Raspberry Pi database, mongodb, Raspberry Pi
After purchasing a Raspberry Pi 2, I decided to move some of my projects to it. I also added an external 2.5 inch USB drive via a USB hub. I store various sensor information in a MongoDB database and needed everything to run on the R-Pi 2. I chose to stick with the well-supported Debian Linux port, Raspbian Wheezy, as opposed to ARCH Linux that I used on my old R-Pi B+, as the R-Pi 2 has a quad core ARMv7 processor that requires a new kernel.
UPDATE (30 January 2016): I’ve compiled MongoDB 3.0.9 and tools for R-Pi 2 Raspbian (Jessie). Check here.
UPDATE (25 December 2015): Instructions for compiling MongoDB 3.0.7 and tools for R-Pi 2 running Raspbian Jessie are now available. Check here.
UPDATE (8 November 2015): If you are running Raspbian Jessie, you can “apt-get install mongodb”. This will result in an install of MongoDB v2.4. Good enough for most uses and you get a working mongo shell 😉 If you want MongoDB v2.6.3, read-on!
I was back to hunting for a compatible MongoDB binary — or instructions on how to compile from source. Research showed that MongoDB does not compile for ARM after version 2.6.3 🙁 Searching the ‘net led me to the “facat’ blog.” This blog shows how to cross-compile MongoDB 2.6.3 for ARM. Precompiled binaries are also available. NOTE that the mongo shell does NOT work correctly on the R-Pi. “mongod”, the server, does work fine and can be accessed programmatically or via a mongo shell from another (non-R-Pi) computer. I use “mongo” on my Mac to connect to “mongod” running on the R-Pi 2.
more after the break
Unfortunately, I am hearing reports that MathTerms does not run under iOS 8. I had tested it with prerelease versions of iOS but it fails to load and run under the latest iOS 8.0.2. I am investigating and looking to fix…
In the meantime, I have suspended downloads from iTunes.
Unfortunately, I have not found a “quick-fix” for MathTerms for iPad. I would really like to rewrite and enhance much of it, to enable working on iPhones as well as iPads. Alas, I do not currently have the time to do this. My day-job is taking all my time and energy.
I’ll try to work on a new version during the holiday season. No guarantees 🙁
Raspberry Pi mongodb, nodejs
A while back, I compiled mongoDB 2.1 for Raspberry Pi based upon instructions found on other sites and kind work by developers sharing code on Github. I acquired a Raspberry Pi B+ and tried to compile mongoDB as I had done previously. I quickly found out that the (old) compiled version (2.1.1) no longer functions under Raspbian.
I had also been trying out Arch Linux for R-Pi as it was “lighter” and did not include all the GUI/X components that I don’t use. I use R-Pi for more server centric things and use frame buffer apps for video and images (omxplayer, fbi, fim).
I saw a comment to a posting when Googling for new info for mongoDB on R-Pi. It said, simply, “use Arch Linux”. So I did! I had a little trouble getting Arch Linux to run on the B+ but after a firmware update obtained by a “pacman -Syu” on a R-Pi model B, I could now boot and use Arch Linux on the R-Pi B+ 🙂
My effusive thanks go to the Arch Linux Package maintainers!
Raspberry Pi Raspberry Pi
I’ve been asked in emails and comments about what software I use on my 1942 Crosley Radio-Pi project.
I use the recommended Raspbian distro of Linux based on Debian Wheezy. I normally do not start or use the GUI/X. Many Raspberry Pi users use a Linux distro oriented around XBMC such as OpenELEC or Raspbmc. XBMC is a software media player that allows users to play and view most videos, music, podcasts, and other digital media files from local and network storage media and the internet.
While I have a Logitech K400 keyboard with touchpad attached via a USB dongle for “local” use, I almost always ssh into the R-Pi from my Mac. The Radio-Pi is connected to my home Wi-Fi network via an Edimax EW-7811UN Wi-Fi USB adapter (US$10 at Amazon).
More info on my frequently used apps and utilities after the break. More
Raspberry Pi Raspberry Pi
A while back, I saw a picture online of a restored antique radio that caught my attention. The accompanying post described the process of restoration. I’m not into radio restorations but I think the old wood radio cases are very “cool”. I also recently contributed to a Kickstarter project for HDMIPi, an “affordable 9 inch High-Def screen for the Raspberry Pi”. I thought that I might place the screen and R-Pi inside an old radio case.
After looking on eBay and craigslist, I could not find a suitable enclosure for the HDMIPi and paper mockups showed the screen to be a bit small at a distance. I used my old original iPad as a test device for measurements and viewing. I liked the viewing and pixel size of this its screen.
Well, the HDMIPi was going to be slow in coming (still is) and I saw (fairly) inexpensive 1024 X 768 iPad displays and driver boards on eBay. I also found a old 1942 Crosley radio case that had a front cut-out that was very close to the iPad screen size. The radio portion was not fixable so the case was reasonably “priced”. I bid on it … and won. I then had yet another project demanding time 😉
Uncategorized iPad, MathTerms
I was perusing Apple iOS documentation the other day and thought I’d check my “Sales and Trends” graphs for MathTerms for iPad. Downloads have been pretty flat for the last year as I have not updated or promoted MathTerms 1.x. Much to my surprise, on May 13, 2014, there were over 50,000 downloads!
I consulted Google and Bing to see if I could determine what caused this spike. The only significant event I could find was a mention of MathTerms on Pinterest. SO… I’m not sure if this social media mention was the cause or if it was something else.
In any case, I hope the App is helping students, teachers and/or parents 😉
Android Android, MathTerms
I *finally* finished my port of MathTerms for “generic” Android devices. I had previously done specific implementations for Amazon Kindle Fire and B&N Nook but now have a version for Android tablets and high-resolution smart phones. I reworked the layout code to detect screen resolution and orientation — to provide better layout and legibility. I also updated a few definitions based upon user feedback
Please check it out and download from Google play.
Raspberry Pi database, mongodb, Raspberry Pi
I’ve been looking at noSQL databases in conjunction with Node.js. I have several Raspberry Pis that I have been using as development and test platforms. I have had good success with couchDB but have seen more examples and deployments using mongoDB. MongoDB is clearly developed on Intel processors but has been ported to non-Intel processors with different “endian”. Getting mongoDB to compile and run on a Raspberry Pi has been a challenge — as seen by the dearth of info when Googling. I did run across a couple of useful sites with links and directions on how to compile mongoDB on the R-Pi BUT both had a few problems. I’ve managed to get mongoDB version 2.1.1 working. Specific instructions — More
There has been a lot of press coverage and law-suits flying over app privacy concerns and data usage. MathTerms does not currently (in version 1.x) include a policy inside the app or on associated Help pages. Very simply put, MathTerms collects NO data on usage and has NO internet connection. I do not collect any data in any form. MathTerms does have a few links to external sites for app support and to credit content creators. These links bring up web pages in a web view but do not convey any information in doing so.
I did a quick look at download statistics for MathTerms at iTunes, Amazon and Barnes and Noble. I was way surprised! I expected many downloads for iPad and not so much for Android. Turns out that Barnes and Noble Nook users downloaded it over 5,000 times in December and over 25,000 times in the the last 5 months. These numbers are very comparable to iPad installs. Amazon Appstore installs were way behind the others.
I hope you find the MathTerms app useful. While I do not have any immediate plans for an update, I welcome comments and suggestions