Date: Sun, 8 Dec 2024 14:10:54 +1030 From: Daniel O'Connor <darius@dons.net.au> To: =?utf-8?B?6aKo5L6G5pWj5Lq6?= <furaisanjin@gmail.com> Cc: FreeBSD ARM List <freebsd-arm@freebsd.org> Subject: Re: DS1307 on rpi4B Message-ID: <BCFF0CD3-574A-4472-B8BB-7EECFCFFE22A@dons.net.au> In-Reply-To: <CAJzLSnw5uuVhc9=HC5sCRv0nBzPXfbq_WVfYrmMg-h99hyRO-A@mail.gmail.com> References: <CAJzLSnxOALkCztZUa-zpUH30g1O0nUfQb4X2=4o_VDv3WTEdaQ@mail.gmail.com> <431FB386-F515-4D77-A855-18055A48E432@dons.net.au> <CAJzLSnw5uuVhc9=HC5sCRv0nBzPXfbq_WVfYrmMg-h99hyRO-A@mail.gmail.com>
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Hi, > On 8 Dec 2024, at 12:35, =E9=A2=A8=E4=BE=86=E6=95=A3=E4=BA=BA = <furaisanjin@gmail.com> wrote: > I modified config.txt to load this dtbo and add one more line to set = GPIO pins in [pi4] >=20 > gpio=3D12,13=3Da5,pu >=20 > This works fine and RTC starts working. One strange thing is that = "gpioctl -l -v" doesn't show correct pin setting somehow. I assumed = there should be PU on pin 12 and 13. >=20 > pin 12: 1 pin 12<>, = caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB> > pin 13: 1 pin 13<>, = caps:<IN,OUT,PU,PD,INTRLL,INTRLH,INTRER,INTREF,INTREB> Strange - I don't know if the pull ups on the SoC are suitable for I2C. = The modules I have used have pull ups as real resistors - in internal = pull-ups on SoCs tend to have a pretty broad range due to the way they = are fabricated. -- Daniel O'Connor "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum
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