Hi Matt,
you're welcome. I've rechecked your code, and your sequence of USART
initialization is not according to the manual yet. USART module enabling
is one of the last operations to be done, take a closer look in the guide.
As you're using a crystal oscilator, you have to add the algorithm
described on page 4-12 of the manual, otherwise the DCOCLK will be used.
I usually follow this sequence in my code:
1 - Initialize clock (page 4-12)
2 - Initialize I/O port registers (chapter 9)
3 - Initialize USART (page 13-4)
4 - Enter the main loop.
And as I said, you must not check the URXIFG0 in the Rx ISR, because it
will be always off when the ISR is executed. You have to rearrange your
ISR to take out this flag test.
Regards,
Adriano.
matthewbuza1 wrote:
> Adriano,
>
> Thank you for your help I cleaned up the code and went back to the
> guide for some help. I made the changes necessary, but when I hooked
> up the GPS there was no interrupt. I poked around and my ACLK is
> not ocsilating. I have the necessary caps on C1 and C2. I feel that
> it may due to the ordering of the UART
> setup. I had read before on another post if certain comments were
> out of order the UART could be unreliable. I feel I am so close to
> getting this to work. I've post the cleaned up code below, if anyone
> has any more suggestions, I would appreciate it. Thank you for the
> help that I have got so far. Best Regards - Matt
>
>
> #include <msp430x15x.h>
>
>
> ;NMEA, GPS defined Characters.
>
>
>
> #define Cc 43h
> #define Gg 47h
> #define Mm 4Dh
> #define Pp 50h
> #define Rr 52h
> #define comma 2Ch
> #define dollar 24h
> #define star 2Ah
>
>
>
> #define check_sum R15
> #define trans_val R14
> #define gpschar R13
> #define check_sum1 R12
> #define commas R11
> #define gpsfail R10
>
>
> SAVE EQU 200h
>
>
>
> ;--------------------------------
> ----------
> ORG 0C000h ; Progam Start
> ;--------------------------------
> ----------
> RESET mov.w #0400h,SP ; Initialize stackpointer
> StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
>
> ;page 13-4 of the user guide. Setup USART.
>
> SetupUART0 bis.b #SWRST,&UCTL0 ; Set SWRST, set SWRST
> to 1.
> bis.b #UTXE0+URXE0,&ME1 ; Enable USART0
> TXD/RXD
> bic.b #SWRST,&UCTL0 ; Set SWRST
> bis.b #URXIE0,&IE1
> bis.b #CHAR,&UCTL0 ; 8-bit char
> ;bis.b #SSEL1,&UTCTL0 ; UCLK = SMCLK
> ;mov.b #0D0h,&UBR00 ; 2MHz 9600
> ;mov.b #000h,&UBR10 ;
> ;mov.b #000h,&UMCTL0 ; no modulation
> bis.b #SSEL0,&UTCTL0 ; UCLK = ACLK
> mov.b #006h,&UBR00 ; 32k/4800 - 6.8267
> mov.b #000h,&UBR10 ;
> mov.b #06Fh,&UMCTL0 ; modulation
>
> ;Setup P1 pins, and USART pins.
>
> SetupP1 bis.b #00Fh,&P1DIR ;all P1 pins set to
> output
> bic.b #00Fh,&P1OUT ;Clear all the p1 pins
> SetupP3 bis.b #030h,&P3SEL ; P3.4,5 = USART0 TXD/RXD
> bis.b #010h,&P3DIR
>
>
> ;looking to output a value to the Transmit pin (33) on micro-
> controller.
> ;hoping to see voltage output from pin. Read by multimeter.
>
> Mainloop bis.w #CPUOFF+GIE,SR ; Enter LPM0(low power
> mode), interrupts enabled
> nop
>
> ;--------------------------------
> ----------
> USART0RX_ISR; Starting NMEA command for the GPS.
> ;--------------------------------
> ----------
>
> ;Begin GPS and look for first Edge detect. Once edge detect is found
> start main
> ;gps reading loop. URXIFGO flag is set to zero when an interrupt is
> detected.
>
>
> ;Edge was detected
> ;Setting constants
> GPSloop mov.b #00h,check_sum1
> mov.b #00h,R5
> mov.b #00h,commas
>
> ;Testing to see if the character is in the buffer,
> URXIFGO=1.
>
> edgedet0 bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
> jnz dllrchar ;jumps when flag is set to
> 1, whole character is in the RX Buffer.
> jmp edgedet0
>
> ;capturing the character
>
> dllrchar mov.b &U0RXBUF,gpschar ;move data from buffer to
> register
> cmp.b #dollar,gpschar ;compare received data
> with expected
> jeq flagdllr ;jump to set flag
> jmp fin ;bad data start over
>
> ;Saving the Character
>
> flagdllr mov.b gpschar,SAVE(R5) ;saving data
> inc R5 ;increment for next save
>
> fin reti
>
> ;--------------------------------
> ----------
> ; Interrupt Vectors
> ;--------------------------------
> ----------
> ORG 0FFFEh ;
> DW RESET ; POR, ext. Reset,
> Watchdog
> ORG 0FFF2h ;
> DW USART0RX_ISR ; go to edge detect
> END
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> --- In msp430@msp4..., Adriano Caye <adriano@n...> wrote:
>
>>Hi Matthew,
>>
>>I'll say some comments about your code:
>>
>>1 - there is a correct sequence to initialize UART registers, and
>
> you're
>
>>not quite following this sequence. Look at the page 13-4 of the
>
> user's
>
>>guide.
>>
>>2 - It seems you're not using the DCO as the BRCLK. So, you
don't
>
> need
>
>>to enable the receive-start edge detect feature.
>>
>>3 - In your GPSREAD function, you have to put a RET instruction in
>
> the
>
>>end of the subroutine. It's not very good practice though to call
>>subroutines inside an ISR. It should be as fast as possible, to be
>
> able
>
>>to receive other characters.
>>
>>4 - You don't have to check for the URXIFG0 bit in the ISR.
It'll
>
> be
>
>>always off, as the page 13-18 of the user's guide states. When the
>
> ISR
>
>>is called, that flag is automatically turned off.
>>
>>Regards,
>>Adriano.
>>
>>
>>matthewbuza1 wrote:
>>
>>>I am working to incorporate navman callisto gps with the
>
> msp430x15.
>
>>>I was new to the entire emmbedded programming until a month ago.
>
> So
>
>>>I have had to learn the programming and microcontroller pretty
>
> fast.
>
>>>By no means am I proficient. I have searched and viewed a ton of
>>>postings via this group. First I am not a student and this is
>
> not
>
>>>for a class. I have attached my code below. I beleive i've set
>
> the
>
>>>baud rate correctly, it has to be 4800 for the navman. My
>
> question
>
>>>is that the URXIFG0 flag in the IFG1 register is setting to 1,
>>>signifiying an accepted character. I feel i have set up the edge
>>>detect correctly. In the user manual page 13-19 i followed their
>>>pattern. Although when the interrupt is sounded and the sub-
>
> routine
>
>>>is called, I loop and wait for the URXIFG0 flag to be triggered
>
> to 1
>
>>>signifying a character in the RX buffer. Also when i debug, i
>
> look
>
>>>at the RX address and my character from the gps is never
>
> received.
>
>>>My programming is simplified down, I am trying to read in the
>
> first
>
>>>character which is a dollar sign and save in into memory. Any
>
> help
>
>>>would be greatly appreciated. Thank you. -Matt
>>>
>>>#include <msp430x15x.h>
>>>
>>>
>>>;NMEA, GPS defined Characters.
>>>
>>>
>>>
>>>#define Cc 43h
>>>#define Gg 47h
>>>#define Mm 4Dh
>>>#define Pp 50h
>>>#define Rr 52h
>>>#define comma 2Ch
>>>#define dollar 24h
>>>#define star 2Ah
>>>
>>>
>>>
>>>#define check_sum R15
>>>#define trans_val R14
>>>#define gpschar R13
>>>#define check_sum1 R12
>>>#define commas R11
>>>#define gpsfail R10
>>>
>>>
>>>SAVE EQU 200h
>>>
>>>
>>>
>>>;----------------------------
>
> ----
>
>>>----------
>>> ORG 0C000h ; Progam Start
>>>;----------------------------
>
> ----
>
>>>----------
>>>RESET mov.w #0A00h,SP ; Initialize
>
> stackpointer
>
>>>StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
>>>
>>>SetupUART0 bis.b #UTXE0+URXE0,&ME1 ; Enable USART0
>
> TXD/RXD
>
>>> bis.b #CHAR,&UCTL0 ; 8-bit characters
>>> mov.b #SSEL0,&UTCTL0 ; UCLK = ACLK
>>> mov.b #006h,&UBR00 ; 32k/4800 - 6.8267
>>> mov.b #000h,&UBR10 ;
>>> mov.b #077h,&UMCTL0 ; modulation
>>> bic.b #SWRST,&UCTL0 ; **Initialize USART
>>>state machine**
>>> bis.b #URXIE0,&IE1 ; Enable USART0 RX
>>>interrupt
>>>SetupP1 bis.b #00Fh,&P1DIR ;all P1 pins set to
>>>output
>>> bic.b #00Fh,&P1OUT ;Clear all the p1
>
> pins
>
>>>SetupP3 bis.b #030h,&P3SEL ; P3.4,5 = USART0
>
> TXD/RXD
>
>>> bis.b #010h,&P3DIR
>>>
>>>
>>>
>>>
>>>beginedge bic.b #URXSE,&U0TCTL ;clears edge detect
>
> for
>
>>>whole program
>>> bis.b #URXSE,&U0TCTL ;re-enable edge
>>>detect
>>>R5setup mov.b #00h,R5
>>>
>>>
>>>
>>>;looking to output a value to the Transmit pin (33) on micro-
>>>controller.
>>>;hoping to see voltage output from pin. Read by multimeter.
>>>
>>>
>>>
>>>Mainloop bis.w #CPUOFF+GIE,SR ; Enter LPM0(low
>
> power
>
>>>mode), interrupts enabled
>>> nop
>>>
>>>
>>>;----------------------------
>
> ----
>
>>>----------
>>>GPSREAD; Starting NMEA command for the GPS.
>>>;----------------------------
>
> ----
>
>>>----------
>>>
>>> xor.b #001h,&P1OUT ;Toggle P1.0, turns
>
> on
>
>>>GPS via transistor
>>>
>>>GPSloop mov.b #00h,check_sum1
>>> mov.b #00h,R5
>>> mov.b #00h,commas
>>> jmp edgedet0
>>>
>>>
>>>edgedet0 bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
>>> jnz dllrchar
>>> jmp edgedet0
>>>dllrchar mov.b &U0RXBUF,gpschar ;move data from buffer
>
> to
>
>>>register
>>> cmp.b #dollar,gpschar ;compare received data
>>>with expected
>>> jeq flagdllr ;jump to set flag
>>> jmp mastercnt ;bad data start over
>>>flagdllr mov.b gpschar,SAVE(R5) ;saving data
>>> inc R5 ;increment for next
>
> save
>
>>>URXSECLEAR9 bic.b #URXSE,&U0TCTL ;clear urxs signal
>>> bis.b #URXSE,&U0TCTL ;re-enable edge detect
>>>
>>>mastercnt mov.b #001h,R15
>>>
>>>
>>>;----------------------------
>
> ----
>
>>>----------
>>>USART0RX_ISR; Detects the edge of a gps signal
>>>;----------------------------
>
> ----
>
>>>----------
>>>
>>>
>>>;Begin GPS and look for first Edge detect. Once edge detect is
>
> found
>
>>>start main
>>>;gps reading loop.
>>>
>>>edgedet bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
>>> jz URXSECLEAR
>>> jmp calling
>>>
>>>;RESET EDGE DETECT
>>>
>>>URXSECLEAR bic.b #URXSE,&U0TCTL ;clear urxs signal
>>> bis.b #URXSE,&U0TCTL ;re-enable edge detect
>>> bic #SCG0+SCG1,0(SP) ;ENABLE BRCLK
>>>calling call #GPSREAD ;character is in RX
>
> buffer
>
>>>go to read and save.
>>> reti
>>>
>>>;----------------------------
>
> ----
>
>>>----------
>>>; Interrupt Vectors
>>>;----------------------------
>
> ----
>
>>>----------
>>> ORG 0FFFEh ;
>>> DW RESET ; POR, ext. Reset,
>>>Watchdog
>>> ORG 0FFF2h ;
>>> DW USART0RX_ISR ; go to edge detect
>>> END
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>.
>>>
>>>
>>>Yahoo! Groups Links
>>>
>>>
>>>
>>>
>>>
>>>
>>
>
>
>
>
>
>
>
> .
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
Adriano,
Thank you for your help I cleaned up the code and went back to the
guide for some help. I made the changes necessary, but when I hooked
up the GPS there was no interrupt. I poked around and my ACLK is
not ocsilating. I have the necessary caps on C1 and C2. I feel that
it may due to the ordering of the UART
setup. I had read before on another post if certain comments were
out of order the UART could be unreliable. I feel I am so close to
getting this to work. I've post the cleaned up code below, if anyone
has any more suggestions, I would appreciate it. Thank you for the
help that I have got so far. Best Regards - Matt
#include <msp430x15x.h>
;NMEA, GPS defined Characters.
#define Cc 43h
#define Gg 47h
#define Mm 4Dh
#define Pp 50h
#define Rr 52h
#define comma 2Ch
#define dollar 24h
#define star 2Ah
#define check_sum R15
#define trans_val R14
#define gpschar R13
#define check_sum1 R12
#define commas R11
#define gpsfail R10
SAVE EQU 200h
;--------------------------------
----------
ORG 0C000h ; Progam Start
;--------------------------------
----------
RESET mov.w #0400h,SP ; Initialize stackpointer
StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
;page 13-4 of the user guide. Setup USART.
SetupUART0 bis.b #SWRST,&UCTL0 ; Set SWRST, set SWRST
to 1.
bis.b #UTXE0+URXE0,&ME1 ; Enable USART0
TXD/RXD
bic.b #SWRST,&UCTL0 ; Set SWRST
bis.b #URXIE0,&IE1
bis.b #CHAR,&UCTL0 ; 8-bit char
;bis.b #SSEL1,&UTCTL0 ; UCLK = SMCLK
;mov.b #0D0h,&UBR00 ; 2MHz 9600
;mov.b #000h,&UBR10 ;
;mov.b #000h,&UMCTL0 ; no modulation
bis.b #SSEL0,&UTCTL0 ; UCLK = ACLK
mov.b #006h,&UBR00 ; 32k/4800 - 6.8267
mov.b #000h,&UBR10 ;
mov.b #06Fh,&UMCTL0 ; modulation
;Setup P1 pins, and USART pins.
SetupP1 bis.b #00Fh,&P1DIR ;all P1 pins set to
output
bic.b #00Fh,&P1OUT ;Clear all the p1 pins
SetupP3 bis.b #030h,&P3SEL ; P3.4,5 = USART0 TXD/RXD
bis.b #010h,&P3DIR
;looking to output a value to the Transmit pin (33) on micro-
controller.
;hoping to see voltage output from pin. Read by multimeter.
Mainloop bis.w #CPUOFF+GIE,SR ; Enter LPM0(low power
mode), interrupts enabled
nop
;--------------------------------
----------
USART0RX_ISR; Starting NMEA command for the GPS.
;--------------------------------
----------
;Begin GPS and look for first Edge detect. Once edge detect is found
start main
;gps reading loop. URXIFGO flag is set to zero when an interrupt is
detected.
;Edge was detected
;Setting constants
GPSloop mov.b #00h,check_sum1
mov.b #00h,R5
mov.b #00h,commas
;Testing to see if the character is in the buffer,
URXIFGO=1.
edgedet0 bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
jnz dllrchar ;jumps when flag is set to
1, whole character is in the RX Buffer.
jmp edgedet0
;capturing the character
dllrchar mov.b &U0RXBUF,gpschar ;move data from buffer to
register
cmp.b #dollar,gpschar ;compare received data
with expected
jeq flagdllr ;jump to set flag
jmp fin ;bad data start over
;Saving the Character
flagdllr mov.b gpschar,SAVE(R5) ;saving data
inc R5 ;increment for next save
fin reti
;--------------------------------
----------
; Interrupt Vectors
;--------------------------------
----------
ORG 0FFFEh ;
DW RESET ; POR, ext. Reset,
Watchdog
ORG 0FFF2h ;
DW USART0RX_ISR ; go to edge detect
END
--- In msp430@msp4..., Adriano Caye <adriano@n...> wrote:
>
> Hi Matthew,
>
> I'll say some comments about your code:
>
> 1 - there is a correct sequence to initialize UART registers, and
you're
> not quite following this sequence. Look at the
page 13-4 of the
user's
> guide.
>
> 2 - It seems you're not using the DCO as the BRCLK. So, you don't
need
> to enable the receive-start edge detect feature.
>
> 3 - In your GPSREAD function, you have to put a RET instruction in
the
> end of the subroutine. It's not very good
practice though to call
> subroutines inside an ISR. It should be as fast as possible, to be
able
> to receive other characters.
>
> 4 - You don't have to check for the URXIFG0 bit in the ISR. It'll
be
> always off, as the page 13-18 of the user's
guide states. When the
ISR
> is called, that flag is automatically turned off.
>
> Regards,
> Adriano.
>
>
> matthewbuza1 wrote:
> > I am working to incorporate navman callisto gps with the
msp430x15.
> > I was new to the entire emmbedded programming
until a month ago.
So
> > I have had to learn the programming and
microcontroller pretty
fast.
> > By no means am I proficient. I have searched
and viewed a ton of
> > postings via this group. First I am not a student and this is
not
> > for a class. I have attached my code below. I
beleive i've set
the
> > baud rate correctly, it has to be 4800 for
the navman. My
question
> > is that the URXIFG0 flag in the IFG1 register
is setting to 1,
> > signifiying an accepted character. I feel i have set up the edge
> > detect correctly. In the user manual page 13-19 i followed their
> > pattern. Although when the interrupt is sounded and the sub-
routine
> > is called, I loop and wait for the URXIFG0
flag to be triggered
to 1
> > signifying a character in the RX buffer. Also
when i debug, i
look
> > at the RX address and my character from the
gps is never
received.
> > My programming is simplified down, I am
trying to read in the
first
> > character which is a dollar sign and save in
into memory. Any
help
> > would be greatly appreciated. Thank you.
-Matt
> >
> > #include <msp430x15x.h>
> >
> >
> > ;NMEA, GPS defined Characters.
> >
> >
> >
> > #define Cc 43h
> > #define Gg 47h
> > #define Mm 4Dh
> > #define Pp 50h
> > #define Rr 52h
> > #define comma 2Ch
> > #define dollar 24h
> > #define star 2Ah
> >
> >
> >
> > #define check_sum R15
> > #define trans_val R14
> > #define gpschar R13
> > #define check_sum1 R12
> > #define commas R11
> > #define gpsfail R10
> >
> >
> > SAVE EQU 200h
> >
> >
> >
> > ;----------------------------
----
> > ----------
> > ORG 0C000h ; Progam Start
> > ;----------------------------
----
> > ----------
> > RESET mov.w #0A00h,SP ; Initialize
stackpointer
> > StopWDT mov.w
#WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
> >
> > SetupUART0 bis.b #UTXE0+URXE0,&ME1 ; Enable USART0
TXD/RXD
> > bis.b #CHAR,&UCTL0
; 8-bit characters
> > mov.b #SSEL0,&UTCTL0 ; UCLK = ACLK
> > mov.b #006h,&UBR00 ; 32k/4800 - 6.8267
> > mov.b #000h,&UBR10 ;
> > mov.b #077h,&UMCTL0 ; modulation
> > bic.b #SWRST,&UCTL0 ; **Initialize USART
> > state machine**
> > bis.b #URXIE0,&IE1 ; Enable USART0 RX
> > interrupt
> > SetupP1 bis.b #00Fh,&P1DIR ;all P1 pins set to
> > output
> > bic.b #00Fh,&P1OUT ;Clear all the p1
pins
> > SetupP3 bis.b #030h,&P3SEL
; P3.4,5 = USART0
TXD/RXD
> > bis.b #010h,&P3DIR
> >
> >
> >
> >
> > beginedge bic.b #URXSE,&U0TCTL ;clears edge detect
for
> > whole program
> > bis.b #URXSE,&U0TCTL ;re-enable edge
> > detect
> > R5setup mov.b #00h,R5
> >
> >
> >
> > ;looking to output a value to the Transmit pin (33) on micro-
> > controller.
> > ;hoping to see voltage output from pin. Read by multimeter.
> >
> >
> >
> > Mainloop bis.w #CPUOFF+GIE,SR ; Enter LPM0(low
power
> > mode), interrupts enabled
> > nop
> >
> >
> > ;----------------------------
----
> > ----------
> > GPSREAD; Starting NMEA command for the GPS.
> > ;----------------------------
----
> > ----------
> >
> > xor.b #001h,&P1OUT ;Toggle P1.0, turns
on
> > GPS via transistor
> >
> > GPSloop mov.b #00h,check_sum1
> > mov.b #00h,R5
> > mov.b #00h,commas
> > jmp edgedet0
> >
> >
> > edgedet0 bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
> > jnz dllrchar
> > jmp edgedet0
> > dllrchar mov.b &U0RXBUF,gpschar ;move data from buffer
to
> > register
> > cmp.b #dollar,gpschar ;compare received data
> > with expected
> > jeq flagdllr ;jump to set flag
> > jmp mastercnt ;bad data start over
> > flagdllr mov.b gpschar,SAVE(R5) ;saving data
> > inc R5 ;increment for next
save
> > URXSECLEAR9 bic.b #URXSE,&U0TCTL
;clear urxs signal
> > bis.b #URXSE,&U0TCTL ;re-enable edge detect
> >
> > mastercnt mov.b #001h,R15
> >
> >
> > ;----------------------------
----
> > ----------
> > USART0RX_ISR; Detects the edge of a gps signal
> > ;----------------------------
----
> > ----------
> >
> >
> > ;Begin GPS and look for first Edge detect. Once edge detect is
found
> > start main
> > ;gps reading loop.
> >
> > edgedet bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
> > jz URXSECLEAR
> > jmp calling
> >
> > ;RESET EDGE DETECT
> >
> > URXSECLEAR bic.b #URXSE,&U0TCTL ;clear urxs signal
> > bis.b #URXSE,&U0TCTL ;re-enable edge detect
> > bic #SCG0+SCG1,0(SP) ;ENABLE BRCLK
> > calling call #GPSREAD ;character is in RX
buffer
> > go to read and save.
> > reti
> >
> > ;----------------------------
----
> > ----------
> > ; Interrupt Vectors
> > ;----------------------------
----
> > ----------
> > ORG 0FFFEh ;
> > DW RESET ; POR, ext. Reset,
> > Watchdog
> > ORG 0FFF2h ;
> > DW USART0RX_ISR ; go to edge detect
> > END
> >
> >
> >
> >
> >
> >
> >
> >
> > .
> >
> >
> > Yahoo! Groups Links
> >
> >
> >
> >
> >
> >
>
Reply by Adriano Caye●December 8, 20052005-12-08
Hi Matthew,
I'll say some comments about your code:
1 - there is a correct sequence to initialize UART registers, and you're
not quite following this sequence. Look at the page 13-4 of the user's
guide.
2 - It seems you're not using the DCO as the BRCLK. So, you don't need
to enable the receive-start edge detect feature.
3 - In your GPSREAD function, you have to put a RET instruction in the
end of the subroutine. It's not very good practice though to call
subroutines inside an ISR. It should be as fast as possible, to be able
to receive other characters.
4 - You don't have to check for the URXIFG0 bit in the ISR. It'll be
always off, as the page 13-18 of the user's guide states. When the ISR
is called, that flag is automatically turned off.
Regards,
Adriano.
matthewbuza1 wrote:
> I am working to incorporate navman callisto gps with the msp430x15.
> I was new to the entire emmbedded programming until a month ago. So
> I have had to learn the programming and microcontroller pretty fast.
> By no means am I proficient. I have searched and viewed a ton of
> postings via this group. First I am not a student and this is not
> for a class. I have attached my code below. I beleive i've set the
> baud rate correctly, it has to be 4800 for the navman. My question
> is that the URXIFG0 flag in the IFG1 register is setting to 1,
> signifiying an accepted character. I feel i have set up the edge
> detect correctly. In the user manual page 13-19 i followed their
> pattern. Although when the interrupt is sounded and the sub-routine
> is called, I loop and wait for the URXIFG0 flag to be triggered to 1
> signifying a character in the RX buffer. Also when i debug, i look
> at the RX address and my character from the gps is never received.
> My programming is simplified down, I am trying to read in the first
> character which is a dollar sign and save in into memory. Any help
> would be greatly appreciated. Thank you. -Matt
>
> #include <msp430x15x.h>
>
>
> ;NMEA, GPS defined Characters.
>
>
>
> #define Cc 43h
> #define Gg 47h
> #define Mm 4Dh
> #define Pp 50h
> #define Rr 52h
> #define comma 2Ch
> #define dollar 24h
> #define star 2Ah
>
>
>
> #define check_sum R15
> #define trans_val R14
> #define gpschar R13
> #define check_sum1 R12
> #define commas R11
> #define gpsfail R10
>
>
> SAVE EQU 200h
>
>
>
> ;--------------------------------
> ----------
> ORG 0C000h ; Progam Start
> ;--------------------------------
> ----------
> RESET mov.w #0A00h,SP ; Initialize stackpointer
> StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
>
> SetupUART0 bis.b #UTXE0+URXE0,&ME1 ; Enable USART0 TXD/RXD
> bis.b #CHAR,&UCTL0 ; 8-bit characters
> mov.b #SSEL0,&UTCTL0 ; UCLK = ACLK
> mov.b #006h,&UBR00 ; 32k/4800 - 6.8267
> mov.b #000h,&UBR10 ;
> mov.b #077h,&UMCTL0 ; modulation
> bic.b #SWRST,&UCTL0 ; **Initialize USART
> state machine**
> bis.b #URXIE0,&IE1 ; Enable USART0 RX
> interrupt
> SetupP1 bis.b #00Fh,&P1DIR ;all P1 pins set to
> output
> bic.b #00Fh,&P1OUT ;Clear all the p1 pins
> SetupP3 bis.b #030h,&P3SEL ; P3.4,5 = USART0 TXD/RXD
> bis.b #010h,&P3DIR
>
>
>
>
> beginedge bic.b #URXSE,&U0TCTL ;clears edge detect for
> whole program
> bis.b #URXSE,&U0TCTL ;re-enable edge
> detect
> R5setup mov.b #00h,R5
>
>
>
> ;looking to output a value to the Transmit pin (33) on micro-
> controller.
> ;hoping to see voltage output from pin. Read by multimeter.
>
>
>
> Mainloop bis.w #CPUOFF+GIE,SR ; Enter LPM0(low power
> mode), interrupts enabled
> nop
>
>
> ;--------------------------------
> ----------
> GPSREAD; Starting NMEA command for the GPS.
> ;--------------------------------
> ----------
>
> xor.b #001h,&P1OUT ;Toggle P1.0, turns on
> GPS via transistor
>
> GPSloop mov.b #00h,check_sum1
> mov.b #00h,R5
> mov.b #00h,commas
> jmp edgedet0
>
>
> edgedet0 bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
> jnz dllrchar
> jmp edgedet0
> dllrchar mov.b &U0RXBUF,gpschar ;move data from buffer to
> register
> cmp.b #dollar,gpschar ;compare received data
> with expected
> jeq flagdllr ;jump to set flag
> jmp mastercnt ;bad data start over
> flagdllr mov.b gpschar,SAVE(R5) ;saving data
> inc R5 ;increment for next save
> URXSECLEAR9 bic.b #URXSE,&U0TCTL ;clear urxs signal
> bis.b #URXSE,&U0TCTL ;re-enable edge detect
>
> mastercnt mov.b #001h,R15
>
>
> ;--------------------------------
> ----------
> USART0RX_ISR; Detects the edge of a gps signal
> ;--------------------------------
> ----------
>
>
> ;Begin GPS and look for first Edge detect. Once edge detect is found
> start main
> ;gps reading loop.
>
> edgedet bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
> jz URXSECLEAR
> jmp calling
>
> ;RESET EDGE DETECT
>
> URXSECLEAR bic.b #URXSE,&U0TCTL ;clear urxs signal
> bis.b #URXSE,&U0TCTL ;re-enable edge detect
> bic #SCG0+SCG1,0(SP) ;ENABLE BRCLK
> calling call #GPSREAD ;character is in RX buffer
> go to read and save.
> reti
>
> ;--------------------------------
> ----------
> ; Interrupt Vectors
> ;--------------------------------
> ----------
> ORG 0FFFEh ;
> DW RESET ; POR, ext. Reset,
> Watchdog
> ORG 0FFF2h ;
> DW USART0RX_ISR ; go to edge detect
> END
>
>
>
>
>
>
>
>
> .
>
>
> Yahoo! Groups Links
>
>
>
>
>
>
Reply by matthewbuza1●December 7, 20052005-12-07
I am working to incorporate navman callisto gps with the msp430x15.
I was new to the entire emmbedded programming until a month ago. So
I have had to learn the programming and microcontroller pretty fast.
By no means am I proficient. I have searched and viewed a ton of
postings via this group. First I am not a student and this is not
for a class. I have attached my code below. I beleive i've set the
baud rate correctly, it has to be 4800 for the navman. My question
is that the URXIFG0 flag in the IFG1 register is setting to 1,
signifiying an accepted character. I feel i have set up the edge
detect correctly. In the user manual page 13-19 i followed their
pattern. Although when the interrupt is sounded and the sub-routine
is called, I loop and wait for the URXIFG0 flag to be triggered to 1
signifying a character in the RX buffer. Also when i debug, i look
at the RX address and my character from the gps is never received.
My programming is simplified down, I am trying to read in the first
character which is a dollar sign and save in into memory. Any help
would be greatly appreciated. Thank you. -Matt
#include <msp430x15x.h>
;NMEA, GPS defined Characters.
#define Cc 43h
#define Gg 47h
#define Mm 4Dh
#define Pp 50h
#define Rr 52h
#define comma 2Ch
#define dollar 24h
#define star 2Ah
#define check_sum R15
#define trans_val R14
#define gpschar R13
#define check_sum1 R12
#define commas R11
#define gpsfail R10
SAVE EQU 200h
;--------------------------------
----------
ORG 0C000h ; Progam Start
;--------------------------------
----------
RESET mov.w #0A00h,SP ; Initialize stackpointer
StopWDT mov.w #WDTPW+WDTHOLD,&WDTCTL ; Stop WDT
SetupUART0 bis.b #UTXE0+URXE0,&ME1 ; Enable USART0 TXD/RXD
bis.b #CHAR,&UCTL0 ; 8-bit characters
mov.b #SSEL0,&UTCTL0 ; UCLK = ACLK
mov.b #006h,&UBR00 ; 32k/4800 - 6.8267
mov.b #000h,&UBR10 ;
mov.b #077h,&UMCTL0 ; modulation
bic.b #SWRST,&UCTL0 ; **Initialize USART
state machine**
bis.b #URXIE0,&IE1 ; Enable USART0 RX
interrupt
SetupP1 bis.b #00Fh,&P1DIR ;all P1 pins set to
output
bic.b #00Fh,&P1OUT ;Clear all the p1 pins
SetupP3 bis.b #030h,&P3SEL ; P3.4,5 = USART0 TXD/RXD
bis.b #010h,&P3DIR
beginedge bic.b #URXSE,&U0TCTL ;clears edge detect for
whole program
bis.b #URXSE,&U0TCTL ;re-enable edge
detect
R5setup mov.b #00h,R5
;looking to output a value to the Transmit pin (33) on micro-
controller.
;hoping to see voltage output from pin. Read by multimeter.
Mainloop bis.w #CPUOFF+GIE,SR ; Enter LPM0(low power
mode), interrupts enabled
nop
;--------------------------------
----------
GPSREAD; Starting NMEA command for the GPS.
;--------------------------------
----------
xor.b #001h,&P1OUT ;Toggle P1.0, turns on
GPS via transistor
GPSloop mov.b #00h,check_sum1
mov.b #00h,R5
mov.b #00h,commas
jmp edgedet0
edgedet0 bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
jnz dllrchar
jmp edgedet0
dllrchar mov.b &U0RXBUF,gpschar ;move data from buffer to
register
cmp.b #dollar,gpschar ;compare received data
with expected
jeq flagdllr ;jump to set flag
jmp mastercnt ;bad data start over
flagdllr mov.b gpschar,SAVE(R5) ;saving data
inc R5 ;increment for next save
URXSECLEAR9 bic.b #URXSE,&U0TCTL ;clear urxs signal
bis.b #URXSE,&U0TCTL ;re-enable edge detect
mastercnt mov.b #001h,R15
;--------------------------------
----------
USART0RX_ISR; Detects the edge of a gps signal
;--------------------------------
----------
;Begin GPS and look for first Edge detect. Once edge detect is found
start main
;gps reading loop.
edgedet bit.b #URXIFG0,&IFG1 ;TESTING URXIFGx
jz URXSECLEAR
jmp calling
;RESET EDGE DETECT
URXSECLEAR bic.b #URXSE,&U0TCTL ;clear urxs signal
bis.b #URXSE,&U0TCTL ;re-enable edge detect
bic #SCG0+SCG1,0(SP) ;ENABLE BRCLK
calling call #GPSREAD ;character is in RX buffer
go to read and save.
reti
;--------------------------------
----------
; Interrupt Vectors
;--------------------------------
----------
ORG 0FFFEh ;
DW RESET ; POR, ext. Reset,
Watchdog
ORG 0FFF2h ;
DW USART0RX_ISR ; go to edge detect
END
