I've got my hardware all set and working, but I'm getting a pretty horrible lag behavior when I cat AIN files and I don't fully understand why. My testing set up is a cheapo IR range sensor connected to AIN5. I can distinguish between "point blank" and "out of range" very reliably, but when I transition between the two it reports the old value the first time I cat the file:
# cat AIN5 (with sensor uncovered, pointed out of range) 1795 # cat AIN5 (with finger covering the sensor) 1795 # cat AIN5 (with finger still covering the sensor) 232 # cat AIN5 (with sensor uncovered, pointing out of range) 219 # cat AIN5 (with sensor still uncovered) 1794 # cat AIN5 (with sensor still uncovered) 1795 ... Any idea why this is happening? I can reproduce the same behavior using Adafruit's Python library. More to the point, if I'm going to be using the AIN as the input to a control loop, what's the lowest latency way to do so? Is there any way to avoid having to reopen a file descriptor each time? I'd much rather just open a stream and go. --M@ -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
