Adventures with a Raspberry Pi

Having received TWO Raspberry Pi’s for Christmas I decided to explore some of the simpler possibilities of this little machine. This post describes what I managed to achieve during the Christmas break. There isn’t anything very original here, all the steps are basically things cobbled from other sources, but hopefully it will give the reader an idea of the things that can be done. it is worth pointing out that I am very much a Linux novice so if I can do these steps then any technically savvy person can.

Basic setup plus Node.js and Ewd.js

I wasn’t expecting to find too much ‘out of the box’ but I was still surprised to find nothing at all. Even though one of the Pi’s came with a starter kit. You literally get just the board without even a flyer saying look here for instructions. This could be very daunting for a lot of people. Fortunately I had Rob Tweed’s excellent set up instructions in appendix 4 of his   Ewd.js manual. This not only describes how to get the Pi up and running but also how to install Node.js and ewd.js on it and get the ewd monitor application up and running. There are also additional instruction on how to install Mongodb.

There are some important things to note if you are going to follow these steps.

First of all ensure that when you first install Raspian from the SD card enable SSH. This allows you to then basically disconnect the keyboard and screen and do everything from tools like WinSCP and Putty on another computer.

Secondly, and this one caught me out with some of the installs, check that the Pi is managing the date and time correctly. I have a hardware firewall that was blocking NTP which meant that the Pi could not establish the current date and time. The Pi does not have a system clock so it was always booting as some date in June 2013. This really messed up some of the install procedures wasting a lot of time.

Install Java and Run a Minecraft Server

My kids play minecraft all the time so I thought it would be cool if I could get a local minecraft server up and running on a Pi. I found the instructions for this here . I skipped most of the first part as I wasn’t quite ready to overclock my Pi just yet. It also took me a bit of playing around to get the syntax right to download the latest and greatest java version but other than that the instructions were very clear and easy to follow. It took a fair while for things to process for the initial setup but had my kids up and running minecraft on their laptops to my little pi server on my local wireless (once I had punched a hole for the Pi from my local to my wireless network on the firewall). Dad was cool again!!

Move the OS from the SD card to a MicroUSB stick

I had bad memories about the longevity of SD cards and also didn’t like having mine sticking out from the side of the Pi box. I also had already had to manually power-cycle the Pi a few times and crossed my fingers each time that the SD card hadn’t been corrupted. This didn’t strike me as a great way to run things so I did a bit of digging around to see if I could boot the Pi off a MicroUSB stick that was somewhat more robust. As it turned out you can’t totally replace the SD card but you can reduce its use to a single file read on boot only. This enables you to pull the card out once it has booted so there is much less chance of it being corrupted at some stage. This took quite a lot longer to do but if you CAREFULLY follow the instructions here it is worth it. I now have 32gb file space to play with and a lot less worries. I would recommend following the ‘Extended Instructions’ as this enables the USB stick to be moved around (I currently have mine on a usb hub) further reducing the bits that need to be sticking out of the Pi

Do a bit of mining

One of the other things I have been investigating and playing around with over the Christmas period is Cryptocurrencies. Unfortunately I missed the boat ( as usual) so not going to make any money but it has been a useful learning experience and I am now the proud owner of 0.000696 Bitcoins, 233.09152 QuarkCoins and 0.2 LiteCoins (contributions gratefully received at 1KVd1K4hRVFuEQori8Sn43ExbRt2QBHchd,  QR9Xhcg3GZtErvHJ3ozKuGMXpQWoWq8waK, or bb586d3b72f3f1d2c5058301b481074c respectively). Much of this thanks to the generosity of Microsoft Azure but that’s another post.

I knew it was probably past the capabilities of my little Pi but I thought I would have a go doing a bit of coin mining with it.

I found some basic instructions for installing LiteCoin mining on a Pi  here (I did find that I had to replace git:// with https:// in order to do the clone command.) and soon had my Pi chugging away achieving very little (again, I decided not to overclock).  I let it run for a day without success before deciding to try for a lesser coin (The quark). I basically had to repeat the same instructions but with a couple of quirks. Replace the git clone command with this repository https://github.com/Neisklar/quarkcoin-cpuminer and ensure that you override the target directory to clone into. Other than that, and remembering to use the new directory name, the instructions work.

Unfortunately even at this low level my Pi was unable to find a single coin block in 24 hours!.

MUMPS on a Pi

Well it just had to be done. Unfortunately neither of the two major implementations will run on a Pi but I did find MUMPS V1 that would install and run. The instructions were pretty straight forward for the basic empty mumps database though I did struggle a bit when trying to install the VistA fileman database. One thing I did find (and haven’t yet solved) is that when you come out of the mumps shell the putty window is messed up and I have to logout and go back into a new one to correct it. I have seen this behavior before but can’t remember the solution, perhaps someone could add a comment to remind me.

Conclusion and some last tips

Well that concludes me Christmas adventures with my Pi. Hopefully it will give some people some ideas of things that can be done with the wonderful little machine. I have not, as yet, investigated any of the more electrical possibilities which make this machine come into its own.

One invaluable tip, on the initial boot screen of the Pi there is a recovery option which allows you to edit some of the boot files in situ. Wish I had discovered this before taking the SD card back to the PC and recopying it after I messed up one time.

I may add further bits to this as I remember other things I have missed (it was Christmas after all). Please feel free to comment with other suggestions and ideas for this machine.

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2 comments

  1. Mike Clayton · · Reply

    Hi Chris, have you tried typing ‘reset’ at the prompt after coming out of the MUMPS V1 shell? I haven’t tried this with PuTTY yet, but it fixed the display issues for me when connecting to the Pi via OS X Terminal.

    1. That Sorts it out.
      Thanks Mike

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