On Mon, Dec 7, 2015 at 7:36 AM, Ken Pettit <[email protected]> wrote:
> The implementation in the picture is a daughter card for the Raspberry Pi 2 > B (a "Pi Hat"). It connects with the Model T parallel port for primary > communication of video data, but also has an RS-232 port (and a BCR port). > It also has a "pass-through" LPT connector where your old LPT printer can be > connected. Making TDock a Pi Hat was the simplest and cheapest approach, > though it is not very portable and has the requirement of booting / shutting > down Linux. > With a juice pack or other gadget the Pi can be portable. We're going to be testing one of these boards where I work very soon: http://www.modmypi.com/raspberry-pi/breakout-boards/pi-modules/ups-pico This gives the Pi the chance to power down gracefully if power is cut. Also it has a hookup for adding an external battery so you can power the pi for hours if you like. We're going to be testing it because of stability issues due to hard power cycles. This is important because at least with the default images floating around for the Pi, the boot image corrupts easily. In our case, we need portions of the SD card filesystem to be read/write. I've also done various things to lock down the file system making specific portions read-only, set noatime, log to ramdisk instead of SD card, etc but I don't know how much if at all these changes will help until we really start rolling it out in larger numbers. -- John.
