I2C not working right

Hello everyone,

I have a problem with my bbb, somehow all i2c channels are not working properly. Only a fraction of all available addresses are scanned.

This is the output:

debian@BeagleBone:~$ ls -la /dev/i2c-*
crw-rw---- 1 root gpio 89, 0 Apr 17 15:09 /dev/i2c-0
crw-rw---- 1 root gpio 89, 1 Apr 17 15:09 /dev/i2c-1
crw-rw---- 1 root gpio 89, 2 Apr 17 15:09 /dev/i2c-2
debian@BeagleBone:~$ i2cdetect -y 0
Warning: Can't use SMBus Quick Write command, will skip some addresses
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                                                 
10:                                                 
20:                                                 
30: -- -- -- -- 34 -- -- --                         
40:                                                 
50: UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60:                                                 
70:                                                 
debian@BeagleBone:~$ i2cdetect -y 1
Warning: Can't use SMBus Quick Write command, will skip some addresses
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                                                 
10:                                                 
20:                                                 
30: -- -- -- -- -- -- -- --                         
40:                                                 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60:                                                 
70:                                                 
debian@BeagleBone:~$ i2cdetect -y 2
Warning: Can't use SMBus Quick Write command, will skip some addresses
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                                                 
10:                                                 
20:                                                 
30: -- -- -- -- -- -- -- --                         
40:                                                 
50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60:                                                 
70: 

I use this image AM335x 11.7 2023-09-02 4GB microSD IoT. All packages are up to date and i2c-2 is enabled with ‘uboot_overlay_addr0=/lib/firmware/BB-I2C2-FAST-00A0.dtbo’

Do any of you have any ideas? Did I forget to set something?

Thank you very much for your help.

1 Like

pass the -r option:

debian@21-am335x-bbb:~$ sudo i2cdetect -y 0
Warning: Can't use SMBus Quick Write command, will skip some addresses
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                                                 
10:                                                 
20:                                                 
30: -- -- -- -- 34 -- -- --                         
40:                                                 
50: UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60:                                                 
70:  
debian@21-am335x-bbb:~$ sudo i2cdetect -y -r 0
     0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
00:                         -- -- -- -- -- -- -- -- 
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
20: -- -- -- -- UU -- -- -- -- -- -- -- -- -- -- -- 
30: -- -- -- -- 34 -- -- -- -- -- -- -- -- -- -- -- 
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
50: UU -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 
70: UU -- -- -- -- -- -- -- 

Regards,

Thanks, this was the problem.