Sunday, July 21, 2013

BeagleBone Black - First Impressions and Astronomical CCD's

Bought a BeagleBone Black from element14 last week, cost was S$ 66.70.  Since then element14 has lowered the price to S$ 56.95.  The BBB is an Arduino-sized Linux machine with a 1GHz Texas Instruments Sitara SoC, 512MB of RAM, 2GB of onboard eMMC NAND flash with the Angstrom Linux distribution, a micro-SD card slot, 10/100 Ethernet, a regular-sized USB host port, a mini-USB slave port, and a micro-HDMI port for video output.

So far I haven't used it with the micro-HDMI port for lack of the proper adapters, I've wired it up to my access point (which has a bunch of Ethernet ports) and powered it off an iPad charger with a USB cable.  I have tried both the latest version of Angstrom Linux, and Ubuntu 12.04 LTS for the BB.   Angstrom is a fairly strange distribution, as it's based on some OpenWRT tools. Ubuntu is much more predictable to a desktop Linux user; however it is missing Chromium and the OpenCV libraries, which are both bundled with Angstrom.

I got a 16GB Transcend micro-SD card (about S$ 17). The onboard eMMC is too small to install a full OS. Currently there is a bug or feature limitation on the BBB where, if you boot off the eMMC, the micro-SD card is not visible; so the only way to use the micro-SD is to put both the OS and the separate file system on it. To get a full OS (e.g. I installed KStars on Ubuntu) you really need a micro-SD card.  16GB seems to be the sweet spot in terms of price/storage.

I've had some ambitions of using the BBB as a stand-alone astronomical imaging controller, e.g. when connected to a telescope and two cameras, it would perform telescope control, auto-guiding, and image capture.  I have a Meade DSI lying around, and with some Makefile kung fu I managed to get the Meade Deep Sky Imager code for Linux to compile on Angstrom.  I need to get my hands on the Meade DSI firmware, and see if I can get things working.

Supporting my QHY8 astronomical camera would be easier on Ubuntu (because the CCD software requires a Qt development environment) but I'll get to that later; I'm not even sure if my QHY8 is supported, since the CCD software specifies the QHY8L.  Tried changing the VID's in CCD but the QHY8 doesn't work.