Need help with Interface an I2C LCD on rock5b

[natedog]

I have an LCD like this:

In-Depth: Interfacing an I2C LCD with Arduino

I pinned #4 power, #6 Ground, *#8 SCL, #10 SDA
(https://wiki.radxa.com/Rock5/hardware/5b/gpio )

ls /dev/i2c*
/dev/i2c-0 /dev/i2c-1 /dev/i2c-10 /dev/i2c-11 /dev/i2c-4 /dev/i2c-6 /dev/i2c-7 /dev/i2c-9

i2cdetect -y 1
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – – – – – – – –
10: – – – – – – – – – – – – – – – –
20: – – – – – – – – – – – – – – – –
30: – – – – – – – – – – – – – – – –
40: – – UU – – – – – – – – – – – – –
50: – – – – – – – – – – – – – – – –
60: – – – – – – – – – – – – – – – –
70: – – – – – – – –

I would expect it to show at 0x27

What am I doing incorrect? Please help.

Thanks,

[Jodels2002]

Hi,

#9 SDA -> should be 10? ( 9 is GRD)

10 GPIO0_B6 UART2_RX_M0 I2C1_SDA_M0

[natedog]

My mistake it was #10. Here is a pic of the setup.

[dominik]

As far as I remember UU on i2c means that there is no driver or kernel module for particular device. Is it disappearing when disconnected?

BTW: You should also use cables with their color codes, gnd is black and vcc should be red, as in attached picture and gpio, this makes life bit easier to not swap anything and burn it. Those two are most important.

[natedog]

I hear ya on the color cables, just working with what I have at the moment.

It should look something like this. Normally “27” represents the lcd. It looks like this on a pi and other boards like an odroidM1.

Its missing when I i2cDetect on all available interfaces. i.e.:
ls -l /dev/i2c*
crw-rw---- 1 root i2c 89, 0 Mar 7 15:44 /dev/i2c-0
crw-rw---- 1 root i2c 89, 1 Mar 7 15:44 /dev/i2c-1
crw-rw---- 1 root i2c 89, 10 Mar 7 15:44 /dev/i2c-10
crw-rw---- 1 root i2c 89, 11 Mar 7 15:44 /dev/i2c-11
crw-rw---- 1 root i2c 89, 4 Mar 7 15:44 /dev/i2c-4
crw-rw---- 1 root i2c 89, 6 Mar 7 15:44 /dev/i2c-6
crw-rw---- 1 root i2c 89, 7 Mar 7 15:44 /dev/i2c-7
crw-rw---- 1 root i2c 89, 9 Mar 7 15:44 /dev/i2c-9

I am thinking the driver is not loaded, or there is some configuration required on the Rock5B, but I don’t see any documentation on how to enable i2C. What do you think, any ideas?

[natedog]

Found the config. It would not work on I2C1_SCL_M0 and I2C1_SDA_M0, which was my preference but got it to work on I2C7_SDA_M3, I2C7_SCL_M3