Thursday, September 26, 2013

Ralink RF3070 USB wireless support finally added to Linux

For a long time, these cheap Chinese USB wifi adapters didn't work in Linux. Believe it or not, I wiped my old laptop's Linux partition and tried FreeBSD and OpenBSD just to see if they supported it - but they didn't either.
So I reinstalled Linux and eventually produced a patch back in June to add support for the device, but for whatever reason it was ignored.

Now, though, one of the maintainers has implemented a proper patch and it looks like the RF3070 will soon work out-of-box in Linux.

Yay!

Monday, May 13, 2013

OpenCV build: "Could NOT find JNI" (Ubuntu)

While trying to build OpenCV so I could use the new Java bindings, I kept getting this somewhat confusing message:
Could NOT find JNI (missing: JAVA_AWT_LIBRARY JAVA_JVM_LIBRARY)

What does it mean - did I need to set environment variables for the AWT and JVM libraries? Surely they're both already installed. What does it even mean to say "Could NOT find JNI", since JNI is a part of Java which is installed?

Turns out I needed to manually set the JAVA_HOME environment variable:
export JAVA_HOME=/usr/lib/jvm/java-1.7.0-openjdk-amd64
Why Ubuntu doesn't automatically set this when you install the openjdk7 package, I have no idea.

Sunday, February 24, 2013

Eye queue

This comment by "Cabochon1360" on one of David Mitchell's Youtube videos struck me today (far more than the video), and sums up my own feelings better than I could have.
In my teens, I was proud of my allegedly high IQ. But decades of failures and other humbling experiences have shown me it's just one personal characteristic, and not the most important one.
Another thing to bear in mind is that telling your kids they did well on a test because they're smart hinders their future performance. Perhaps counter-intuitive but it's been demonstrated in a number of studies (even when performed on adults, AFAIK).