blinker.c \
 	rs485.c \
 	dlmstp.c \
-	../../crc.c \
+	$(BACNET_ROOT)/crc.c
-	../../mstp.c
 
 DEMOSRC = ai.c \
 	av.c \
@@ -50,29 +53,29 @@ DEMOSRC = ai.c \
 	h_rp.c \
 	h_wp.c \
 	device.c \
-	../../demo/handler/txbuf.c \
+	$(BACNET_ROOT)/demo/handler/txbuf.c \
-	../../demo/handler/h_whois.c \
+	$(BACNET_ROOT)/demo/handler/h_whois.c \
-	../../demo/handler/h_rd.c \
+	$(BACNET_ROOT)/demo/handler/h_rd.c \
-	../../demo/handler/h_dcc.c
+	$(BACNET_ROOT)/demo/handler/h_dcc.c
 
-CORESRC = ../../npdu.c \
+CORESRC = $(BACNET_ROOT)/npdu.c \
-	../../bacint.c \
+	$(BACNET_ROOT)/bacint.c \
-	../../apdu.c \
+	$(BACNET_ROOT)/apdu.c \
-	../../bacdcode.c \
+	$(BACNET_ROOT)/bacdcode.c \
-	../../bacaddr.c \
+	$(BACNET_ROOT)/bacaddr.c \
-	../../bacstr.c \
+	$(BACNET_ROOT)/bacstr.c \
-	../../abort.c \
+	$(BACNET_ROOT)/abort.c \
-	../../bacerror.c \
+	$(BACNET_ROOT)/bacerror.c \
-	../../reject.c \
+	$(BACNET_ROOT)/reject.c \
-	../../bacapp.c \
+	$(BACNET_ROOT)/bacapp.c \
-	../../datetime.c \
+	$(BACNET_ROOT)/datetime.c \
-	../../rp.c \
+	$(BACNET_ROOT)/rp.c \
-	../../wp.c \
+	$(BACNET_ROOT)/wp.c \
-	../../dcc.c \
+	$(BACNET_ROOT)/dcc.c \
-	../../rd.c \
+	$(BACNET_ROOT)/rd.c \
-	../../whois.c \
+	$(BACNET_ROOT)/whois.c \
-	../../iam.c \
+	$(BACNET_ROOT)/iam.c \
-	../../version.c
+	$(BACNET_ROOT)/version.c
 
 CSRC = $(PORTSRC) $(DEMOSRC)
 #CSRC = $(PORTSRC)
@@ -96,8 +99,21 @@ lib: $(LIBRARY)
 $(LIBRARY): $(COREOBJ) Makefile
 	$(AR) rcs $@ $(COREOBJ)
 
+# allow a single file to be unoptimized for debugging purposes
+#dlmstp.o:
+#	$(CC) -c $(CFLAGS) $*.c -o $@
+#
+#main.o:
+#	$(CC) -c $(CFLAGS) $*.c -o $@
+#
+#$(BACNET_ROOT)/npdu.o:
+#	$(CC) -c $(CFLAGS) $*.c -o $@
+#
+#$(BACNET_ROOT)/apdu.o:
+#	$(CC) -c $(CFLAGS) $*.c -o $@
+
 .c.o:
-	$(CC) -c $(CFLAGS) $*.c -o $@
+	$(CC) -c $(OPTIMIZATION) $(CFLAGS) $*.c -o $@
 
 .s.o:
 	$(CC) -c $(AFLAGS) $*.s -o $@

bacnet-stack/ports/at91sam7s/rs485.c

@@ -32,7 +32,6 @@
 #include <stdbool.h>
 #include <stdlib.h>
 #include <stdio.h>
-#include "mstp.h"
 #include "timer.h"
 
 /* This file has been customized for use with UART0
@@ -44,16 +43,17 @@ static volatile AT91S_USART *RS485_Interface = AT91C_BASE_US0;
 /* baud rate */
 static int RS485_Baud = 38400;
 
-/****************************************************************************
+/* The minimum time after the end of the stop bit of the final octet of a */
-* DESCRIPTION: Sets the interface - UART0 or UART1 or...
+/* received frame before a node may enable its EIA-485 driver: 40 bit times. */
-* RETURN:      none
+/* At 9600 baud, 40 bit times would be about 4.166 milliseconds */
-* ALGORITHM:   none
+/* At 19200 baud, 40 bit times would be about 2.083 milliseconds */
-* NOTES:       none
+/* At 38400 baud, 40 bit times would be about 1.041 milliseconds */
-*****************************************************************************/
+/* At 57600 baud, 40 bit times would be about 0.694 milliseconds */
-void RS485_Set_Interface(char *ifname)
+/* At 76800 baud, 40 bit times would be about 0.520 milliseconds */
-{
+/* At 115200 baud, 40 bit times would be about 0.347 milliseconds */
-    RS485_Interface = (volatile AT91S_USART *)ifname;
+/* 40 bits is 4 octets including a start and stop bit with each octet */
-}
+#define Tturnaround  (40UL)
+/* turnaround_time_milliseconds = (Tturnaround*1000UL)/RS485_Baud; */
 
 /****************************************************************************
 * DESCRIPTION: Initializes the RS485 hardware and variables, and starts in
@@ -152,27 +152,51 @@ bool RS485_Set_Baud_Rate(uint32_t baud)
     return valid;
 }
 
-/* Transmits a Frame on the wire */
+/****************************************************************************
-void RS485_Send_Frame(
+* DESCRIPTION: Waits on the SilenceTimer for 40 bits.
-    volatile struct mstp_port_struct_t *mstp_port, /* port specific data */
+* RETURN:      none
-    uint8_t * buffer,  /* frame to send (up to 501 bytes of data) */
+* ALGORITHM:   none
-    uint16_t nbytes)   /* number of bytes of data (up to 501) */
+* NOTES:       none
+*****************************************************************************/
+void RS485_Turnaround_Delay(void)
 {
-    uint8_t turnaround_time;
+    uint16_t turnaround_time;
+    
+    /* delay after reception before trasmitting - per MS/TP spec */
+    /* wait a minimum  40 bit times since reception */
+    /* at least 1 ms for errors: rounding, clock tick */
+    turnaround_time = 1 + ((Tturnaround*1000UL)/RS485_Baud);
+    while (Timer_Silence() < turnaround_time) {
+        /* do nothing - wait for timer to increment */
+    };
+}
 
-    /* delay after reception - per MS/TP spec */
+/****************************************************************************
-    if (mstp_port) {
+* DESCRIPTION: Enable or disable the transmitter
-        /* wait a minimum 40 bit times since reception */
+* RETURN:      none
-        /* at least 1 ms for errors: rounding, clock tick */
+* ALGORITHM:   none
-        turnaround_time = 1 + ((Tturnaround*1000)/RS485_Baud);
+* NOTES:       The Atmel ARM7 has an automatic enable/disable in RS485 mode.
-        while (mstp_port->SilenceTimer() < turnaround_time) {
+*****************************************************************************/
-            /* do nothing - wait for timer to increment */
+void RS485_Transmitter_Enable(bool enable)
-        };
+{
-    }
+    (void)enable;
-    /* toggle LED on send */
+}
+
+/****************************************************************************
+* DESCRIPTION: Send some data and wait until it is sent
+* RETURN:      none
+* ALGORITHM:   none
+* NOTES:       none
+*****************************************************************************/
+void RS485_Send_Data(
+    uint8_t * buffer,       /* data to send */
+    uint16_t nbytes)       /* number of bytes of data */
+{
+    /* LED on send */
     volatile AT91PS_PIO pPIO = AT91C_BASE_PIOA;
     /* LED ON */
     pPIO->PIO_CODR = LED1;
+    /* send all the bytes */
     while (nbytes) {
         while (!(RS485_Interface->US_CSR & AT91C_US_TXRDY)) {
             /* do nothing - wait until Tx buffer is empty */
@@ -180,60 +204,78 @@ void RS485_Send_Frame(
         RS485_Interface->US_THR = *buffer;
         buffer++;
         nbytes--;
-        /* per MSTP spec */
-        if (mstp_port) {
-            mstp_port->SilenceTimerReset();
-        }
     }
     while (!(RS485_Interface->US_CSR & AT91C_US_TXRDY)) {
         /* do nothing - wait until Tx buffer is empty */
     }
-
+    /* per MSTP spec */
-    return;
+    Timer_Silence_Reset();
 }
 
-/* called by timer, interrupt(?) or other thread */
+/****************************************************************************
-void RS485_Check_UART_Data(struct mstp_port_struct_t *mstp_port)
+* DESCRIPTION: Return true if a framing or overrun error is present
+* RETURN:      true if error
+* ALGORITHM:   none
+* NOTES:       Clears any error flags.
+*****************************************************************************/
+bool RS485_ReceiveError(void)
 {
+    bool ReceiveError = false;
+    /* LED on send */
     volatile AT91PS_PIO pPIO = AT91C_BASE_PIOA;
 
-    if (mstp_port->ReceiveError == true) {
+    /* check for data or error */
-        /* wait for state machine to clear this */
+    if (RS485_Interface->US_CSR & (AT91C_US_OVRE | AT91C_US_FRAME)) {
-    } else if (mstp_port->DataAvailable == false) {
+        /* clear the error flag */
-        /* check for data or error */
+        RS485_Interface->US_CR = AT91C_US_RSTSTA;
-        if (RS485_Interface->US_CSR & (AT91C_US_OVRE | AT91C_US_FRAME)) {
+        ReceiveError = true;
-            /* clear the error flag */
+        /* LED ON */
-            RS485_Interface->US_CR = AT91C_US_RSTSTA;
+        pPIO->PIO_CODR = LED2;
-            mstp_port->ReceiveError = true;
-            /* LED ON */
-            pPIO->PIO_CODR = LED2;
-        } else if ( RS485_Interface->US_CSR & AT91C_US_RXRDY) {
-            /* data is available */
-            mstp_port->DataRegister = RS485_Interface->US_RHR;
-            mstp_port->DataAvailable = true;
-            /* LED ON */
-            pPIO->PIO_CODR = LED2;
-        }
     }
+
+    return ReceiveError;
+}
+
+/****************************************************************************
+* DESCRIPTION: Return true if data is available 
+* RETURN:      true if data is available, with the data in the parameter set
+* ALGORITHM:   none
+* NOTES:       none
+*****************************************************************************/
+bool RS485_DataAvailable(uint8_t *DataRegister)
+{
+    bool DataAvailable = false;
+    /* LED on send */
+    volatile AT91PS_PIO pPIO = AT91C_BASE_PIOA;
+    
+    if ( RS485_Interface->US_CSR & AT91C_US_RXRDY) {
+        /* data is available */
+        *DataRegister = RS485_Interface->US_RHR;
+        DataAvailable = true;
+        /* LED ON */
+        pPIO->PIO_CODR = LED2;
+    }
+    
+    return DataAvailable;
 }
 
 #ifdef TEST_RS485
-static struct mstp_port_struct_t MSTP_Port;
-
 int main(void)
 {
     unsigned i = 0;
+    uint8_t DataRegister;
 
     RS485_Set_Baud_Rate(38400);
     RS485_Initialize();
     /* receive task */
     for (;;) {
-        RS485_Check_UART_Data(&MSTP_Port);
+        if (RS485_DataAvailable(&DataRegister)) {
-        if (MSTP_Port.DataAvailable) {
+            fprintf(stderr,"%02X ",DataRegister);
-                fprintf(stderr,"%02X ",MSTP_Port.DataRegister);
+        } else if (RS485_ReceiveError()) {
-                MSTP_Port.DataAvailable = false;
+            fprintf(stderr,"ERROR ");
         }
+
     }
 }
-#endif                          /* TEST_ABORT */
+#endif 
 

bacnet-stack/ports/at91sam7s/rs485.h

@@ -27,24 +27,24 @@
 #define RS485_H
 
 #include <stdint.h>
-#include "mstp.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif                          /* __cplusplus */
 
-    void RS485_Set_Interface(char *ifname);
-
     void RS485_Initialize(void);
 
-    void RS485_Send_Frame(
+    void RS485_Transmitter_Enable(bool enable);
-        volatile struct mstp_port_struct_t *mstp_port, /* port specific data */
-        uint8_t * buffer,  /* frame to send (up to 501 bytes of data) */
-        uint16_t nbytes);  /* number of bytes of data (up to 501) */
 
-    uint8_t RS485_Check_UART_Data(
+    /* NOTE: Only able to send up to 255 bytes at a time */
-        volatile struct mstp_port_struct_t *mstp_port); /* port specific data */
+    void RS485_Send_Data(
+        uint8_t * buffer,       /* data to send */
+        uint16_t nbytes);       /* number of bytes of data */
 
+    bool RS485_ReceiveError(void);
+    bool RS485_DataAvailable(uint8_t *data);
+
+    void RS485_Turnaround_Delay(void);
     uint32_t RS485_Get_Baud_Rate(void);
     bool RS485_Set_Baud_Rate(uint32_t baud);
 

bacnet-stack/ports/at91sam7s/timer.c

@@ -48,7 +48,7 @@
 /* global variable counts interrupts */
 volatile unsigned long Timer_Milliseconds;
 /* MS/TP Silence Timer */
-static volatile uint16_t SilenceTime;
+static volatile int SilenceTime;
 
 static void Timer0_Setup(int milliseconds) {
     //        TC Block Control Register TC_BCR    (read/write)
@@ -306,11 +306,11 @@ static void Timer0IrqHandler (void) {
     dummy = pTC->TC_SR;
     // increment the tick count
     Timer_Milliseconds++;
-    if (SilenceTime < 0xFFFF)
+    if (SilenceTime < 60000)
         SilenceTime++;
 }
 
-uint16_t Timer_Silence(void)
+int Timer_Silence(void)
 {
     return SilenceTime;
 }

bacnet-stack/ports/at91sam7s/timer.h

@@ -35,7 +35,7 @@ extern "C" {
 #endif                          /* __cplusplus */
 
     void TimerInit(void);
-    uint16_t Timer_Silence(void);
+    int Timer_Silence(void);
     void Timer_Silence_Reset(void);
 
 #ifdef __cplusplus

bacnet-stack/ports/atmega168/dlmstp.c

@@ -441,7 +441,6 @@ static void MSTP_Send_Frame(
         RS485_Send_Data(buffer, 2);
     }
     RS485_Transmitter_Enable(false);
-    Timer_Silence_Reset();
 }
 
 static void MSTP_Receive_Frame_FSM(void)
@@ -1243,6 +1242,9 @@ uint16_t dlmstp_receive(
     if (MSTP_Flag.ReceivePacketPending) {
         MSTP_Flag.ReceivePacketPending = false;
         pdu_len = DataLength;
+        src->mac_len = 1;
+        src->mac[0] = SourceAddress;
+        /* data is already in the pdu pointer */
     }
 
     return pdu_len;

bacnet-stack/ports/atmega168/rs485.c

@@ -180,6 +180,8 @@ void RS485_Send_Data(
         /* do nothing - wait until the entire frame in the 
            Transmit Shift Register has been shifted out */
     }
+    /* per MSTP spec */
+    Timer_Silence_Reset();
 }
 
 
@@ -191,25 +193,25 @@ void RS485_Send_Data(
 *****************************************************************************/
 bool RS485_ReceiveError(void)
 {
-    bool uart_error = false;
+    bool ReceiveError = false;
     uint8_t dummy_data;
 
     /* check for framing error */
     if (BIT_CHECK(UCSR0A,FE0)) {
-        uart_error = true;
+        ReceiveError = true;
     }
     /* check for overrun error */
     if (BIT_CHECK(UCSR0A,DOR0)) {
-        uart_error = true;
+        ReceiveError = true;
     }
     /* flush the receive buffer */
-    if (uart_error) {
+    if (ReceiveError) {
         while (BIT_CHECK(UCSR0A,RXC0)) {
             dummy_data = UDR0;
         }
     }
     
-    return uart_error;
+    return ReceiveError;
 }
 
 /****************************************************************************
@@ -230,3 +232,24 @@ bool RS485_DataAvailable(uint8_t *data)
     
     return uart_data;
 }
+
+#ifdef TEST_RS485
+int main(void)
+{
+    unsigned i = 0;
+    uint8_t DataRegister;
+
+    RS485_Set_Baud_Rate(38400);
+    RS485_Initialize();
+    /* receive task */
+    for (;;) {
+        if (RS485_DataAvailable(&DataRegister)) {
+            fprintf(stderr,"%02X ",DataRegister);
+        } else if (RS485_ReceiveError()) {
+            fprintf(stderr,"ERROR ");
+        }
+
+    }
+}
+#endif                          /* TEST_ABORT */
+

bacnet-stack/tsm.c

@@ -35,7 +35,6 @@
 #include <stdbool.h>
 #include <stdint.h>
 #include <stddef.h>
-#include <string.h>             /* memmove() */
 #include "bits.h"
 #include "apdu.h"
 #include "bacdef.h"