Date: Fri, 29 Aug 2014 21:51:21 -0300 From: Evandro Nunes <evandronunes12@gmail.com> To: Luiz Otavio O Souza <lists.br@gmail.com> Cc: "freebsd-arm@freebsd.org" <freebsd-arm@freebsd.org>, Rui Paulo <rpaulo@felyko.com> Subject: Re: HC-SR04 and FreeBSD Message-ID: <CAG4HiT7mKZOTKMzw=oic2iGNVNnoV2zcSQo=en4OJZJuc-pzjA@mail.gmail.com> In-Reply-To: <CAB=2f8w8vYr_zrN21nBhyR=Q4yUUw1Pa=_7zOZ3khS_NU9CEVQ@mail.gmail.com> References: <CAG4HiT6wwbmSA_KWsgHOqdeZVOCUsdhRxDhMubvkG1tEwVH5Sw@mail.gmail.com> <5D802942-2D0F-4324-8212-C2871EEB6327@FreeBSD.org> <CAG4HiT6fiqVXMoqcJra1Yh8aFVbOcezP8rRqst6WC8aHuaF_rA@mail.gmail.com> <01562FB1-32C6-45AF-AB77-5BB80526E18C@FreeBSD.org> <CAG4HiT4kKz18iauXfuF0Dpv-USghunssUvwkTF7bDx_gE_VS2w@mail.gmail.com> <CCD5AEE5-798D-4EAC-BAE7-A086DE55B5D2@FreeBSD.org> <CAG4HiT6YUBCxXrK_KyRW6zTthPa-wDe=A9=CmMHQf-Gh54s7QA@mail.gmail.com> <EA5A973C-960A-4B0F-A690-8AA9BF66244A@felyko.com> <CAG4HiT4EbX=Lar_o8YZc5B51Yao1-B=Ebck0vQajyzoZwesWwQ@mail.gmail.com> <CAB=2f8zBDTVkQd15C_icZpOMC14XxFycW_ZR2Sa--updv=dX2w@mail.gmail.com> <53F8FED8.6030409@freebsdbrasil.com.br> <CAG4HiT4RXsUyGfjDDTTJPoeB8bqpY39z6C-_f0S3Zmka0C8gNQ@mail.gmail.com> <3949AF9C-B5BD-44E8-A049-21F26B8B6B9A@freebsdbrasil.com.br> <CAB=2f8xyu1EwL3zft8E%2BSXRL66vdYSjgcSuhF7Kva9zDatGtXA@mail.gmail.com> <411C643B-BC46-494E-919B-39098FB87EEA@freebsdbrasil.com.br> <CAB=2f8w8vYr_zrN21nBhyR=Q4yUUw1Pa=_7zOZ3khS_NU9CEVQ@mail.gmail.com>
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hello luiz, it looks promissing! i will try it by the weekend thank you very much it seems like a begining for a libary, or at least an examples collection, a sonar sensor utility, a relay which you helped me before, the temperature sensor patrick mentioned and you seem to have it working... I guess they are the basic and popular stuff On Fri, Aug 29, 2014 at 3:07 PM, Luiz Otavio O Souza <lists.br@gmail.com> wrote: > Okay, so i got my hands on one HC-SR04 and got it working quite > easily. Two consecutive GPIO readings takes from 15 to 30 usec which > gives a good precision for this case (readings above 116 usec). > > I written a simple C program to program the GPIO pins, trigger the > sensor and read back the duration of echo pulse, it give me good > readings using the datasheet formula, so i'm happy with it. Build it > with: cc -o hc-sr04 hc-sr04.c > > I'm using the wiring suggested at (voltage divisor on echo pin): > > https://www.modmypi.com/blog/hc-sr04-ultrasonic-range-sensor-on-the-raspberry-pi > > The trigger and echo pin is connected to pins 2 and 3 respectively. > The module is powered from DGND and VDD_5V. > > This maybe a good candidate to be on Wiki. > > Luiz >
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