FRC (Free running clock) in Revo

[zolt]

Can you, please, advice if Revo has FRC (free running clock) device or anything similar to the Serices 3a/3c have? Or how is it possible to mesure timing with high resolution in Revo. Thanks.

[brianh]

I am assuming that a "free running clock" is a stopwatch (forgive me if I am wrong). You should be able to fine stopwatch apps in the software section of PsionPlace or at Tucows - www.epocsoftware.com

Hope this helps.

[zolt]

Thanks for your reply. But unfortunatelly you understand me not correctly. In Series 3a/3c/3mx FRC (free running clock) is a dedicated chip which allows to measure timing with frequency up to 1/1024 of second. You can get results by accesing to this chip in OPL like IOOPEN(h%,"FRC:",-1) using name of device "FRC:". But it does not work for Revo in OPL32. So I am just wondering if there is other name for accessing this device, other ways to measure high frequence timing.

Thanks again for your reply. I hope still somebody can help me with this issue.

Max.

[ktkawabe]

Hi zolt,

There's no FRC on EPOC as far as I know, but of course you can use system clock chip. EPOC specification doesn't say anything about the resolution of these chips, but it seems that all Psion devices use the standard ones used in most of the PCs, i.e. 32.768kHz as the time base. This doesn't necessarily mean that you can measure time with 30 microsec resolution, though (see below).

From OPL, you can use the clock in two ways:

1. Use Date OPX. This is suitable for purposes that don't require any callback (i.e. suitable for measuring interval of the two events etc.). You can use DTNow&: function to capture the current time. See the OPL documentation for this. What is not written in the documentation is that your resolution is actually 512 clocks of the base (i.e. 15.625msec), at least on Series 5 and 5mx.

2. If you need a timer (i.e. a callback from the system after a given interval etc.), you have to use IO function call, passing "TIM:" as the device name. The following article in the Symbian knowledge base gives you some idea.
http://www3.symbian.com/faq.nsf/45aef46f9a8a61f9802569de0067eb63/9598377687cf366180256a570051b8b2?OpenDocument
In this case you pass the time value measured in 0.1 sec.

Hope this helps.
Regards,
Keita

P.S. to the moderators:
I think this thread is useful not only for Revo users but for anybody programming for EPOC devices. Isn't it worth moving this to Programming board?

Agreed and done! - netBookBabe