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hugo_br
Joined: 01 Aug 2011
Posts: 26
Location: BRAZIL
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| Problem with Serial(RS232) in PIC24HJ128GP204! |
 Posted: Mon Aug 15, 2011 4:25 pm |
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Good evening everyone.
I'm having problems with the RS232 in PIC24HJ128GP204.
I can not get anything, much less so to send the serial of the PIC.
Below is a piece of source code.
I appreciate if you could give a help in some way.
| Code: |
#fuses hs, ec, nooscio, wrtb, nobss, norbs, nowdt, wposts1, wpres128, windis, noput, icsp1, alti2c, nojtag, nodebug, wrtss, nosss, norss, protect, nocksfsm, noiol1way, noieso
#use delay(clock=32000000, RESTART_WDT)
#pin_select U1TX = PIN_B10
#pin_select U1RX = PIN_C9
#use rs232(UART1,baud=115200,bits=8,parity=N,stop=1,stream=rs)
void main()
{
setup_adc_ports (sAN0 | sAN1 | VSS_VDD);
setup_adc (ADC_CLOCK_DIV_64);
set_tris_a(0x7ff);
set_tris_b(0x9203);
set_tris_c(0x2c0);
enable_interrupts(INTR_GLOBAL);
loop:
while(TRUE)
{
if (!input(S1))
{
printf("Start\r\n");
or
fprintf(rs,"Start\r\n");
PIC does not transmit anything!
}
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temtronic
Joined: 01 Jul 2010
Posts: 9229
Location: Greensville,Ontario
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| Posted: Mon Aug 15, 2011 4:50 pm |
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While I don't use that PIC some quick comments...
Always add 'errors' to the use rs232(options...)...
Never use set_tris()..... functions,let the compiler do it automatically for you.There's no need to manually code them and if you get 1 bit wrong...your program will fail...
you may have a wrong fuse selected,check each one,maybe compare to known working code ?
you have interrupts enabled but NO ISRs ! major mistake !! Either disable ALL ISRs or create ISR routines.
hopefully this may help you |
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hugo_br
Joined: 01 Aug 2011
Posts: 26
Location: BRAZIL
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| Posted: Tue Aug 16, 2011 8:52 am |
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I managed to run the serial communication with speeds up to 4800 but if I put values above this speed RS232 sends wrong characters.
I changed the line of fuses and TRIS to work at these speeds and disable interrupts as suggested by temtronic.
I do not know if there's something there, but I will be replacing the 32MHz oscillator with a 40MHz, does that help anything?
I keep waiting for the help everyone.
Good day anda thanks! |
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temtronic
Joined: 01 Jul 2010
Posts: 9229
Location: Greensville,Ontario
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| Posted: Tue Aug 16, 2011 11:26 am |
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Ok..first I'd add a delay in 'main' to space out the printing. right now it's a continous stream of data to, I assume, a PC with some kind of RS232 monitoring program.
Do you have a MAX232 type chip (I'll assume yes, as you say it works < 4800 baud).
Is the PC side a real rs232 comport or a USB dongle ?
Confirm the PC program will run at >4800 baud using a 'loopback' connector.
Proper wiring ( good ground) betwwen the two computers ?
Running out of straws to pull !! |
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hugo_br
Joined: 01 Aug 2011
Posts: 26
Location: BRAZIL
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| Posted: Wed Aug 17, 2011 8:50 am |
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I would like to thank everyone's help.
Problem solved!
Gotta run to 115200 with no problems.
I got it hitting the fuses and routines in the program.
On another board I will work a maximum in 2400, is a hardware limitation.
I isolate the line of communication with photo coupler so that the speed was affected. to maintain good communication went down to 1200, so the line is stable.
Now I need to do a routine to receive complete sentences with the PIC and not just a character. Does anyone have any suggestions for how to start?
Once again I thank everyone's attention.
Hugo. |
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