Yes, that's what I meant when I said that you may miss the actual pulse.
What about the following approach:
beginBatch();
sendPulse();
endBatch();
while (true) {
float duration = pulseIn.GetDurationBuffered();
if (duration > MIN_DURATION) return duration;
}
Of course, you can timeout if you want.
With this approach, every pulse is captured and considered, and you're
filtering out the really short ones that indicate the input pulses.
BTW, there are equivalent ultrasonic range finders that have a more
pleasant interface (for example, analog, or similar to the one you have but
the feedback is on a separate pin). Here's one (available on DX for <$5):
http://www.micropik.com/PDF/HCSR04.pdf
On Tue, Apr 15, 2014 at 7:00 PM, Vic Wintriss <[email protected]>wrote:
> Ytai:
>
> With the sync() call after the endBatch() and before the getDuration() the
> program hangs up and I get no readings.
>
> Vic
>
> On Apr 15, 2014, at 5:32 PM, Ytai Ben-Tsvi <[email protected]> wrote:
>
> This code doesn't have the sync() call I proposed. It should come after
> the batch.
> On Apr 15, 2014 4:43 PM, "Vic Wintriss" <[email protected]> wrote:
>
>> Ytai:
>>
>> This code produces only 1.6875E-5…reading 2 times per second.
>>
>> import ioio.lib.api.DigitalOutput;
>> import ioio.lib.api.IOIO;
>> import ioio.lib.api.PulseInput;
>> import ioio.lib.api.PulseInput.PulseMode;
>> import ioio.lib.api.exception.ConnectionLostException;
>>
>> public class UltraSonicSensors
>> {
>> private static final int LEFT_ULTRASONIC_INPUT_PIN = 35;
>> private static final int LEFT_STROBE_ULTRASONIC_OUTPUT_PIN = 15;
>> private final PulseInput leftInput;
>> private DigitalOutput leftStrobe;
>> private float leftDistance;
>> private IOIO ioio;
>> public UltraSonicSensors(IOIO ioio) throws ConnectionLostException
>> {
>> this.leftInput = ioio.openPulseInput(LEFT_ULTRASONIC_INPUT_PIN,
>> PulseMode.POSITIVE);
>> this.leftStrobe =
>> ioio.openDigitalOutput(LEFT_STROBE_ULTRASONIC_OUTPUT_PIN);
>> this.ioio = ioio;
>> }
>>
>> public void read() throws ConnectionLostException, InterruptedException
>> {
>> read(leftStrobe, leftInput);
>> }
>>
>> private void read(DigitalOutput strobe, PulseInput input) throws
>> ConnectionLostException, InterruptedException
>> {
>> ioio.beginBatch();
>> strobe.write(true);
>> strobe.write(false);
>> ioio.endBatch();
>> this.leftDistance = input.getDurationSync();
>> }
>>
>> public float getLeftDistance()
>> {
>> return leftDistance;
>> }
>> }
>> On Apr 15, 2014, at 4:27 PM, Ytai Ben-Tsvi <[email protected]> wrote:
>>
>> Can you send me the most "correct" version of your code that demonstrates
>> the issue?
>> I can probably make the necessary changes to sync () if this is indeed a
>> problem.
>> On Apr 15, 2014 4:03 PM, "Vic Wintriss" <[email protected]> wrote:
>>
>>> Thanks for the ideas. I've tried many combinations of synch,
>>> readBuffered...etc, but unfortunately it still reads very small
>>> numbers...probably measuring the last part of the trigger pulse. Is there
>>> any way that I can delay the read by a couple of hundred micro seconds?
>>> Could you do the..... sync() call "send" half inside the batch and "wait"
>>> half outside thing?
>>>
>>> Thanks for all the help. The kids are trying to use these sensors for
>>> iARoC 2014 (the International Autonomous Robot Competition) here in San
>>> Diego.
>>>
>>> --
>>> You received this message because you are subscribed to the Google
>>> Groups "ioio-users" group.
>>> To unsubscribe from this group and stop receiving emails from it, send
>>> an email to [email protected].
>>> To post to this group, send email to [email protected].
>>> Visit this group at http://groups.google.com/group/ioio-users.
>>> For more options, visit https://groups.google.com/d/optout.
>>>
>>
>> --
>> You received this message because you are subscribed to a topic in the
>> Google Groups "ioio-users" group.
>> To unsubscribe from this topic, visit
>> https://groups.google.com/d/topic/ioio-users/3MDLEEKtejY/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to
>> [email protected].
>> To post to this group, send email to [email protected].
>> Visit this group at http://groups.google.com/group/ioio-users.
>> For more options, visit https://groups.google.com/d/optout.
>>
>>
>>
>> --
>> You received this message because you are subscribed to the Google Groups
>> "ioio-users" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to [email protected].
>> To post to this group, send email to [email protected].
>> Visit this group at http://groups.google.com/group/ioio-users.
>> For more options, visit https://groups.google.com/d/optout.
>>
>
> --
> You received this message because you are subscribed to a topic in the
> Google Groups "ioio-users" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/ioio-users/3MDLEEKtejY/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> [email protected].
> To post to this group, send email to [email protected].
> Visit this group at http://groups.google.com/group/ioio-users.
> For more options, visit https://groups.google.com/d/optout.
>
>
> --
> You received this message because you are subscribed to the Google Groups
> "ioio-users" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to [email protected].
> To post to this group, send email to [email protected].
> Visit this group at http://groups.google.com/group/ioio-users.
> For more options, visit https://groups.google.com/d/optout.
>
--
You received this message because you are subscribed to the Google Groups
"ioio-users" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/ioio-users.
For more options, visit https://groups.google.com/d/optout.
