I recently wanted to connect an 08M2 to the 1 second PPS output from an EN-406 GPS module. The high pulse is only 1uSec long so I thought I’d use the Timer1 Gate logic to latch the pulse as suggested by AllyCat in #10 of this thread.
However, it only seems to latch every second pulse (ie a 2 second interval in my case) and I wonder why? I initially assumed that it was something to do with the flip/flop controlled by T1GTM but that should be bypassed with Alan’s suggested value for T1GCON of $18. I tried various other values for T1GCON just to be sure but I couldn’t ever get it to latch successive pulses.
I hadn’t noticed this problem when I first tried out Alan’s suggestion some time ago but then I’d simply generated the pulse by touching a wire from pin C.4 to 5V to generate the pulse while the 08M2 was sleeping and it seemed to work perfectly. I suspect now that that may have been due to contact bounce generating more than 1 pulse.
I haven’t tried it with any other 08M2 but I have no reason to believe that this 08M2 is damaged in some way.
Has anyone else seen this problem?
However, it only seems to latch every second pulse (ie a 2 second interval in my case) and I wonder why? I initially assumed that it was something to do with the flip/flop controlled by T1GTM but that should be bypassed with Alan’s suggested value for T1GCON of $18. I tried various other values for T1GCON just to be sure but I couldn’t ever get it to latch successive pulses.
I hadn’t noticed this problem when I first tried out Alan’s suggestion some time ago but then I’d simply generated the pulse by touching a wire from pin C.4 to 5V to generate the pulse while the 08M2 was sleeping and it seemed to work perfectly. I suspect now that that may have been due to contact bounce generating more than 1 pulse.
I haven’t tried it with any other 08M2 but I have no reason to believe that this 08M2 is damaged in some way.
Has anyone else seen this problem?