Am Sun, 16 Apr 2023 10:01:08 +0200 schrieb Diederik de Haas <didi.deb...@cknow.org>:
> On Sunday, 16 April 2023 04:47:37 CEST Rick Thomas wrote: > > I've got a Raspberry Pi 4B (4GB) with a DS3231 RTC module. I can > > make the combo work with Ubuntu and RaspberryPI-OS. I'd like to > > try it with the plain-vanilla Debian from > > <https://raspi.debian.net/tested-images/> but I can't find > > instructions for activating the I2C and RTC hardware in that OS. > > Documentation/devicetree/bindings/rtc/rtc-ds1307.yaml in the kernel > source describes how one could use it ('compatible = "maxim,ds3231"' > for DS3231). I think you should make a DeviceTree Overlay, but I > don't know how to do that. I got this working with that systemd unit on a Rpi3 but should also work on a RPi4. Maybe you need to adjust the modprobe sequence. I guess the 2708 is 2835 on the Pi4. cat /etc/systemd/system/hwclock-pi.service [Unit] Description=HWClock at the I2C Bus of the Raspberry pi Before=basic.target Conflicts=shutdown.target DefaultDependencies=no [Service] Type=oneshot ExecStart=/bin/sh -c "modprobe i2c_bcm2835 && modprobe i2c_bcm2708 && modprobe rtc_ds1307 && sleep 1 && echo ds1307 0x68 > /sys/class/i2c-adapter/i2c-1/new_device && /sbin/hwclock -s" ExecStop=/sbin/hwclock -w RemainAfterExit=yes [Install] WantedBy=basic.target
