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PeWa
Joined: 15 Jan 2019
Posts: 22
Location: Sweden
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| Change PIN at Runtime |
 Posted: Sat Nov 27, 2021 5:02 am |
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In many examples we can use for example a #Define Pin_to_Use PIN_D1.
This is used when compiler generate the code.
However I have seen an example of change the PIN in runtime like this:
| Code: |
int16 pin_to_use;
pin_to_use=PIN_B0;
output_low(pin_to_use);
pin_to_use=PIN_B1;
output_low(pin_to_use);
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But this does not work in my case so I wonder what can go wrong with this type of code in CCS ? It compiles OK but the I/O address is wrong not point to the address defined in header file for the MCU.
Are there other ways to alter the PIN in an output_high(PIN_xx) at runtime maybe ?
I use compiler 5.076 and MCU is a 30F5011. |
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PeWa
Joined: 15 Jan 2019
Posts: 22
Location: Sweden
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| Re: Change PIN at Runtime |
| Posted: Sat Nov 27, 2021 8:43 am |
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| PeWa wrote: | In many examples we can use for example a #Define Pin_to_Use PIN_D1.
This is used when compiler generate the code.
However I have seen an example of change the PIN in runtime like this:
| Code: |
int16 pin_to_use;
pin_to_use=PIN_B0;
output_low(pin_to_use);
pin_to_use=PIN_B1;
output_low(pin_to_use);
|
But this does not work in my case so I wonder what can go wrong with this type of code in CCS ? It compiles OK but the I/O address is wrong not point to the address defined in header file for the MCU.
Are there other ways to alter the PIN in an output_high(PIN_xx) at runtime maybe ?
I use compiler 5.076 and MCU is a 30F5011. |
Edited, the variable address is OK. I can change a static LED but it seems that when I change to variable the output / input functions take some more time to compute. Is that the case ?? |
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temtronic
Joined: 01 Jul 2010
Posts: 9427
Location: Greensville,Ontario
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| Posted: Sat Nov 27, 2021 8:55 am |
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doing it as shown ,will require time to get the desired pin and insert into the output function
why not just ...
#DEFINE this_pin PIN_B2;
#DEFINE that_pin PIN_B4;
...
...
output_low(this_pin);
output_low(that_pin);
...
...
it 'should be faster'..... |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Re: Change PIN at Runtime |
| Posted: Sat Nov 27, 2021 9:23 am |
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| PeWa wrote: |
It seems that when I change to variable the output / input functions take some more time to compute. Is that the case ?? |
See this post. It shows how much ASM code is required if you use
a variable to pass the CCS pin number.
http://www.ccsinfo.com/forum/viewtopic.php?t=36953&start=3 |
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bkamen
Joined: 07 Jan 2004
Posts: 1615
Location: Central Illinois, USA
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| Posted: Fri Dec 03, 2021 2:29 am |
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You can also use the get_env for the PORT and LAT register addresses.
Then build a struct as you like with a default set of values.
Then just write those values to PORT/LAT registers on start up.
You end up configuring an entire register with a single write.
I'd have to go look at an old example to see how much ASM results.... but it should be pretty thin.
_________________
Dazed and confused? I don't think so. Just "plain lost" will do. :D |
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