Re: [uCsimm] bogus interrupts on IRQ3?

From: daniel.haensse@fhk.usz.ch
Date: Mon Sep 03 2001 - 10:30:00 EDT


Did you use ethernet at that time? It is on irq 5!! Maybe if you're working with
heavy traffic this may be enough to make some pulses missing.
Try to toggle an output, when the interrupt service routine is executing and
compare the two traces.

Why don't you use a FPGA to count the pulses? I guess you will run into trouble
if you have more then 500Hz irq frequency. A FPGA would be easy to
be read every second to find out the distance. The way to interface the FPGA
you can find at www.openhardware.net/Dragonix/index.php.

Dani

Am Mon, 03 Sep 2001 schrieben Sie:
> Daniel Haensse wrote:
> >
> > How many interrupts do you get per second and how is the waveform of the
> > interrupt signal?
>
> Very little interrupts. 16 per wheel revolution, so it depends
> on how fast I spin the wheel.
>
> But even at a pulse per second, I sometimes get spurious interrupts.
> But only for PD6 (IRQ3), not PD7 (IRQ6)
>
> The signal on PD6 and PD7 is a simple blockwave, with sharp edges.
> The sensor has hysteresis, so no fast hi/lo switches near the
> transition area.
>
>
> >
> > Dani
> >
> > Am Son, 02 Sep 2001 schrieben Sie:
> > > Hello,
> > >
> > >
> > > I've written a device driver for my odometer on my robot.
> > > Basically, it needs to count pulses on PD6 and PD7.
> > >
> > > PD6 uses IRQ3,
> > > PD7 uses IRQ6.
> > >
> > > For IRQ3, I sometimes get interrupts, but when checking
> > > the ISR, the corresponding bit is not set.
> > >
> > > Where do these fantom interrupts come from?
> > > In /proc, I can see:
> > >
> > > /proc> cat interrupts
> > > Internal 68EZ328 interrupts
> > > 1: 29091 timer
> > > 2: 603 M68328_UART
> > > 18: 63 odometer1
> > > 19: 25 odometer0
> > > 20: 543 eth0
> > >
> > >
> > > So I do not think that interrupt 18 and 19 are used for anything else.
> > > IRQ6 looks cleaner: I only get proper interrupts for that one.
> > >
> > > Bram
> > >
> > > --
> > > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
> > > Bram Stolk "Your mouse has moved. Windows must be restarted for the
> > > bram.s@chello.nl change to take effect. Reboot now?"
> > >
> > >
> > > This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/
> > This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/
> This message resent by the ucsimm@uclinux.com list server http://www.uClinux.com/
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