Re: DS1307 on rpi4B
Daniel O'Connor <[email protected]>
| Newsgroups | gmane.os.freebsd.devel.arm |
|---|---|
| Message-ID | <[email protected]> |
Hi, > On 8 Dec 2024, at 12:35, 風來散人 <[email protected]> wrote: > I modified config.txt to load this dtbo and add one more line to set GPIO pins in [pi4] > > gpio=12,13=a5,pu > > 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. > > 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