Raspberry Pi, servo motor, gpio, i2c and soldering weekend

This weekend I decided to work on my soldering skills and finally assemble the PWM driver PCA9685 I bought from Adafruit couple weeks back. Not all solder points looks perfect, but I’ve manage not to burn the PCB which I consider a major success. I thank all the
guys how put soldering tutorials on the youtube!


Then I played with software.
* I2C: I used python to steer servo controller via I2C interface. For some reason the Raspbian image has I2C kernel module disabled, so I had to comment blacklist i2c-bcm2708 in /etc/modprobe.d/raspi-blacklist.conf and the add i2c-dev and i2c-bcm2708 to /etc/modprobe to enable them to start.
* GPIO: Raspbian has all libraries loaded by default for GPIO development in python. I had encountered hardware problem instead – there’re many sources on the web describing pin layout of GPIO port, but non of them says which pin is the physical pin 1! I have some gaps in basic knowledge, so I have missed a small rectangle marking P1 – it’s the one nearest to the side of the board in bottom row. See a picture with pins P3, P5, P9, P10 and P11 connected:

And here it is – Raspberry Pi waving The Flag of the United States of America


MGPlayer on Raspberry PI (javafx!)

I’ve just “successfully” run my MG Podcast Player on Raspberry Pi using just released JDK8 for ARM Preview.

Performance isn’t great compared to desktop system and it doesn’t actually play mp3 files (Media are not supported yet), but having ability to run a java 8 application on $35 is amazing by itself!

If you want to try follow the steps on oracle site to install the image and then run:
$ /opt/jdk1.8.0/bin/java -Djavafx.platform=eglfb -jar MGPlayer.jar

* -Djavafx.platform is crucial as it let javafx work on OpenGL ES 2.0 embedded device
* I’ve installed java on my raspbmc image