From: Jonathan Cameron <jic23@jic23.retrosnub.co.uk>
To: "Zbyněk Kocur" <zbynek.kocur@fel.cvut.cz>
Cc: linux-iio@vger.kernel.org, Andreas Klinger <ak@it-klinger.de>
Subject: Re: SRF04.c - wrong range for filter (line 145)
Date: Sat, 22 Jun 2019 11:52:05 +0100 [thread overview]
Message-ID: <20190622115205.767777c2@archlinux> (raw)
In-Reply-To: <B08A7378-8CBD-4B77-B18D-B0C157FAEC07@fel.cvut.cz>
+CC Andreas.
On Mon, 17 Jun 2019 21:21:37 +0200
Zbyněk Kocur <zbynek.kocur@fel.cvut.cz> wrote:
> Hello,
>
> I try to use linux kernel module for proximity sensor SRF04 and i was not able to measure distance longer than 1.5 m. The problem is on implementation maximum range filter in function srf04_read, line 145. The reasoning assumes that the distance to 3 meters is limited, but the direction back and forth is neglected. Therefore, the resulting limit is a maximum of 1.5 meres and not a required 3 meters. The solution is to come out of the formula:
>
> * distance 2 * 3 m
> * time = ---------- = --------- = 18808777 ns
> * speed 319 m/s
> *
>
>
> Best Regards,
> Zbyněk Kocur
> ---
> email: zbynek.kocur@fel.cvut.cz
> phone: +420 224 354 054
> web: http://www.fel.cvut.cz
> Department of Telecommunications Engineering
> Faculty of Electrical Engineering
>
prev parent reply other threads:[~2019-06-22 10:52 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-17 19:21 SRF04.c - wrong range for filter (line 145) Zbyněk Kocur
2019-06-22 10:52 ` Jonathan Cameron [this message]
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