This year at Sabotencon marked chibi-neko’s third convention with our raspberry pi based digital signage. We added a couple of new features, and come up with a list of to-do’s.

A little background info is in order first. Since these conventions charge an arm and a leg for power (something like $100/day plus setup fees last time I checked) we had to come up with something that was portable, fairly low power, and not take up too much room. I had a raspberry pi sitting around and had been wanting to find a project for it, so there you go.

Space was at a premium we settled on an old 17" Dell monitor that was on a base that could be adjusted for height and let us rotate the monitor into a portrait position, since most of her art was oriented that way. On the first day of the first show I thought we could power the monitor with a large computer UPS system, but that only lasted for about an hour. The next day we picked up a 35ah AGM battery from (Batteris-Plus-Bulbs)[http://www.batteriesplus.com], connected the 12v->120v inverter that I had in our RV, and that combination lasted all day.

After getting Raspian which is a pi version of the Debian linux distribution, I was able to get X configured to auto-login at boot and execute a script that just fired off the feh image viewer which was pointed at a directory with images of her photos and signs to be displayed.

This year she wanted to also have it play her (speed-draw video)[https://youtu.be/oHIm7YmzKBg] of her drawing one of her Persona 5 fan art characters. It took some trial and error to come up with the right combination, but in the end I wound up using a shell script with an endless loop that plays one iteration of the existing slides via feh, and then plays the mp4 video using (omxplayer)[https://www.raspberrypi.org/documentation/raspbian/applications/omxplayer.md] which is a pi specific video player that uses hardware accelleration. There were a couple of glitches in using that player, but adding the –no-keys and –no-osd seemed to clearn things up. I’ll have to do an software update on the pi after the show to see if that helps also.

Next up we are planning to add more screens and move to have everything displayed using the info-beamer software which will add much better scripting capabilities along with coordinating multiple screens. I’m also looking to see if we can re-power the entire setup with mikata power tool battery packs and buck converters, which should be more efficient than the 120v inverter.