Hootoo + OpenWrt + Velleman K8055N

One of the things that I had kicking around at home was a Velleman K8055N (actually mine was the pre-made version, the the VM110N) - but I think they are essentialy the same thing. I decided that it would be really cool to try it out on OpenWrt ... so that eventually I could try interfacing a tiny embedded Linux machine with the outside world.

Some quick googling led me to this driver which I tried on a Debian Virtual Machine first, and then decided to run it on my Hootoo HT-TM02. I used a docker container to build the kernel module according to the instructions, and then copied it over onto the device for installation.

The first attempt at installing the module gave the following error:

Collected errors:
 * satisfy_dependencies_for: Cannot satisfy the following dependencies for
 kmod-k8055d:
 * 	kernel (= 3.18.23-1-e2416fa0abee73ea34d947db4520f4e9) *

Which I assumed was just OpenWrt being a bit over cautious, because I was actually running kernel v3.18.23. So I took the risk and overrode the error, with this command:

opkg install /tmp/kmod-k8055d_0.2.1_3.18.23-ramips-1_ramips_24kec.ipk --nodeps

Perfect, it worked! So the K8055N is now accessible in the file system under /proc. To celebrate, I hooked up the digital-to-analoge converter to an old voltmeter, so I could watch the needle bounce around in response to what I'm typing on the command line:

I think that's pretty awesome, although I don't know what I'll use it for. Perhaps I'll build some kind of Web API and allow inputs and outputs to be controlled from a browser. Or ... come to think of it, I could build a really cool CPU meter with the output showing via the needle of the voltmeter.