Unable to get i2c connection to work on Orange Pi Zero 2

[njx]

I have been trying to get DS3231 to work with the OrangePi Zero 2 via the i2c bus.

I have tried setting the following settings in /boot/armbianEnv.txt

overlay_prefix=sun8i-h6
overlay=i2c0 i2c1 i2c2

However, I am not able to use i2c tools to read the DS3231.

Any suggestions are welcomed. Thank you in advance!

[serg_stetsuk]

Hi. It's probably a bit late. On OrangePi Zero2 thereis i2c3 interface. Thus you must create your own DT overlay for i2c3 interface. See https://github.com/armbian/sunxi-DT-overlays/blob/master/sun50i-h6/sun50i-h6-i2c2.dts as an example. Let's say you create file sun50i-h6-i2c3.dts:

/dts-v1/;
/plugin/;

/ {
	compatible = "allwinner,sun50i-h6";

	fragment@0 {
		target-path = "/aliases";
		__overlay__ {
			i2c3 = "/soc/i2c@5002c00";
		};
	};

	fragment@1 {
		target = <&i2c3>;
		__overlay__ {
			pinctrl-names = "default";
			pinctrl-0 = <&i2c3_ph_pins>;
			status = "okay";
		};
	};
};

 

Compile this file into a binary device-tree overlay blob:

dtc -I dts -O dtb -o sun50i-h6-i2c3.dtbo sun50i-h6-i2c3.dts

 

Set permmissions and copy compiled file into /boot/dtb/allwinner/overlay:

chmod +x ./sun50i-h6-i2c3.dtbo
sudo cp ./sun50i-h6-i2c3.dtbo /boot/dtb/allwinner/overlay

Then use the following in your armbianEnv.txt:

overlay_prefix=sun50i-h6
overlay=i2c3

 

Edited January 7 by serg_stetsuk
improved answer