can someone help me with RCTIME

[gandora]

I have been having problem getting RCTIME to work it always results in 1 even when nothing is connected to it. I have a feeling it has something to do with the way I have analog set up, but I haven't been able to figure it out.

the code for serial output and delays is working fine. but I just get a constant stream of 1's no matter what I do. If anyone could help it would be awesome!

'---clock settings
        define OSC 8
        OSCCON = %1111110 ' sets internal osc to run at 8MHZ

'----------turn analog on porta off, and use as digital input/output
        CMCON = 0 'Comparators ON (right?)
        ANSEL = 1 'A/D ON -- Port pins all analog (I hope)
'----------

'---** Constants

rcpin var porta.3

'---**variables

rcreturn var byte

'------**main program



loop:  

'----its rctime!
pause 1000

high rcpin
pause 5 
rctime rcpin,1,rcreturn
low rcpin


'----(end rctime) shows over folks ^^



'----send serial feedback      
        serout2 porta.0, 16468, ["rc time was: ",dec rcreturn] 'call for data    
 '-----end serial feedback

goto loop   'loop forever
end

[mackrackit]

RCTIME is a digital command. All it does is measure the time it takes to discharge a capacitor to a certain voltage.

Turn analog and comparators off for the pin you are using.

[mister_e]

Hi and Welcome on the forum,
Any specific reason why you want to use RcTime? What do you want to do?

[T.Jackson]

Gotta be a Time Machine. Just has to be. This would be about the only use for RCTIME.

[mister_e]

Could be, but why i'm asking is that many use RcTime to read a POT, while using the ADC is much efficient and don't need any extra capacitor.

Let's see...

[T.Jackson]

Yeah - RCTIME is a bit inadequate for that, there's not enough span at the lower end. I think min is a few KΩ. Besides, relatively inefficient too, tying up a complex protocol for something so simple.

[gandora]

Gotta be a Time Machine. Just has to be. This would be about the only use for RCTIME.

Im starting with the basics but you discovered my evil plan! ^^

[gandora]

well, as a clarification I forgot to include. I am using the 16f88 as this projects chip. And I am trying to read a photoresistor or a pot. Mostly I am trying to carry over my knowledge of electronics from the basic stamp. And make sure I know how to do everything I had learned up till' now.

If I can do that, I can still use the books I purchased for the basic stamp as a learning tool for the pic micro. As I have decided that the stamps are not cost effective, and want to learn at a little more depth.

Also as a note, I have attempted to get it to work all digital, and on digital only ports with the same result.

If there is a better way, do tell, however I still want to know how to get the command to work. ^^ thankyou.

Hi and Welcome on the forum,
Any specific reason why you want to use RcTime? What do you want to do?

[T.Jackson]

As pointed out earlier, RCTIME is a digital function not analog. So you'll need to enable the port in digital mode. Your code gears the port up in analog mode. BS2 is an unpopular joke in my opinion.

[gandora]

As pointed out earlier, RCTIME is a digital function not analog. So you'll need to enable the port in digital mode. Your code gears the port up in analog mode. BS2 is an unpopular joke in my opinion.

Alright Thankyou for your help i now got it to work. For other newbs who would prefer not make a fool of themselves. The working code is below.

Thanks again. it now results in different things depending on the light. ^^

'---clock settings
        define OSC 8
        OSCCON = %1111110 ' sets internal osc to run at 8MHZ

'----------turn analog on porta off, and use as digital input/output
        CMCON = 7 'Comparators off
        ANSEL = 0 'A/D off -- Port pins all digital
'----------^^^^^^^^^^
'----------the change is in this block of code

'---** Constants

rcpin var porta.3

'---**variables

rcreturn var byte

'------**main program



loop:  

'----its rctime!
pause 1000

high rcpin
pause 5 
rctime rcpin,1,rcreturn
low rcpin


'----(end rctime) shows over folks ^^



'----send serial feedback      
        serout2 porta.0, 16468, ["rc time was: ",dec rcreturn] 'call for data    
 '-----end serial feedback

goto loop   'loop forever
end

[mister_e]

BS2 is an unpopular joke in my opinion.

To me, ANY Basic Stamp are as good as PIC16F84

But come-on... 40$ EACH