On Sun, 16 Nov 2008 16:22:46 +0700 Sean McNeil <[EMAIL PROTECTED]> wrote:
> > But if that's true and this window exists I can't see how we could > > reduce the window to actually zero length by looping in the ISR, > > whatever opens and closes that window (eg, "being in an ISR") is > > not an atomic action. The new sample interrupt can still happen > > just after the last time we poll for it and get a negative response. > > But thats OK because if we loop until the line toggles then we will > get another edge interrupt. The problem is that we aren't really > clearing out the cause of the interrupt in the ISR. Well, stable-tracking uses your level-triggered interrupts anyway so I don't think this should be a problem anymore (however the chip actually work) :-) One difference I saw compared to the edge-triggered ones was that with a very small threshold, interrupts get generated at a very high rate which causes considerable slow-down (almost to a halt). With data-ready interrupts it's not so. I therefore raised the lowest threshold to avoid this particular problem - the lowest are not very useful anyway since the device continuously generates data even being stationary on a table. // Simon
