JCrete2013:Lightning Talks

From WikiEducator
Jump to: navigation, search
Lightning Talk - Java on the Raspberry Pi
Convenor: Chris Newland

No participants listed.


More of an ad-hoc demo with whoever was around in the hotel lobby.
Chris presented a demo of wearable JavaFX computing using a Raspberry Pi running JDK8 ARM preview.
The Pi has 256MB RAM (512MB versions are now available), a 700MHz ARM6 CPU (said to be equivalent to a Pentium II 300MHz), 2 USB ports, HDMI, composite video out, analogue audio out, 100MB Ethernet, GPIO. It is powered by 5V micro USB connector and requires a power supply capable of 1.2A if both USB ports are in use.
Its small size makes it an interesting base for a wearable computer project. It can run a full Java 8 JRE and JavaFX performs acceptably on its VideoCore GPU.
I have built a wearable software suite driven by 4 inputs (UP, DOWN, SELECT, BACK). Input is via a USB mouse worn on the index finger and UP/DOWN are mapped to the mouse wheel and SELECT/BACK to the 2 mouse buttons. Output is to a 3.5 inch TFT display or to a monocular video display mounted on a pair of glasses frames. Power is by a 12000mAH recharging pack which powers the wearable system for around 10 hours including WiFi usage.
The software is a tree of application "nodes" and includes a clock, memory usage viewer, photo viewer, animation test, read-only Twitter client, read-only POP3 client, and Google Maps client.
At present JavaFX requires the GPU to be allocated a large fraction of the RAM (I use 128MB) which leaves just 128MB for the rest of the JVM and the OS. My application uses a heap of under 20MB and is not aggressively optimised.
To be continued.


Add screenshots.
Upload code to Menew on GitHub