Which Khadas SBC do you use?
VIM3
Which system do you use? Android, Ubuntu, OOWOW or others?
Ubuntu 20.04 kernel 4.9
Which version of system do you use? Khadas official images, self built images, or others?
khadas official
Please describe your issue below:
I need to understand about i2c-3 working on VIM3 .
It doesnt matter if I enable or diable i2c-3 in /boot/env.txt using the overlays= line I observe the following
-
there always two entries in /dev namely
i2c-3
i2c-4 -
The dmesg log always contains references to i2c-4 and not i2c-3 like below
root@Khadas:~# dmesg | grep i2c
[ 0.998816] i2c /dev entries driver
[ 7.358582] i2c i2c-4: sensor_probe: kxtj3,ffffffc046d52000
[ 7.359355] input: gsensor as /devices/platform/soc/ff800000.aobus/ff805000.i2c/i2c-4/4-000e/input/input4
root@Khadas:~#
I havent connected the board to anything and when i scan i2c-3 like
i2cdetect -y 3 I get
root@Khadas:~# 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: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
root@Khadas:~#
and i2cdetect -y 4 gives this
root@Khadas:~# i2cdetect -y 4
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- UU --
10: -- -- -- -- -- -- -- -- UU -- -- -- -- -- -- --
20: UU -- 22 -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: -- UU -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- --
root@Khadas:~#
My question is how do we use i2c-3 and what is i2c-4?
what is there at address 0x22 on i2c-4 bus ? I havent attached the board to any other chip.
which pins I should use for i2c are these 22 and 23 ? these are for i2c-3 and not for i2c-4 ?
Please advise as I need to configure and use i2c bus on VIM3
Thanks
Nabeel