Fun with the Raspberry Pi

A raspberry pi. I still can’t get the HDMI output working, which makes it a bit anticlimactic. Need to pick up a component video cable….

One of the many projects we’re planning to run involves getting some Raspberry Pi computers into rural libraries and/or community centers and giving youths a chance to learn programming.  We’re particularly looking at bringing on just-graduated students, who typically hav about eight months of dead time between the end of secondary school and the start of university.

So I’ve gotten my hands on a couple RP’s; the last few days I’ve really started hacking around with one in particular.  My short-term goal is to get a working Sage binary together, built for the Pi.  (Admittedly, I haven’t tried the ARM binary at sagemath.org, but it claims to not be built for the particular processor in the Pi.) It will generally be a good public service to get a Pi-ready build of Sage out there in the world.  One will probably need an 8gb sd card to run it properly, though, as the binary will probably weigh in at a bit over 2gb.

As mentioned in the caption, I still haven’t managed to get the video working.  HDMI devices are hard to come by in Kenya.  So I picked up a HDMA-VGA converter, but it hasn’t been working.  Presumably, I should just pick up a cheap TV somewhere and plug into the component jack on the RP, and that’s certainly what we’ll do when we deploy the devices.  But in the meantime I’ve been running headless, ie, without a monitor or keyboard.

It was a bit complicated to get set up in the first place, but now that all is together it’s no problem.  The RP comes with sshd pre-enabled, making it very easy to log in ‘remotely’ from accross the room and run all the processes one desires.  The main trick was getting the RP onto the local network set up by my android cell phone and figuring out which IP address it had ended up with.  I did this by writing a cron job to dump the ifconfig info into a text file from time to time, then reading off the IP address from that.  Luckily, the phone is pretty nice about giving out the same address on either side of a reboot.

But for now, all there is to do is wait…  The Sage build takes a while on the Pi, it seems.  The record for the longest Sage build was 14 days, on a Samsung phone.  I’m confident it should be faster than that, but I’m not sure how much faster….