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haxan7
Joined: 27 Jul 2013
Posts: 79
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| How to #define a Pre-Processor directive? |
 Posted: Fri Dec 26, 2014 2:06 am |
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How to I #define a Pre-Processor directive? I want this so that I can easily move devices between UART Ports.
I want something like this:
| Code: |
#define device2ISR INT_RDA3
#device2ISR
void myISR(){
//...
//...
}
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dyeatman
Joined: 06 Sep 2003
Posts: 1924
Location: Norman, OK
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| Posted: Fri Dec 26, 2014 9:07 am |
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...
Last edited by dyeatman on Fri Dec 26, 2014 4:29 pm; edited 3 times in total |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19369
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| Posted: Fri Dec 26, 2014 9:31 am |
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He wants to dynamically change things.
The only way I can think of to do this easily, would be with a 'hybrid' approach.
Problem is that you need to change so many things (not just the ISR, but the interrupt enable, and the character I/O functions)....
So, take advantage of the new compilers abilities to handle the ISR for you. Don't have an INT_RDAx or INT_TBEx, but use the buffer implementation in #USE_RS232, with interrupt support. Then you can just change this function to talk to whatever UART you want. It'll automatically shift the ISR's to suit.
Look here for the 'limitations' of this implementation (primary one if handling of buffer overflow), but it does seem to work correctly, provided this is avoided.
The only other way would be using #ifdef and a UART number, to deselect/select the required routines. |
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haxan7
Joined: 27 Jul 2013
Posts: 79
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| Posted: Sat Dec 27, 2014 9:46 am |
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Thanks for the replies.
I am doing it like following:
| Code: |
#if MY_DEVICE_STREAM==UART_PORT1
#define MY_DEVICE_RDA INT_RDA
#INT_RDA
#ELIF MY_DEVICE_STREAM==UART_PORT2
#define MY_DEVICE_RDA INT_RDA2
#INT_RDA2
#ELIF MY_DEVICE_STREAM==UART_PORT3
#define MY_DEVICE_RDA INT_RDA3
#INT_RDA3
#ELIF MY_DEVICE_STREAM==UART_PORT4
#define MY_DEVICE_RDA INT_RDA4
#INT_RDA4
#endif
void myISR(){
char c = fgetc(MY_DEVICE_STREAM);
}
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Ttelmah
Joined: 11 Mar 2010
Posts: 19369
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| Posted: Sat Dec 27, 2014 10:24 am |
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You still have to change the interrupt enable as well.
Your approach seems pointless, since you are not adding buffering (just one character). Why not use the internal buffering?. Easier, and safer
Just specify something like 8 characters of buffering in your #use RS232, and tell it to use interrupts, and get rid of your interrupt handler completely. Whenever kbhit says there is a character, something is in the buffer waiting for you. |
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haxan7
Joined: 27 Jul 2013
Posts: 79
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| Posted: Sat Dec 27, 2014 10:32 am |
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| Ttelmah wrote: | You still have to change the interrupt enable as well.
Your approach seems pointless, since you are not adding buffering (just one character). Why not use the internal buffering?. Easier, and safer
Just specify something like 8 characters of buffering in your #use RS232, and tell it to use interrupts, and get rid of your interrupt handler completely. Whenever kbhit says there is a character, something is in the buffer waiting for you. |
I can enable/disable the interrupts using MY_DEVICE_RDA, which I have defined above.
ISR in my post above is just an example, actual ISR is much complex. |
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temtronic
Joined: 01 Jul 2010
Posts: 9174
Location: Greensville,Ontario
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| Posted: Sat Dec 27, 2014 11:03 am |
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I'm lost trying to understand what you're trying to accomplish. It's an easy task to setup 4 ISRs for the 4 hardware UARTs your PIC has(very,very few have 4 UARTs !).What PIC are you using??
Using the CCS supplied ex_sisr.c example, it can be expanded to include all 4 .
Perhaps you can explain in better detail what you need to accomplish?
I'm thinking there's a far easier solution !!
jay |
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haxan7
Joined: 27 Jul 2013
Posts: 79
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| Posted: Sat Dec 27, 2014 11:10 am |
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| temtronic wrote: | I'm lost trying to understand what you're trying to accomplish. It's an easy task to setup 4 ISRs for the 4 hardware UARTs your PIC has(very,very few have 4 UARTs !).What PIC are you using??
Using the CCS supplied ex_sisr.c example, it can be expanded to include all 4 .
Perhaps you can explain in better detail what you need to accomplish?
I'm thinking there's a far easier solution !!
jay |
I have a bunch of devices, of which 4 will be connected to the uController.
ISR of each device is unique that looks for bit patterns and # of bits etc and sets a flag.
I wanted a way so that the devices can be easily selected on specified port. |
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Ttelmah
Joined: 11 Mar 2010
Posts: 19369
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| Posted: Sat Dec 27, 2014 11:20 am |
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| haxan7 wrote: | | Ttelmah wrote: | You still have to change the interrupt enable as well.
Your approach seems pointless, since you are not adding buffering (just one character). Why not use the internal buffering?. Easier, and safer
Just specify something like 8 characters of buffering in your #use RS232, and tell it to use interrupts, and get rid of your interrupt handler completely. Whenever kbhit says there is a character, something is in the buffer waiting for you. |
I can enable/disable the interrupts using MY_DEVICE_RDA, which I have defined above.
ISR in my post above is just an example, actual ISR is much complex. |
Except for buffering, it shouldn't be.
Rule with ISR's is always get out ASAP. Simple buffering is all that should be done in a serial ISR. |
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Eugeneo
Joined: 30 Aug 2005
Posts: 155
Location: Calgary, AB
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| Posted: Wed Dec 31, 2014 1:55 pm |
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You could do this:
#define MY_DEVICE_STREAM1 UART_PORT4
#define MY_DEVICE_STREAM2 UART_PORT3
| Code: |
#if MY_DEVICE_STREAM1==UART_PORT1
#INT_RDA
#ELIF MY_DEVICE_STREAM1==UART_PORT2
#INT_RDA2
#ELIF MY_DEVICE_STREAM1==UART_PORT3
#INT_RDA3
#ELIF MY_DEVICE_STREAM1==UART_PORT4
#INT_RDA4
#endif
void RDA_STREAM1(){
char c = fgetc(MY_DEVICE_STREAM1);
}
#if MY_DEVICE_STREAM2==UART_PORT1
#INT_RDA
#ELIF MY_DEVICE_STREAM2==UART_PORT2
#INT_RDA2
#ELIF MY_DEVICE_STREAM2==UART_PORT3
#INT_RDA3
#ELIF MY_DEVICE_STREAM2==UART_PORT4
#INT_RDA4
#endif
void RDA_STREAM2(){
char c = fgetc(MY_DEVICE_STREAM2);
}
.. and so forth
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temtronic
Joined: 01 Jul 2010
Posts: 9174
Location: Greensville,Ontario
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| Posted: Wed Dec 31, 2014 2:10 pm |
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re:
"
I have a bunch of devices, of which 4 will be connected to the uController.
ISR of each device is unique that looks for bit patterns and # of bits etc and sets a flag.
I wanted a way so that the devices can be easily selected on specified port.
"
...
Not to sure how you can accomplish that as hardware UARTS are setup for a fixed # of bits,baud,parity, etc. Even with 'streams' I don't see how you could detect unknown device #1 on serial input #3. Maybe I'm missing something?
Jay |
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Eugeneo
Joined: 30 Aug 2005
Posts: 155
Location: Calgary, AB
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| Posted: Wed Dec 31, 2014 2:41 pm |
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| temtronic wrote: | re:
"
I have a bunch of devices, of which 4 will be connected to the uController.
ISR of each device is unique that looks for bit patterns and # of bits etc and sets a flag.
I wanted a way so that the devices can be easily selected on specified port.
"
...
Not to sure how you can accomplish that as hardware UARTS are setup for a fixed # of bits,baud,parity, etc. Even with 'streams' I don't see how you could detect unknown device #1 on serial input #3. Maybe I'm missing something?
Jay |
I see what you mean. If you create a steam, only that function uses that stream. You would have to build all the different combinations of stream functions.
Can you not have a bunch of functions that all have different streams. Then call them to re-init the port and then use the new stream?
You can't pin_select after they have been assigned in CCS, but you can do it manually. So you can physically change the internal uart mapping. 
I'm not saying it's a good idea. It's just an idea.
it's not going to look pretty. |
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temtronic
Joined: 01 Jul 2010
Posts: 9174
Location: Greensville,Ontario
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| Posted: Wed Dec 31, 2014 3:43 pm |
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It'd be nice to know which PIC you're using as well as these 'devices' that get connected.
I have serious doubts you can attach a 'device' to the PIC and have the PIC figure out what the 'device' is unless you already know the 'datastream' coming from the device(which we don't). We don't know baud rates, bits per data, etc. all critical 'need to know' details.
jay |
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Eugeneo
Joined: 30 Aug 2005
Posts: 155
Location: Calgary, AB
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| Posted: Wed Dec 31, 2014 7:13 pm |
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| temtronic wrote: | It'd be nice to know which PIC you're using as well as these 'devices' that get connected.
I have serious doubts you can attach a 'device' to the PIC and have the PIC figure out what the 'device' is unless you already know the 'datastream' coming from the device(which we don't). We don't know baud rates, bits per data, etc. all critical 'need to know' details.
jay |
I'm using the PIC24FJ128GA306 connected to various serial devices.
Are you are talking about a plug and play serial host. May need a few bytes of free space to make that table.  |
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