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you are absolutely right, 1001 is what I get.
I am sorry if I ask again about the timing but are you able to explain this?
if I keep the timer running, I removed the PAUSEUS and I do something like this:
The first set of H/L I get 401Code:LCDOUT $FE,$80,"H",dec TMR1H,"L",dec TMR1L,"H",dec TMR1H,"L",dec TMR1L
The second set I get 4604
Why it isn't the second set taking arround 800?
Is it because the actual calculation is based on the assembly and when it is compiling it is doing funny things?
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Its possible that the LCDOUT routine really is taking that long.
But ive found that its generally best to stop the timer to take a reading, and usually best to store that reading in a variable before displaying it, or doing anything else with it.
See what happens if you do it like this:
temp VAR word
TMR1H=0 ' Reset timer value
TMR1L=0
T1CON.0=1 ' Start the timer
pauseus 1000
T1CON.0=0 ' Stop the timer
temp.HighByte=TMR1H
temp.LowByte=TMR1L
T1CON.0=1 ' Restart the timer
LCDOUT $FE,$80,"TMR1 = ", dec temp
T1CON.0=0 ' Stop the timer
temp.HighByte=TMR1H
temp.LowByte=TMR1L
LCDOUT $FE,$C0,"TMR1 = ", dec temp
The difference between the 2 results will tell you how long the first LCDOUT routine is taking.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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...well I am getting closer to the numbers I am expecting but...
My values were 1001 and 4206 so it took 3205 to perform LCDOUT.
Then I restarted the timer just before the last LCDOUT and added this to your code and got a value of 7405
T1CON.0=0 ' Stop the timer
temp.HighByte=TMR1H
temp.LowByte=TMR1L
LCDOUT $FE,$80,"TMR1 = ", dec temp
So the second time LCDOUT executed it took 3199
I did it a third time and found a different number again.
So LCDOUT executed 3 times and it took less time everytime it executed.
1st time took 3205
2nd time took 3199
3rd time took 3187
I figured writting to the LCD on a blank line took 3205
overwriting on the first line of the LCD took 3199
and overwritting on the second line took 3187
But I did it a fourth time (overwrote on the first line) and it took 3312
This is the code I ended up with:
This beeing said, if I start over from the begining, no matter how many times I am always getting the same results so this rules out a bad resonator or voltage noise or any othe hardware issue.Code:temp VAR word TMR1H=0 ' Reset timer value TMR1L=0 T1CON.0=1 ' Start the timer pauseus 1000 T1CON.0=0 ' Stop the timer temp.HighByte=TMR1H temp.LowByte=TMR1L T1CON.0=1 ' Restart the timer LCDOUT $FE,$80,"TMR1 = ", dec temp T1CON.0=0 ' Stop the timer temp.HighByte=TMR1H temp.LowByte=TMR1L T1CON.0=1 ' Restart the timer LCDOUT $FE,$C0,"TMR1 = ", dec temp T1CON.0=0 ' Stop the timer temp.HighByte=TMR1H temp.LowByte=TMR1L T1CON.0=1 ' Restart the timer LCDOUT $FE,$80,"TMR1 = ", dec temp T1CON.0=0 ' Stop the timer temp.HighByte=TMR1H temp.LowByte=TMR1L T1CON.0=1 ' Restart the timer LCDOUT $FE,$C0,"TMR1 = ", dec temp T1CON.0=0 ' Stop the timer temp.HighByte=TMR1H temp.LowByte=TMR1L LCDOUT $FE,$80,"TMR1 = ", dec temp
So there is something in the process that is hapenning which is irregular and I wish I could understand what it is!
I am really sorry to be such a pain and I appreciate your patience but I am still a little confused.
Mike
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lilimike, A answer to your question is in the delays you have programmed into the LCD DEFINES. Just look at what you have....
LCD_DATAUS CON 50 ' Data delay time in us
LCD_COMMANDUS CON 2000 ' Command delay time in us
Everytime you send a cursor command proceeded with $FE your code is waiting 2 milliseconds...
Dave Purola,
N8NTA
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Hi Dave,
This I can understand that the LCDOUT command is taking time to do what it has to do and it is configured with some delays but what i don't understand is why it is taking a different time each time I send data to LCDOUT.
(I've never wrote the word "time" so many times in so little time in my life)
Could it be that it is the LCD's controller itself that is taking a different time to generate different data?
Maybe it is faster to write 1 than 8?
Maybe I am trying to find the solution in the PIC process but the solution is actually in the LCD process?
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The difference between 3205, 3199, 3187 and 3312 is really not a lot when you think that this is measured in microseconds.
The command you are timing is this:
LCDOUT $FE,$80,"TMR1 = ", dec temp
The time this takes will depend on the value of temp. As temp increases, it takes longer to convert it into a decimal number (dec temp), and as the decimal number increases in number of digits, it takes slightly longer to write it to the screen.
What happens if you reset the timer value each time? Try adding TMR1H=0 and TMR1L=0 just before each time you start the timer.
"I think fish is nice, but then I think that rain is wet, so who am I to judge?" - Douglas Adams
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If I reset the timer I will obviously always get the same value because temp will always display the same value.
So I rewrote the code to this:
and I specified different values to display in staticVal.Code:staticVal var word temp VAR word TMR1H=0 ' Reset timer value TMR1L=0 T1CON.0=1 ' start the timer pauseus 1000 T1CON.0=0 ' Stop the timer staticVal = 70 T1CON.0=1 ' start the timer LCDOUT $FE,$80,"TMR1 = ", dec staticVal T1CON.0=0 ' Stop the timer temp.HighByte=TMR1H temp.LowByte=TMR1L LCDOUT $FE,$C0,"Disp Time = ", dec temp
It turns out that displaying 1 to 9 took 3819 ms
to display 10 to 29 and 40 to 49 took 3944 ms
to display 30 to 39 and 50 to 69 took 3938 ms
and so on...
So you are right, this confirms that the difference of time LCDOUT is taking to display is based on which value is beeing displayed. This makes me wonder because technically it is always computing 4 bit at a time but at least now I know what is going on and I thank you for your help and your patience.
Mike
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