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edhaslam
Joined: 15 Jul 2005
Posts: 89
Location: UK
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| Unidentified Identifier: RS232_ERRORS |
 Posted: Fri Jan 13, 2006 7:50 am |
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Hi all,
I've progressed onto learning about serial interupts and circular buffers and found a piece of code that checks the framing error bit of the rs232_error register, but when I compile the code I get the 'Unidentified Identifier' error message. The first part of the interupt routine is as follows:
| Code: |
#int_rda
void SerialInterrupt ( void )
char cChar;
if ( RS232_ERRORS & 0x04 ) // get framing error bit from Rx status reg
{
cRxErrorFlag = ON;
}
cChar = getchar(); // get char from UART, clear any errors
etc...
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Do I have to define/declare the use of the RS232_ERRORS register somewhere at the beginning of the code? Can someone point me to any information on how to access/use this register? |
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dyeatman
Joined: 06 Sep 2003
Posts: 1937
Location: Norman, OK
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| Posted: Fri Jan 13, 2006 10:31 am |
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This has been discussed numerous times on this forum. I appreciate that you are trying to learn but please try searching the forum before asking a question to see if it has already been answered. Many times you will get much more information and example code as a bonus!
Take a look at the link below for your answer..
http://www.ccsinfo.com/forum/viewtopic.php?t=22876&highlight=rs232errors
Regards |
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edhaslam
Joined: 15 Jul 2005
Posts: 89
Location: UK
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| Posted: Fri Jan 13, 2006 1:25 pm |
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| dyeatman wrote: | This has been discussed numerous times on this forum. I appreciate that you are trying to learn but please try searching the forum before asking a question to see if it has already been answered. Many times you will get much more information and example code as a bonus!
Take a look at the link below for your answer..
http://www.ccsinfo.com/forum/viewtopic.php?t=22876&highlight=rs232errors
Regards |
Believe me I have searched and searched and I never post until I am really stuck. I have been programming for some time now and am not a newbie, just new to this particular area.
I know this has been discussed many times before and I have read *both* of the threads that you have suggested prior to posting, but it still hasn't answered my question. All of the suggestions that have been offered in those threads haven't helped me.
Can you (or anyone else) point me to where the RS232_ERRORS is discussed in the manual or some other source?
BTW: I am using the latest version of the compiler. I can post the entire code if necessary. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Jan 13, 2006 2:02 pm |
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Are you using #case with RS232_ERRORS in upper case ?
That will cause the "undefined identifier error, because CCS
uses lower case for that symbol. See the symbol table below:
| Code: |
SYMBOL TABLE
LABEL VALUE
PSP_DATA 00000008
CCP_1_LOW 00000015
CCP_1 00000015
CCP_1_HIGH 00000016
CCP_2_LOW 0000001B
CCP_2 0000001B
CCP_2_HIGH 0000001C
rs232_errors 00000020
main.c 00000021
_RETURN_ 00000078
main 00000004 |
| Quote: |
#include <16F877.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
#case // This will cause the "undefined identifier" error
//============================
void main()
{
char c;
c = RS232_ERRORS;
while(1);
} |
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Fri Jan 13, 2006 2:59 pm |
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| Quote: |
Can you (or anyone else) point me to where the RS232_ERRORS is discussed in the manual or some other source?
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Well, this is not the only issue that is not clearly discussed in the manual nor in any source.
CCS Compiler has a lot of built-in functions whose generated object code is not visible to
the user.
Anyway I will try to clarify this issue. When you include the parameter ERRORS in the
pre-processor directive #use RS232(..) the compiler generate extra code to clear the
detected errors in the RCSTA register. The capability of detecting an error is a PIC feature,
not a compiler capability.
PIC microcontrollers with built in Serial Controller Interface has this feature
because its data recovery block operate at 16x times the baud rate so it can recover
enough info to detect unexpected levels detected in every single bit of the arraiving
character, namelly overrun errors.
Normally this is done in the ninth bit (normally the STOP bit for an 8 bit wide) the
compiler make a copy of the RCSTA (Receiver Status and Control Register)
in the variable rs232_errors and test the bit 1 (OERR) to determine if any error
occurred during the char reception, if any error occurred, set the enable bit CREN.
The action of the CREN bit is not trivial:
CREN: Continuous Receive Enable bit.
1= Enable continuous receive
0= Disable continuous receive
If you do not include the ERRORS parameter in the #use RS232(..) directive,
the ocurrence of the first error will clear the CREN and block the receiver.
Including ERRORS the compiler generate this extra code to handle the detected errors.
| Code: |
D <! .................... #use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8,errors)
D <! 00A0: BTFSS PIR1.5
D <! 00A2: BRA 00A0
D <! 00A4: MOVFF RCSTA,rs232_errors
D <! 00A8: MOVFF RCREG,01
D <! 00AC: BTFSS rs232_errors.1
D <! 00AE: BRA 00B4
D <! 00B0: BCF RCSTA.4
D <! 00B2: BSF RCSTA.4
D <! 00B4: NOP
D <! 00B6: GOTO 00BC (RETURN)
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Humberto |
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Ttelmah
Guest
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| Posted: Fri Jan 13, 2006 3:55 pm |
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Generally, CREN, is not cleared by an error.
The error flags themselves 'block' reception, and it is the act of clearing CREN, that clears the errors. Hence the bit has to be cleared, and then reset.
It may just be 'worth' being aware of this difference, if handling any of this yourself.
Best Wishes |
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edhaslam
Joined: 15 Jul 2005
Posts: 89
Location: UK
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| Posted: Sat Jan 14, 2006 10:47 am |
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Hi Guys,
This is all very useful, constructive information, just what I needed - many thanks.
I haven't tried using the #case pre-processor yet but I am using ERRORS in #use rs-232. I did try rs232_errors in uppper and lower case but no difference there.
Here is the piece of code that I have been learning from. It's for a GPS compass. Unfortunately I can't remember who wrote it, so I can't credit them. They did publish it on the web for people to use, so I feel it's ok to post the whole thing here. If you do recognise the code, then an eplanation of the use of the rs232_errors variable in the code would be very useful (or anyone else who can comment on it!).
| Code: |
/****************************************************************************
compass.c
This program receives NMEA-0183 heading data from a GPS
and displays it on an array of LEDs.
+5
|
14
----------
| |-6----- N
~SerIn --7-| |-9----- NE
| |-10---- E
XTAL-15-| 16F628 |-11---- SE
XTAL-16-| |-2----- S
CLK -12-| |-1----- SW
DATA -13-| |-18---- W
MCLR --4-| |-17---- NW
----------
5
| CLK, DATA, MCLR are optional programming port.
Gnd
***************************************************************************/
#case
#include <16F628.h>
#include <jonsinc.h>
#define EOF 0x00
#define COMMA ','
#define CR 13
#define SPACE ' '
#define PERIOD '.'
#define DOLLAR '$'
#define NULL 0
#define GPRMC_CODE 75
#define RX_BUFFER_SIZE 70
#define LED_N PIN_B0
#define LED_NE PIN_B3
#define LED_E PIN_B4
#define LED_SE PIN_B5
#define LED_S PIN_A3
#define LED_SW PIN_A2
#define LED_W PIN_A1
#define LED_NW PIN_A0
#define ROTATE_MS 30
#define RX_IN PIN_B1
#define PROG_CLK PIN_B6
#define PROG_DAT PIN_B6
#define PROG_MCLR PIN_A5
#separate char GetField ( void );
#separate void AllOff ( void );
#separate void GetHeading ( void );
#separate void DisplayHeading ( void );
#separate long TrueToMag ( long iH );
#separate long FieldFiveToLong ( void );
#separate void InitRxBuffer ( char cCode );
#separate char GetRxChar ( void );
#fuses HS, NOPROTECT, PUT, NOWDT, BROWNOUT, NOLVP, NOCPD, NOMCLR
#use standard_io ( A )
#use standard_io ( B )
#use delay ( clock = 8000000 )
#use rs232 ( baud=4800, xmit=PIN_B2, rcv=PIN_B1, ERRORS ) // XMIT must be assigned to enable hardward USART
static char cC [ 10 ]; // local buffer
static char cTimeOut;
static char cRxBuffer [ RX_BUFFER_SIZE ]; // Fifo
static char cRxByteCnt; // Number of bytes in the recv fifo
static char *cRxBufferWritePtr; // Pointers for the Rx buffer
static char *cRxBufferReadPtr;
static char cRxIsrState, cRxMsgTypeReceived, cRxMsgTypeDesired;
static char cRxMsgReady, cReceiveFlag;
static long iVar, iHdg;
static char cRxErrorFlag, cVarDir, cError;
/*******************************************************************/
#int_rtcc
void Timer0Interrupt ( void )
{
// Gets here every 16.52mS
// Handles data timeout
if ( cTimeOut != 0 )
{
cTimeOut--;
}
}
#int_rda
void SerialInterrupt ( void )
{
/*
Reads incoming data from the USART and puts in in a rolling buffer
( but in this application, it should never roll.)
If the buffer is full, this routine just discards the received byte.
Not checking the LRC byte at the end of the NMEA-0183 sentence.
*/
char cChar;
if ( rs232_errors & 0x04 ) // get framing error bit from Rx status reg
{
cRxErrorFlag = ON;
}
cChar = getchar(); // get char from UART, clear any errors
if ( cRxByteCnt == RX_BUFFER_SIZE ) // is recv fifo full ???
{
goto done;
}
switch ( cRxIsrState )
{
case 0:
{
if ( cChar == DOLLAR ) // if start of NMEA0183 message
{
cRxByteCnt = 0; // reset byte count
cReceiveFlag = OFF; // default to off
cRxMsgTypeReceived = NULL; // set hashed value to null
cRxIsrState++; // next state
}
break;
}
case 1: // five type characters to obtain
case 2:
case 3:
case 4:
case 5:
{
cRxMsgTypeReceived ^= cChar; // hash in msg type
if ( cRxIsrState++ == 5 ) // if time to check message type
{
if ( cRxMsgTypeReceived == cRxMsgTypeDesired ) // if good
{
cReceiveFlag = YES; // enable receiving
cRxBufferWritePtr = cRxBuffer; // reset to beginning of buffer
}
else // don't want this message
{
cRxIsrState = 0; // reset to look for next msg
}
}
break;
}
case 6:
{
/* Case 6 skips the comma character following msg type */
cRxIsrState++;
break;
}
default: // remainder of characters
{
if ( cReceiveFlag == YES ) // if this message is wanted
{
*cRxBufferWritePtr = cChar; // put char in fifo
cRxBufferWritePtr++; // increment pointer
if ( cRxBufferWritePtr == ( cRxBuffer + RX_BUFFER_SIZE ) ) // pointer past end ?
{
cRxBufferWritePtr = cRxBuffer; // set pointer to start of fifo
}
cRxByteCnt++; // Increment byte count
if ( cChar == CR )
{
cRxMsgReady = YES; // signal that message is ready
cReceiveFlag = NO; // no more receive
}
}
}
}
done:; // label
}
/*******************************************************************/
void main ( void )
{
char cX;
/* INITIALIZE */
output_float ( RX_IN ); // ensure Rx input is HiZ
output_float ( PROG_CLK );
output_float ( PROG_DAT );
output_float ( PROG_MCLR );
// SETUP TIMER 0
// Need 8-bit Timer0 to roll over every 13mS, approximately.
// Roll time = 256 * 1 / ( clock_freq / prescaler setting / 4 )
setup_counters ( RTCC_INTERNAL, RTCC_DIV_128 ); // ~13mS timer wrap
/* INTERRUPTS */
enable_interrupts ( INT_TIMER1 ); // enable Timer1 interrupt
enable_interrupts ( INT_RTCC ); // enable Timer0 interrupt
enable_interrupts ( INT_RDA ); // enable serial interrupt
enable_interrupts ( GLOBAL ); // enable all interrupts
/* VARIABLES */
iVar = NULL; // default, no variation yet
cVarDir = SPACE; // default, no variation yet
cRxErrorFlag = OFF;
for ( cX = 0; cX < 5; cX++ )
{
output_low ( LED_NW ); output_high ( LED_N ); delay_ms ( ROTATE_MS );
output_low ( LED_N ); output_high ( LED_NE ); delay_ms ( ROTATE_MS );
output_low ( LED_NE ); output_high ( LED_E ); delay_ms ( ROTATE_MS );
output_low ( LED_E ); output_high ( LED_SE ); delay_ms ( ROTATE_MS );
output_low ( LED_SE ); output_high ( LED_S ); delay_ms ( ROTATE_MS );
output_low ( LED_S ); output_high ( LED_SW ); delay_ms ( ROTATE_MS );
output_low ( LED_SW ); output_high ( LED_W ); delay_ms ( ROTATE_MS );
output_low ( LED_W ); output_high ( LED_NW ); delay_ms ( ROTATE_MS );
}
output_low ( LED_NW );
/* MAIN LOOP */
while ( TRUE )
{
cTimeOut = 242; // 242 * 0.0165mS = 4 seconds
cRxErrorFlag = OFF; // default to off
cError = OFF;
InitRxBuffer( GPRMC_CODE ); // set code and turn on serial interrupt
while ( ( cRxMsgReady == NO ) && ( cTimeOut != 0 ) ); // wait for RMC sentence
//disable_interrupts ( INT_RDA ); // ignore rest of messages
if ( ( cTimeOut != 0 ) && ( cRxErrorFlag == OFF ) ) // if no errors
{
GetHeading(); // get heading and variation
AllOff(); // turn all LED's off
if ( cError == OFF )
{
DisplayHeading(); // display heading
}
}
else
{
AllOff(); // error, data timeout or framing error
}
//enable_interrupts ( INT_RDA ); // enable Rx again
}
}
/******************************************************************/
#separate void GetHeading ( void )
{
GetField(); // skip UTC
GetField(); // A = OK, V = warning
if ( cC [ 0 ] == 'A' ) // if valid
{
GetField(); // skip LAT
GetField(); // skip N/S
GetField(); // skip LON
GetField(); // skip E/W
GetField(); // skip SPD
GetField(); // get HDG
iHdg = FieldFiveToLong(); // convert
GetField(); // skip FIX DATE
GetField(); // get MAG VAR
iVar = FieldFiveToLong(); // convert
GetField(); // get EW variation direction
cVarDir = cC [ 0 ]; // save variation direction
iHdg = TrueToMag ( iHdg ); // factor variation into heading
}
else
{
cError = ON; // error, corrupted data from satellite
}
}
#separate void AllOff ( void )
{
output_low ( LED_N );
output_low ( LED_NE );
output_low ( LED_E );
output_low ( LED_SE );
output_low ( LED_S );
output_low ( LED_SW );
output_low ( LED_W );
output_low ( LED_NW );
}
#separate void DisplayHeading ( void )
{
if ( ( ( iHdg > 337 ) && ( iHdg <= 359 ) ) || ( ( iHdg >= 0 ) && ( iHdg <= 23 ) ) ) // N
{
output_high ( LED_N );
}
if ( ( iHdg > 23 ) && ( iHdg <= 68 ) ) // NE
{
output_high ( LED_NE );
}
if ( ( iHdg > 68 ) && ( iHdg <= 113 ) ) // E
{
output_high ( LED_E );
}
if ( ( iHdg > 113 ) && ( iHdg <= 158 ) ) // SE
{
output_high ( LED_SE );
}
if ( ( iHdg > 158 ) && ( iHdg <= 203 ) ) // S
{
output_high ( LED_S );
}
if ( ( iHdg > 203 ) && ( iHdg <= 248 ) ) // SW
{
output_high ( LED_SW );
}
if ( ( iHdg > 248 ) && ( iHdg <= 293 ) ) // W
{
output_high ( LED_W );
}
if ( ( iHdg > 293 ) && ( iHdg <= 337 ) ) // NW
{
output_high ( LED_NW );
}
}
#separate long FieldFiveToLong ( void )
{
/* Converts ABC.D to long ABC, rounds fraction part up or down */
long iX;
iX = 100 * ( long ) ( cC [ 0 ] - 0x30 );
iX += 10 * ( long ) ( cC [ 1 ] - 0x30 );
iX += ( long ) ( cC [ 2 ] - 0x30 );
if ( ( cC [ 3 ] == PERIOD ) && ( cC [ 4 ] >= '5' ) )
{
iX++; // round up
}
return ( iX );
}
#separate long TrueToMag ( long iH )
{
/* Magnetic variation information comes from the RMC sentence */
if ( cVarDir == 'W' )
{
iH += iVar;
}
else
{
if ( iH >= iVar )
{
iH -= iVar; // OK as-is
}
else
{
iH = iH + 360 - iVar; // correct for below zero
}
}
if ( iH >= 360 )
{
iH -= 360;
}
return ( iH );
}
#separate char GetField ( void )
{
char cX, cIndex;
// Get next field from cRxBuffer and put in cC buffer.
cX = NULL;
cIndex = 0;
while ( cTimeOut != 0 )
{
cX = GetRxChar();
if ( ( cX == COMMA ) || ( cX == CR ) )
{
break;
}
cC [ cIndex++ ] = cX;
}
cC [ cIndex ] = EOF;
return ( cIndex ); // return number of characters in field
}
/* RS232 FUNCTIONS ================================================== */
#separate void InitRxBuffer ( char cCode )
{
disable_interrupts ( INT_RDA );
cRxBufferWritePtr = cRxBuffer; // point to beginning of buffer
cRxBufferReadPtr = cRxBuffer;
cRxByteCnt = 0;
cRxIsrState = 0;
cRxMsgReady = NO;
cRxMsgTypeDesired = cCode;
enable_interrupts ( INT_RDA );
}
#separate char GetRxChar ( void )
{
// Get the next available byte in the recv fifo.
// Call this function ONLY if the recv fifo contains data.
char cValue;
cValue = 0;
if ( cRxByteCnt > 0 ) // For safety, check if there is any data
{
cValue = *cRxBufferReadPtr++; // Read byte from fifo
if ( cRxBufferReadPtr == ( cRxBuffer + RX_BUFFER_SIZE ) ) // Did tail ptr wrap ?
{
cRxBufferReadPtr = cRxBuffer; // If so, reset it to start of buffer
}
cRxByteCnt--; // Decrement byte count
}
return ( cValue );
}
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Cheers,
Ed |
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Sat Jan 14, 2006 11:44 am |
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| Quote: |
Here is the piece of code that I have been learning from. It's for a GPS compass. Unfortunately I can't remember who wrote it, so I can't credit them.
|
This code must be credited to Jon Fick (Westford MicroSystems).
I compiled the code as is, except that I add the directive for a pointer of 16 bit as follow:
#case
#include <16F628.H>
#device *=16
#include <jonsinc.h>
Following I post the code involved with rs232_errors:
| Code: | .................... #use rs232 ( baud=4800, xmit=PIN_B2, rcv=PIN_B1, ERRORS ) // XMIT must be assigned to enable hardward USART
*
0040: BTFSS PIR1.5
0041: GOTO 040
0042: MOVF RCSTA,W
0043: MOVWF rs232_errors
0044: MOVF RCREG,W
0045: MOVWF @78
0046: BTFSS rs232_errors.1
0047: GOTO 04A
0048: BCF RCSTA.4
0049: BSF RCSTA.4
004A: NOP
004B: GOTO 051 (RETURN)
*
|
You will see clearly:
0042: MOVF RCSTA,W
0043: MOVWF rs232_errors
where the compiler make a copy of RCSTA.
Then in the INT_RDA, Jon makes -by hand- a test of bit 2 (FERR) of the copy of RCSTA
looking for a frame error:
if ( rs232_errors & 0x04 ) or
BTFSS rs232_errors.2
Note that for test a bit he uses the same variable that CCS does internally,
just for saving RAM, wich is a good practice. Otherwise he would create a new one
and this would not make sense.
| Code: |
.................... if ( rs232_errors & 0x04 ) // get framing error bit from Rx status reg
*
004C: BTFSS 29.2
004D: GOTO 050
.................... {
.................... cRxErrorFlag = ON;
004E: MOVLW 01
004F: MOVWF cRxErrorFlag
.................... }
|
The sym list shows the name of the variable living at address 029.
| Code: |
027 @INTERRUPT_AREA
028 @INTERRUPT_AREA
029 rs232_errors
02A-033 cC
034 cTimeOut
035 cRxByteCnt
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Humberto |
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edhaslam
Joined: 15 Jul 2005
Posts: 89
Location: UK
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| Posted: Sun Jan 15, 2006 4:02 pm |
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Hi Humberto,
#device *=16 did the trick - can't believe I didn't think of that. Program runs fine now. I tried converting it to run on an 'F877A using a MAX232 and it's UART, but I can't get it to display the heading when I introduce a GPS signal. I know the GPS signal is valid and that the com port/coms connections work as they have been proven before. Is there anything I could be doing wrong when changing over to an F877A? Code changes:
| Code: |
#case
#include <16F877A.h>
#device *=16
#include <jonsinc.h>
#define EOF 0x00
#define COMMA ','
#define CR 13
#define SPACE ' '
#define PERIOD '.'
#define DOLLAR '$'
#define NULL 0
#define GPRMC_CODE 75
#define RX_BUFFER_SIZE 70
#define LED_N PIN_D0
#define LED_NE PIN_D1
#define LED_E PIN_D2
#define LED_SE PIN_D3
#define LED_S PIN_D4
#define LED_SW PIN_D5
#define LED_W PIN_D6
#define LED_NW PIN_D7
#define ROTATE_MS 30
//#define RX_IN PIN_B1
//#define PROG_CLK PIN_B6
//#define PROG_DAT PIN_B6
//#define PROG_MCLR PIN_A5
#separate char GetField ( void );
#separate void AllOff ( void );
#separate void GetHeading ( void );
#separate void DisplayHeading ( void );
#separate long TrueToMag ( long iH );
#separate long FieldFiveToLong ( void );
#separate void InitRxBuffer ( char cCode );
#separate char GetRxChar ( void );
#fuses HS, NOPROTECT, PUT, NOWDT, BROWNOUT, NOLVP, NOCPD //NOMCLR
#use standard_io ( A )
#use standard_io ( B )
#use delay ( clock = 8000000 )
#use rs232 ( baud=4800, xmit=PIN_C6, rcv=PIN_C7, ERRORS ) // XMIT must be assigned to enable hardward USART
static char cC [ 10 ]; // local buffer
static char cTimeOut;
static char cRxBuffer [ RX_BUFFER_SIZE ]; // Fifo
static char cRxByteCnt; // Number of bytes in the recv fifo
static char *cRxBufferWritePtr; // Pointers for the Rx buffer
static char *cRxBufferReadPtr;
static char cRxIsrState, cRxMsgTypeReceived, cRxMsgTypeDesired;
static char cRxMsgReady, cReceiveFlag;
static long iVar, iHdg;
static char cRxErrorFlag, cVarDir, cError;
/*******************************************************************/
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Mon Jan 16, 2006 9:01 am |
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| Quote: |
Program runs fine now.
|
Do you mean that the program compiled succesfully or the whole hardware + firmware
is running OK receiving GPS string and showing heading info?
| Quote: |
I tried converting it to run on an 'F877A using a MAX232 and it's UART, but I can't get it to display the heading when I introduce a GPS signal.
|
I can't see why it doesn't work in the 'F877A'. Did you make a simple test in the 'F877A' hardware
to be sure that it is properly wired and the oscillator working ?
Humberto |
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edhaslam
Joined: 15 Jul 2005
Posts: 89
Location: UK
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| Posted: Mon Jan 16, 2006 9:35 am |
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| Humberto wrote: |
Do you mean that the program compiled succesfully or the whole hardware + firmware
is running OK receiving GPS string and showing heading info?
|
It compiles and runs, but the program doesn't display the heading. When I send a gps stream of data, the D0 LED lights up. And when I stop the GPS signal, D0 goes out. That's it.
| Humberto wrote: |
I can't see why it doesn't work in the 'F877A'. Did you make a simple test in the 'F877A' hardware
to be sure that it is properly wired and the oscillator working ?
|
I know the harware is fine as I have it running on a dev board that I have been using for a long time now. Also, when the program runs you can see the 'direction' LEDs scroll as per this bit of code:
| Code: |
for ( cX = 0; cX < 5; cX++ )
{
output_low ( LED_NW ); output_high ( LED_N ); delay_ms ( ROTATE_MS );
output_low ( LED_N ); output_high ( LED_NE ); delay_ms ( ROTATE_MS );
output_low ( LED_NE ); output_high ( LED_E ); delay_ms ( ROTATE_MS );
output_low ( LED_E ); output_high ( LED_SE ); delay_ms ( ROTATE_MS );
output_low ( LED_SE ); output_high ( LED_S ); delay_ms ( ROTATE_MS );
output_low ( LED_S ); output_high ( LED_SW ); delay_ms ( ROTATE_MS );
output_low ( LED_SW ); output_high ( LED_W ); delay_ms ( ROTATE_MS );
output_low ( LED_W ); output_high ( LED_NW ); delay_ms ( ROTATE_MS );
}
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Humberto
Joined: 08 Sep 2003
Posts: 1215
Location: Buenos Aires, La Reina del Plata
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| Posted: Mon Jan 16, 2006 10:08 am |
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edhaslam,
The for loop is a piece of code before the main() just to see that the program had started. It doesn't do anymore.
I could start debugging the INT_RDA handler just to watch if something is arraiving. For example:
| Code: |
#int_rda
void SerialInterrupt ( void )
{
char cChar;
if ( rs232_errors & 0x04 ) // get framing error bit from Rx status reg
{
cRxErrorFlag = ON;
}
cChar = getchar(); // get char from UART, clear any errors
if(cChar == DOLLAR ) // if start of NMEA0183 message
{
output_high ( LED_n ); // Just to see if the first char of the GPS stream ('$') had arrived
}
..................................
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I can't help you anymore that in code because I didn't implement this code nor has
a GPS receiver to play with. May be somebody that had worked with this can help you.
Keep well,
Humberto |
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edhaslam
Joined: 15 Jul 2005
Posts: 89
Location: UK
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| Posted: Mon Jan 16, 2006 1:42 pm |
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| Humberto wrote: | edhaslam,
The for loop is a piece of code before the main() just to see that the program had started. It doesn't do anymore.
I could start debugging the INT_RDA handler just to watch if something is arraiving. For example:
| Code: |
#int_rda
void SerialInterrupt ( void )
{
char cChar;
if ( rs232_errors & 0x04 ) // get framing error bit from Rx status reg
{
cRxErrorFlag = ON;
}
cChar = getchar(); // get char from UART, clear any errors
if(cChar == DOLLAR ) // if start of NMEA0183 message
{
output_high ( LED_n ); // Just to see if the first char of the GPS stream ('$') had arrived
}
..................................
|
I can't help you anymore that in code because I didn't implement this code nor has
a GPS receiver to play with. May be somebody that had worked with this can help you.
Keep well,
Humberto |
Hi Humberto,
Many thanks - I'll try the RDA debugging code you suggested. I understand that it's hard to debug without seeing the hardware.
Many thanks again,
Ed |
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