I got the steering wheel buttons to work with the Avin Android head unit. I got a cable harness for head units with Omega connections. Then I got the wires that are coming from the steering wheel. In this case it is just one connection from the car that connects to one of the Key-connections on the Avin unit.
On this connector it is the white cable that has the steering wheel button signal. I will fit a frame around the unit, it needs some trimming to fit, haven't done that yet.
Here is how the unit looks and as you see I'm adjusting the volume from the steering wheel.
This unit is in fact an Android tablet fit for use in cars, it has a couple of special apps for auto use, like a radio app that uses your cars antenna and speakers. But you can download music to the unit and store in its memory or on memory-cards. It has Wi-Fi so you can download apps from your homes network. I have a navigation app that stores the maps locally in the unit and it is a lot of data to download.
You can connect a USB Modem stick to it to get internet access when you drive or you can share your phones internet connection over the Wi-Fi.
This kind of unit will give us modern technology to our cars comparable to Apples CarPlay or Android Auto but better since you can use any kind of Android App, not just the ones compatible with Android Auto. And for me living in Sweden we haven't yet got Android Auto.