GPS Project: PIC18F26K22 or PIC18F46K22

[astanapane]

Dear all,

i did the following....

'*-----------------------------------------------------------------------------|
'*                        |  --------------------- |                           |
'*----------------------- | EUART 1 Configuration  | --------------------------|
'*                        |  --------------------- |                           |
'*-----------------------------------------------------------------------------|
        
        RCSTA = $90 ' Enable serial port & continuous receive
        TXSTA = $24 ' Enable transmit, BRGH = 1
        'CLROERR = 1 ' Clear overflow automatically
        SPBRG = 160 ' 38400 Baud @ 64MHz, -0,08%
        SPBRGH = 1
        BAUDCON.3 = 1         ' Enable 16 bit baudrate generator
        
'*-----------------------------------------------------------------------------|
'*                        |  --------------------- |                           |
'*----------------------- | EUART 2 Configuration  | --------------------------|
'*                        |  --------------------- |                           |
'*-----------------------------------------------------------------------------|

        RCSTA2 = $90 ' Enable serial port & continuous receive
        TXSTA2 = $24 ' Enable transmit, BRGH = 1
        'CLROERR2 1 ' Clear overflow automatically
        SPBRG2 = 130 ' 9600 Baud @ 64MHz, -0,02%
        SPBRGH2 = 6
        BAUDCON2.3 = 1         ' Enable 16 bit baudrate generator
        

'------------------------------------------------------------------------------|
'-----------sent a sentence to gps, this is not working at the moment----------|
'------------------------------------------------------------------------------|
' When the GPS Module is POWERED ON, then the following sentenses are received. 

'          $PMTK011,MTKGPS*08
'          $PMTK010,001*2E
'          $PMTK010,002*2D   

pause 800 
HSEROUT2 ["$PMTK251,38400*27",13,10]      ' 38400 boundrate, check MTK manual configuration
pause 800

SPBRG2 = 160 ' 38400 Baud @ 64MHz, -0,08%
Pause 500

HSEROUT2 ["$PMTK220,100*2F",13,10]        ' 100(millisecond)=0.1(sec)-->1/0.1= 10Hz
pause 100

It works the part of a baudrate change, when i send the command to the gps

HSEROUT2 ["$PMTK251,38400*27",13,10]      ' 38400 boundrate, check MTK manual configuration
pause 800

but i think the following it goes to GPS but for some reason is not set.

HSEROUT2 ["$PMTK220,100*2F",13,10]        ' 100(millisecond)=0.1(sec)-->1/0.1= 10Hz
pause 100

[tumbleweed]

When you switch the baudrate you have to set both SPBRG2 and SPBRGH2.

Try:

SPBRG2 = 160 ' 38400 Baud @ 64MHz, -0,08%
SPBRGH2 = 1
Pause 500

[astanapane]

When you switch the baudrate you have to set both SPBRG2 and SPBRGH2.

Try:

SPBRG2 = 160 ' 38400 Baud @ 64MHz, -0,08%
SPBRGH2 = 1
Pause 500

It worked!!! I will post later on what i have done up to now. Maybe i need to set up a small indication when those commands are set. So i know that program is working up to that stage.

This is the code for changing the baudrate to GPS and the hz rate at 10Hz at the NMEA data.

'*-----------------------------------------------------------------------------|
'*                        |  --------------------- |                           |
'*----------------------- | EUART 1 Configuration  | --------------------------|
'*                        |  --------------------- |                           |
'*-----------------------------------------------------------------------------|
        
        RCSTA = $90 ' Enable serial port & continuous receive
        TXSTA = $24 ' Enable transmit, BRGH = 1
        'CLROERR = 1 ' Clear overflow automatically
        SPBRG = 160 ' 38400 Baud @ 64MHz, -0,08%
        SPBRGH = 1
        BAUDCON.3 = 1         ' Enable 16 bit baudrate generator
        
'*-----------------------------------------------------------------------------|
'*                        |  --------------------- |                           |
'*----------------------- | EUART 2 Configuration  | --------------------------|
'*                        |  --------------------- |                           |
'*-----------------------------------------------------------------------------|

        RCSTA2 = $90 ' Enable serial port & continuous receive
        TXSTA2 = $24 ' Enable transmit, BRGH = 1
        'CLROERR2 1 ' Clear overflow automatically
        SPBRG2 = 130 ' 9600 Baud @ 64MHz, -0,02%
        SPBRGH2 = 6
        BAUDCON2.3 = 1         ' Enable 16 bit baudrate generator
        

'------------------------------------------------------------------------------|
'-----------sent a sentence to gps, this is not working at the moment----------|
'------------------------------------------------------------------------------|
' When the GPS Module is POWERED ON, then the following sentenses are received. 

'          $PMTK011,MTKGPS*08
'          $PMTK010,001*2E
'          $PMTK010,002*2D   

pause 800 
HSEROUT2 ["$PMTK251,38400*27",13,10]      ' 38400 boundrate, check MTK manual configuration
pause 800

SPBRG2 = 160 ' 38400 Baud @ 64MHz, -0,08%
SPBRGH2 = 1
Pause 500

HSEROUT2 ["$PMTK220,100*2F",13,10]        ' 100(millisecond)=0.1(sec)-->1/0.1= 10Hz
pause 100

[astanapane]

Dear all,

i need you help.

After removing all the DEFINEs and use only the following

'RCSTA2 = $90 ' Enable serial port & continuous receive
'TXSTA2 = $24 ' Enable transmit, BRGH = 1
'DEFINE HSER_CLROERR2 1 ' Clear overflow automatically
'SPBRG2 = 130 ' 9600 Baud @ 64MHz, -0,02%
'SPBRGH2 = 6
'BAUDCON2.3 = 1         ' Enable 16 bit baudrate generator

and for changing the baudrate and the frequency for the Second Serial,

pause 800 
HSEROUT2 ["$PMTK251,38400*27",13,10]      ' 38400 boundrate, check MTK manual configuration
pause 800

SPBRG2 = 160 ' 38400 Baud @ 64MHz, -0,08%
SPBRGH2 = 1
Pause 500

;HSEROUT2 ["$PMTK314,0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0*29",13,10]
HSEROUT2  ["$PMTK314,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28",13,10]
pause 100

HSEROUT2 ["$PMTK220,100*2F",13,10]        ' 100(millisecond)=0.1(sec)-->1/0.1= 10Hz
pause 100

I found out that on SERIAL TERMINAL on the computer of course i see the data coming from the GPS but unfortunately when i connect an LCD to PIC using the first Serial, the data cannot be displayed.

It seems that when i use

HSERIN2[wait("$GPRMC")

the data cannot be read from the GPS to the RX of the PIC.

I tried to check if there is a problem with the LCD, but i can send text to the LCD.

I tried to check and use only the DEFINEs with 9600 because the default for the GPS is 9600 and it worked.

so when i do not use the defines, it looks like that RX port on the PIC doesnt work.

Could you please help?

[Ioannis]

I don't know about other members of the forum, but I got confused.

Best throw in both codes that work and don't work.

Do they compile OK?

Are you sure about your connections?

Ioannis

[astanapane]

Ioanni,

thanks for your reply.

The problem is when i use the code to change on the fly as of the guys on the forum advice, without using the "DEFINE" word.

So using the registers like in the following code:

'RCSTA2 = $90 ' Enable serial port & continuous receive
'TXSTA2 = $24 ' Enable transmit, BRGH = 1
'DEFINE HSER_CLROERR2 1 ' Clear overflow automatically
'SPBRG2 = 130 ' 9600 Baud @ 64MHz, -0,02%
'SPBRGH2 = 6
'BAUDCON2.3 = 1         ' Enable 16 bit baudrate generator

and later in order to change the baudrate i use the following:

pause 800 
HSEROUT2 ["$PMTK251,38400*27",13,10]      ' 38400 boundrate, check MTK manual configuration
pause 800

SPBRG2 = 160 ' 38400 Baud @ 64MHz, -0,08%
SPBRGH2 = 1
Pause 500

;HSEROUT2 ["$PMTK314,0,1,1,1,1,0,0,0,0,0,0,0,0,0,0,0,0,1,0*29",13,10]
HSEROUT2  ["$PMTK314,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28",13,10]
pause 100

HSEROUT2 ["$PMTK220,100*2F",13,10]        ' 100(millisecond)=0.1(sec)-->1/0.1= 10Hz
pause 100

The GPS gets the command and set correctly the new configuration.

So up to here we are fine. I checked this by using a Serial Terminal and i see that both Baudrate and frequency have changed.

That means that TX is working well, for the first command to the GPS

HSEROUT2 ["$PMTK251,38400*27",13,10]      ' 38400 boundrate, check MTK manual configuration
pause 800

and changing on the fly the Baudrate the following command to GPS is working fine as well with the NEW baudrate.

HSEROUT2  ["$PMTK314,0,1,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0*28",13,10]
pause 100

HSEROUT2 ["$PMTK220,100*2F",13,10]        ' 100(millisecond)=0.1(sec)-->1/0.1= 10Hz
pause 100

[/CODE]

Now what is the problem.

I used a uLCD to send the VTG and RCM data to the display as i have done in the past using both SEROUT and HSEROUT2 command (for the HSEROUT2 i used the following code with the "DEFINE" and worked well)

'DEFINE HSER2_RCSTA 90h ' Enable serial port & continuous receive
        'DEFINE HSER2_TXSTA 24h ' Enable transmit, BRGH = 1
        'DEFINE HSER2_CLROERR 1 ' Clear overflow automatically
        'DEFINE HSER2_SPBRG 130 ' 9600 Baud @ 64MHz, -0,02%
        'SPBRGH2 = 6
        'BAUDCON2.3 = 1         ' Enable 16 bit baudrate generator

Now using the registers without the "DEFINEs" the RX on the PIC seems that it doesnt work, something like it is closed or cannot read data from GPS.

Forgot to mention that 2 hours now i have tried most of the different settings for the

BAUDCON2 = %xxxxxxxx

without any luck.

[astanapane]

Compile is ok, the same circuit as when the code is working with the "DEFINE" code.

Something is wrong with the new code that i change the baudrate on the fly.

there is something going really wrong. Maybe i need to give more PAUSE time?

I try that as well.

[Ioannis]

Page 281 of the K22 PIC has all the settings of the BRGH, BRG16, SPBRGx in relation to the system Clock.

Also, depending whether you have RS232 driver or not you have to set or reset the BAUDCONx bits 4 and 5.

If you will use on both Rx and Tx pins a driver (like the MAX232) then these bits should be 0. If you connect directly to another TTL serial port then these bits should be 1.

Ioannis