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doguhanpala
Joined: 05 Oct 2016
Posts: 120
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| defining software uart in function |
 Posted: Thu Apr 26, 2018 4:00 am |
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Hello everyone,
I am trying to define my software uart with parameters. However, there is a problem
I wrote this
| Code: |
int stepmotorID = 6;
switch(stepmotorID)
{
case 5: #use rs232(baud=9600, xmit=PIN_B2, stream=stepmodule) break;
case 6: #use rs232(baud=9600, xmit=PIN_B3, stream=stepmodule) break;
}
putc('1',stepmodule);
step_sayisi_l=200;
step_sayisi_h=0;
putc(step_sayisi_h,stepmodule);
delay_ms(1);
putc(step_sayisi_l,stepmodule);
delay_ms(5);
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The problem is weird. When i define stepmotorID as 6 it works. I change it to 5 and it stops working.
I believe there is a problem with ";" since i dont use with #use rs232 line.
Can the software uart be defined in function? If i have to define it at the beginning, can i enable and disable it during my code. I want to use the pins as I/O when they stop communicating.
Thank you very much! |
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doguhanpala
Joined: 05 Oct 2016
Posts: 120
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| Posted: Thu Apr 26, 2018 4:28 am |
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now things got more interesting
I edited my code to this.
| Code: | #include <18F4550.h>
#DEVICE ADC=10
#fuses HSPLL,NOWDT,MCLR,PROTECT,NOLVP,NODEBUG,NOBROWNOUT,USBDIV,PLL5,CPUDIV1,VREGEN
#use delay(clock=48000000)
#use rs232(baud=9600, UART,ERRORS,stream = bt)
void func();
void step();
int step_sayisi_l=200;
int step_sayisi_h=0;
int stepdriverport=0;
void main()
{
func();
}
void func()
{
delay_ms(1000);
stepdriverport=7;
if (stepdriverport == 5)
{
#use rs232(baud=9600, xmit=PIN_B2, stream=stepmodule)
step();
}
else if (stepdriverport == 6){
#use rs232(baud=9600, xmit=PIN_B3, stream=stepmodule)
step();
}
else if (stepdriverport == 7){
#use rs232(baud=9600, xmit=PIN_B4, stream=stepmodule)
step();
}
else if(stepdriverport==8)
{
#use rs232(baud=9600, xmit=PIN_B5, stream=stepmodule)
step();
}
}
void step()
{
putc('1',stepmodule);
step_sayisi_l=200;
step_sayisi_h=0;
putc(step_sayisi_h,stepmodule);
delay_ms(1);
putc(step_sayisi_l,stepmodule);
delay_ms(5);
} |
when i call the step function it does not work. However when i edit code to this uglier version, it starts to work. what could be the reason? Any ideas?
| Code: | if (stepdriverport == 5)
{
#use rs232(baud=9600, xmit=PIN_B2, stream=stepmodule)
putc('1',stepmodule);
step_sayisi_l=200;
step_sayisi_h=0;
putc(step_sayisi_h,stepmodule);
delay_ms(1);
putc(step_sayisi_l,stepmodule);
delay_ms(5);
}
else if (stepdriverport == 6){
#use rs232(baud=9600, xmit=PIN_B3, stream=stepmodule)
putc('1',stepmodule);
step_sayisi_l=200;
step_sayisi_h=0;
putc(step_sayisi_h,stepmodule);
delay_ms(1);
putc(step_sayisi_l,stepmodule);
delay_ms(5);
}
else if (stepdriverport == 7){
#use rs232(baud=9600, xmit=PIN_B4, stream=stepmodule)
putc('1',stepmodule);
step_sayisi_l=200;
step_sayisi_h=0;
putc(step_sayisi_h,stepmodule);
delay_ms(1);
putc(step_sayisi_l,stepmodule);
delay_ms(5);
}
else if(stepdriverport==8)
{
#use rs232(baud=9600, xmit=PIN_B5, stream=stepmodule)
putc('1',stepmodule);
step_sayisi_l=200;
step_sayisi_h=0;
putc(step_sayisi_h,stepmodule);
delay_ms(1);
putc(step_sayisi_l,stepmodule);
delay_ms(5);
}
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edit: i think i solved why this code works. the code goes into the if and after the #use rs232 line it sends the commands.
but in the first version, the code sees the last #use rs232 line which is
#use rs232(baud=9600, xmit=PIN_B5, stream=stepmodule)
since pin b5 is the software uart, pin b4 does not behave as uart. however i dont know how to disable the use rs232 lines that i dont use. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19545
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| Posted: Thu Apr 26, 2018 6:19 am |
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You need to understand, #use is a _preprocessor_ directive, not code.
To switch UART's in the function you just use the stream name, and select this with your switch.
| Code: |
#use rs232(baud=9600, xmit=PIN_B2, stream=stepmoduleB2)
#use rs232(baud=9600, xmit=PIN_B3, stream=stepmoduleB3)
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Then just select the stream name for fputc, between stepmoduleB2 and stepmoduleB3 |
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Fusillade
Joined: 02 Aug 2007
Posts: 31
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| Posted: Thu Apr 26, 2018 6:34 am |
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Explained here:
https://www.ccsinfo.com/faq.php?page=multiple_rs232
_________________
New:
Compiler Version: 5.078
IDE Version: MPLAB X V4.15
Devices: PIC18LF****
Old:
Compiler Version: 4.121
IDE Version: MPLAB IDE V8.63
Devices: PIC18LF**** |
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doguhanpala
Joined: 05 Oct 2016
Posts: 120
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| Posted: Thu Apr 26, 2018 7:47 am |
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| Ttelmah wrote: | You need to understand, #use is a _preprocessor_ directive, not code.
To switch UART's in the function you just use the stream name, and select this with your switch.
| Code: |
#use rs232(baud=9600, xmit=PIN_B2, stream=stepmoduleB2)
#use rs232(baud=9600, xmit=PIN_B3, stream=stepmoduleB3)
|
Then just select the stream name for fputc, between stepmoduleB2 and stepmoduleB3 |
thank you ttelmah
My intention was to choose the pin which will be used as softwareuart. As far as i understand you suggest i use multiple software uart and choose the which one i need. I have thought of it but did not want to because the code would be too long and i would have to write the putc functions for each uart.
I thought i could use a parameter to define uart.
I have one more question. I will use 6 software uarts for 6 pin. Also i want to use them as I/O's. Does defining a pin as uart affects usage as I/O ?
Thank you for your answer!
My best wishes
Doguhan |
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doguhanpala
Joined: 05 Oct 2016
Posts: 120
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| Posted: Thu Apr 26, 2018 7:48 am |
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thank you so much!
I did not want to use multiple uarts but it seems it is the only solution. |
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alan
Joined: 12 Nov 2012
Posts: 357
Location: South Africa
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| Posted: Thu Apr 26, 2018 7:58 am |
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| I don't know if this will work, but try #inline for your function and check the code generated. It might generate the correct code under each #use statement |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19545
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| Posted: Thu Apr 26, 2018 8:54 am |
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On software UART's the pins can still be used for normal I/O.
You need to understand that there is different code for each software UART. The compiler uses explicit bit set/test operations on the specific pin, so the code can't be 'switched'. The amount of code involved though is tiny. You can just encapsulate the output into a function (my_putc for example), which automatically routes to the required UART, then use this to take the output you want to send. |
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doguhanpala
Joined: 05 Oct 2016
Posts: 120
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| Posted: Sat Apr 28, 2018 3:23 am |
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| Ttelmah wrote: | On software UART's the pins can still be used for normal I/O.
You need to understand that there is different code for each software UART. The compiler uses explicit bit set/test operations on the specific pin, so the code can't be 'switched'. The amount of code involved though is tiny. You can just encapsulate the output into a function (my_putc for example), which automatically routes to the required UART, then use this to take the output you want to send. |
Thank you Ttelmah. I solved my problem, the code now chooses which pin to use from multiple rs232.
I have a tiny question. I tried the rs232 pin as output. It works fine. I blinked a led. After that i could not manage to use that pin as uart again.
for example
| Code: |
output_high(pin_b5);
delay_ms(100);
output_low(pin_b5);
delay_ms(10000);//in this 10 seconds i remove my led and put my step driver module
putc('1',stepmoduledriverP5); |
My guess is when the output is low the step module sees is as '0'. Is there a line of code that prepares the pin as uart again? I will put my module after that line of code. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19545
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| Posted: Sat Apr 28, 2018 12:51 pm |
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| Remember the serial expects the line to start 'high'. If you have set it low the first (start) bit won't be seen. It needs to be back high before the software UART can be used. |
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