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Message |
richi-d
Joined: 28 Aug 2007
Posts: 106
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| Measurement of pulsewidth at 10 ports |
 Posted: Thu Aug 30, 2007 3:22 am |
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I need to measure the pulsewith at 10 ports. I can do it for every single pin, but is there a better method to do it with a for()?
Example: while ( !input(EINGANG_i_1) ) (I know this won´t work, but you see what i mean...)
Here is the code for the single pin measurement:
| Code: |
#define EINGANG_1_1 PIN_A4
#define EINGANG_2_1 PIN_A5
#define EINGANG_1_2 PIN_F2
#define EINGANG_2_2 PIN_F3
#define EINGANG_3_2 PIN_F4
#define EINGANG_4_2 PIN_F5
#define EINGANG_1_3 PIN_E0
#define EINGANG_2_3 PIN_E1
#define EINGANG_3_3 PIN_E2
#define EINGANG_4_3 PIN_E3
long IMPULSBREITE_[10];
void Komplettmessung (void)
{
long WERT_[2];
//PIN 1 /////////////////////////////////////////////////////////////////////////////
WERT_[1] = 1;
WERT_[2] = 0;
while ( WERT_[1] != WERT_[2] )
{
for (t=0; t<2; ++t)
{
while ( !input(EINGANG_1_1) )
{
NOP;
}
SET_TIMER1(0);
while ( input(EINGANG_1_1) )
{
NOP;
}
WERT_[t] = GET_TIMER1
}
}
IMPULSBREITE_[1] = WERT_[1];
//PIN 2 /////////////////////////////////////////////////////////////////////////////
WERT_[1] = 1;
WERT_[2] = 0;
while ( WERT_[1] != WERT_[2] )
{
for (t=0; t<2; ++t)
{
while ( !input(EINGANG_2_1) )
{
NOP;
}
SET_TIMER1(0);
while ( input(EINGANG_2_1) )
{
NOP;
}
WERT_[t] = GET_TIMER1
}
}
IMPULSBREITE_[2] = WERT_[1];
to be continued.....
} |
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richi-d
Joined: 28 Aug 2007
Posts: 106
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| Posted: Fri Aug 31, 2007 9:55 am |
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| Any ideas? I´m sure CCS has a solution... |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Fri Aug 31, 2007 10:33 am |
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If you ask a design question like this, you need to give us information
on the input signals and other issues:
What is the frequency of the input signals ?
Are they synchronous ? If so, on what edge ?
What is the expected range of the duty cycle ?
What accuracy is required in the pulse width determination ?
What PIC are you using ?
What is the oscillator frequency of the PIC ? |
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mskala
Joined: 06 Mar 2007
Posts: 100
Location: Massachusetts, USA
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| Posted: Fri Aug 31, 2007 11:48 am |
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| Look in the devices directory for your pic's .h file. In it they define all the PIN_A0, PIN_A1, ... names as numbers. It won't be understandable code, but you can use those numbers, either in a FOR loop if all pins happen to be sequential, or call a single routine with the pin number as parameter. |
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Guest
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| Posted: Mon Sep 03, 2007 1:24 am |
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Hi,
frequency: 50Hz
Synchron: no
duty cycle: 16ms low, 500ms - 2500ms high
acuracy: max. at 16MHz 0,25µs - a little offset doesn´t matter
Pic 18F452
Osc.: 16MHz
@mskala: I found the numbers in the .h file. Can I renumber them from 0- .... ? |
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richi-d
Joined: 28 Aug 2007
Posts: 106
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| Posted: Mon Sep 03, 2007 1:26 am |
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Hi,
frequency: 50Hz
Synchron: no
duty cycle: 16ms low, 500µs - 2500µs high
acuracy: max. at 16MHz 0,25µs - a little offset doesn´t matter
Pic 18F452
Osc.: 16MHz
@mskala: I found the numbers in the .h file. Can I renumber them from 0- .... ?
Sorry for double post - wrong pulsetime. They are from a receiver |
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richi-d
Joined: 28 Aug 2007
Posts: 106
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| Posted: Tue Sep 04, 2007 2:34 am |
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Thanks for the Tip with the numbers, it would work. But how can I change this numbers that they are all in a row?
For Exampe I want PIN_A0, PIN_A1, PIN_B3, PIN_B4, PIN_C5 and so on in a row:
| Code: | #define PIN_A0 31744
#define PIN_A1 31745
#define PIN_A2 31746
#define PIN_A3 31747
#define PIN_A4 31748
#define PIN_A5 31749
#define PIN_A6 31750
#define PIN_A7 31751
#define PIN_B0 31752
#define PIN_B1 31753
#define PIN_B2 31754
#define PIN_B3 31755
#define PIN_B4 31756
#define PIN_B5 31757
#define PIN_B6 31758
#define PIN_B7 31759
#define PIN_C0 31760
#define PIN_C1 31761
#define PIN_C2 31762
#define PIN_C3 31763
#define PIN_C4 31764
#define PIN_C5 31765
#define PIN_C6 31766
#define PIN_C7 31767 |
better would be for me:
| Code: | #define PIN_A0 32000
#define PIN_A1 32001//canged
#define PIN_A2 31746
#define PIN_A3 31747
#define PIN_A4 31748
#define PIN_A5 31749
#define PIN_A6 31750
#define PIN_A7 31751
#define PIN_B0 32002//canged
#define PIN_B1 32003//canged
#define PIN_B2 31754
#define PIN_B3 31755
#define PIN_B4 31756
#define PIN_B5 31757
#define PIN_B6 31758
#define PIN_B7 31759
#define PIN_C0 31760
#define PIN_C1 31761
#define PIN_C2 31762
#define PIN_C3 31763
#define PIN_C4 31764
#define PIN_C5 32004//canged
#define PIN_C6 31766
#define PIN_C7 31767 |
is this possible? I tried to simulate but it don´t work. Where do this numbers come from-where are the defined? |
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Ttelmah
Guest
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| Posted: Tue Sep 04, 2007 2:46 am |
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The numbers, are the memory address where the port is mapped, and the bit number _in_ this address, coded as address*8+bit_number.
These are set by the hardware of the chip. You cannot change them.
However consider a look_up table.
| Code: |
int16 port_to_use[] = {
PIN_A0, PIN_A1, PIN_B3, PIN_B4, PIN_C5
};
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Obviously with all the entries you want, in the order you want them.
Then to access the first port, just use:
output_high(port_to_use[0]);
Using a variable like this, will only work with the V4 compiler. However coe has been posted here in the past by a number of people (myself included), to give this behaviour with the old compiler.
Best Wishes |
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richi-d
Joined: 28 Aug 2007
Posts: 106
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| Posted: Tue Sep 04, 2007 4:49 am |
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| Perfect!! Thanks a lot... |
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