Re: Activate a Real Time Clock chip on I2C in Raspberry Pi 4B with Debian (not Raspbian)
That helps some...
root@pi:~# i2cdetect -l
i2c-3 i2c bcm2835 (i2c@7e804000) I2C adapter
i2c-1 i2c Broadcom STB : I2C adapter
i2c-2 i2c bcm2835 (i2c@7e205000) I2C adapter
i2c-0 i2c Broadcom STB : I2C adapter
and:
root@pi:~# i2cdetect -y 3
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- 68 -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
All other busses (0 1 and 2 as arguments to i2cdetect give no devices)
So, if I change "i2c-1" to "i2c-3" in the "echo > /sys/class ..." I find that the hwclock command now works!
Now all I have to do is get all that into a systemd service file so it is done at boot time.
It's late now. I'll try that tomorrow!
Thanks very much to all who contributed!
Rick
PS: Anybody who can explain why it has to be bus 3 -- and how I could have predicted that -- will get a hundred Internet guru-points!
On Mon, Apr 17, 2023, at 3:39 AM, Reco wrote:
> Hi.
>
> On Mon, Apr 17, 2023 at 02:48:44AM -0700, Rick Thomas wrote:
>> Sadly, when I do:
>> i2cdetect -l
>> I get nothing back. Leading me to conclude that there are no busses available.
>
> "modprobe i2c-dev" should fix that.
>
> Reco
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