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by Nigel Day
Mon Feb 09, 2015 4:41 pm
Forum: General discussion
Topic: The Raspberry Pi 2 Q&A thread
Replies: 442
Views: 73508

Re: The Raspberry Pi 2 Q&A thread

I think the default flags mean that code compiled on a P2 will work on a P1. This seems to be the case: I have just compiled a test program on a Pi2, moved it to a B+, and it worked. I hope it is a long time before this changes - especially as I suspect that for most user programs the difference in...
by Nigel Day
Mon Feb 09, 2015 4:27 pm
Forum: General discussion
Topic: The Raspberry Pi 2 Q&A thread
Replies: 442
Views: 73508

Re: The Raspberry Pi 2 Q&A thread

@cacb: I have seen it mentioned that programs running on PI1 B/B+ will run just fine on the PI2. I have several PI1 machines and one of the issues is that compiling software can be very slow (cross-compilation is too advanced for me). If I buy a PI2 and install raspbian on it, then compiling C++ pro...
by Nigel Day
Mon Feb 09, 2015 1:30 pm
Forum: General discussion
Topic: The Raspberry Pi 2 Q&A thread
Replies: 442
Views: 73508

'real-life' performance comparison

Having just got my hands on a Pi2, I was interested in running a database performance test on it to see how the Pi2 compares in speed with a Pi B+. I prepared a new microSD card with the latest Raspian image, used apt-get update and upgrade to make sure I was really up to date (as of this morning), ...
by Nigel Day
Tue Apr 23, 2013 8:51 am
Forum: Python
Topic: pyodbc module
Replies: 9
Views: 6649

Re: pyodbc module

oops... cut & paste error; the last line of my build instructions for pyodbc for python3 should have said 'install', not 'build', viz: sudo python3 setup.py install Of course, you could combine the build and install into a single step - but as a matter of habit it is always best to minimise the work...
by Nigel Day
Mon Apr 22, 2013 6:31 pm
Forum: Python
Topic: pyodbc module
Replies: 9
Views: 6649

Re: pyodbc module

Hallo, has anybody python3 pyodbc 3.02 installed? I can not find it. python py odbc is available but not for python3 , did I overlook something? thks Both python2 and python3 are installed by default on the Raspian wheezy distro, and as you point out you 'sudo apt-get install python-pyodbc' you get...
by Nigel Day
Tue Apr 16, 2013 2:44 pm
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Re: Free real-time relational database for the Raspi

What are your ball-park commercial license prices for the full-version development and runtime? Pricing for Polyhedra Lite for Raspberry Pi for commercial applications has yet to be determined, but will be kept low. For non-commercial distribution, we want to be kept in the loop, but intend to gran...
by Nigel Day
Tue Apr 16, 2013 10:24 am
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Re: Free real-time relational database for the Raspi

Jim, as you say, it is unlikely that Polyhedra Lite would be used for a multi-user database on the Pi - but a multi-client database, that's another matter (especially as the clients could be on another Pi, or a Windows box or a Linux workstation). So some clients can be feeding readings into the dat...
by Nigel Day
Mon Apr 15, 2013 8:31 am
Forum: General discussion
Topic: Polyhedra database
Replies: 5
Views: 572

Re: Polyhedra database

Enea have built a version of Polyhedra for the Raspberry Pi, for use with the Raspbian distro. If anyone is interested in it for a different distro, drop me a PM. Polyhedra Lite is free (subject to some constraints of further distribution) and the documentation can be found at http://developer.polyh...
by Nigel Day
Sun Apr 14, 2013 12:27 pm
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Re: Free real-time relational database for the Raspi

Jim, I'm glad you were able to get Polyhedra lite working. Re the client-server model, it is in essence the same as that used by Oracle, SQL Server, MySQL, etc, so should be familiar to many people with database experience on Windows, Linux, and Solaris - but I realise those using the raspberry Pi m...
by Nigel Day
Sat Apr 13, 2013 6:24 pm
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Re: Free real-time relational database for the Raspi

I'll try not to give a marketing pitch here, but Polyhedra Lite is free as in beer for personal use, subject to some restrictions on distribution.* how does Polyhedra compare with SQLite? Well, unlike SQLite it is client-server; this protects your database from programming errors in your application...
by Nigel Day
Sat Apr 13, 2013 12:13 pm
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Re: Free real-time relational database for the Raspi

Polyhedra Lite is an in-memory SQL database system using the client-server model. It's a cut-down version of SQL, with some extensions (a) to allow you to 'derive' one table from another, and (b) to allow you to specify whether individual tables are persistent or transient. (Transient data is the st...
by Nigel Day
Fri Apr 12, 2013 12:00 pm
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Re: Free real-time relational database for the Raspi

Just unpack the tar.gz file for the Polyhedra release kit into, say, your home directory. Then you have a number of choices: probably the easiest is to copy the contents of poly8.7/linux/raspi/bin into your ~/bin directory, or put symbolic links to them in that directory: cd ~/bin ln -s ~/poly8.7/li...
by Nigel Day
Mon Oct 15, 2012 12:23 pm
Forum: General discussion
Topic: Free real-time relational database for the Raspi
Replies: 15
Views: 4396

Free real-time relational database for the Raspi

Polyhedra is a high-speed real-time database, used in embedded systems as diverse as cellular base stations, water treatment plants, and remote meter reading networks. A free version is now available for the raspberry Pi, for use on Raspian. Links to the downloads can be found on the http://www.enea...
by Nigel Day
Sat Aug 25, 2012 11:38 pm
Forum: General discussion
Topic: I made a Raspberry PI Laptop
Replies: 836
Views: 313023

Re: I made a Raspberry PI Laptop

Nigel Day said: By the way, where can I get a short - one to two foot, say - HDMI cable? I have this one (8 inches) on order, so I can't give a 'satisfactory' or 'unsatisfactory' verdict yet: http://www.amazon.com/Inch-Hdmi-Port-Saver-Cable/dp/B000Q6WEFW/ref=sr_1_1?s=electronics&ie=UTF8&qid=1345907...
by Nigel Day
Sat Aug 25, 2012 3:05 pm
Forum: General discussion
Topic: I made a Raspberry PI Laptop
Replies: 836
Views: 313023

Re: I made a Raspberry PI Laptop

Reading the thread has led me to believe I just need: The blackberry usb Y cable. some form of converter for that cable to connect it to the lapdock. An hdmi cable a converter for the hdmi cable to connect it to the lapdock. I use a blackberry cable ($3 from DealExtreme, http://dx.com/s/107901 ) a ...
by Nigel Day
Sun Aug 05, 2012 6:33 pm
Forum: Raspbian
Topic: A little help required
Replies: 10
Views: 946

Re: A little help required

Did you create a new user, or are you using the normal username "pi"? I created a new user and not the 'pi' one. To allow your new user to use sudo, you will have to update the file /etc/group. Look for the sudo line, and add a comma and your new username at the end. To allow your new user to use s...
by Nigel Day
Sun Aug 05, 2012 11:21 am
Forum: General discussion
Topic: I made a Raspberry PI Laptop
Replies: 836
Views: 313023

Re: I made a Raspberry PI Laptop

Aside, anyone know a easy way to create a keystroke shortcut to disable/enable the mouse? I find the huge touchpad way too sensitive when typing. Try double-tapping on the white LED at the top-left of the touchpad. The LED should go out, and the touchpad becomes unresponsive. Repeating the procedur...
by Nigel Day
Sat Aug 04, 2012 8:56 pm
Forum: General discussion
Topic: I made a Raspberry PI Laptop
Replies: 836
Views: 313023

Re: I made a Raspberry PI Laptop

http://www.amazon.com/gp/offer-listing/B003VWJT0G/ref=dp_olp_new?ie=UTF8&condition=new That cable states it is for charging two devices at one. It may not have the data lines in it. That's why in my original comment I mused about the skimpiness of the cable, and if it only provides power, that woul...
by Nigel Day
Mon Jul 23, 2012 1:31 pm
Forum: Raspbian
Topic: slow IP stack on Raspian?
Replies: 4
Views: 1907

Re: slow IP stack on Raspian?

sure! here it is: // ----------------------------------------------------------------------------------- // bounce time tester // // a simple little test program that sees how fast a short message can be sent from // one hand to another and back again, via UDP sockets. The aim is to get an idea // o...
by Nigel Day
Mon Jul 23, 2012 11:55 am
Forum: Raspbian
Topic: slow IP stack on Raspian?
Replies: 4
Views: 1907

Re: slow IP stack on Raspian?

That made a huge difference, thanks! using the reduced kernel the performance is now back up to almost where it was on Debian squeeze: 14143 rather than 15802 round trips per second. (I had hoped Raspian would be at least as fast, though!)
by Nigel Day
Mon Jul 23, 2012 11:09 am
Forum: Raspbian
Topic: slow IP stack on Raspian?
Replies: 4
Views: 1907

slow IP stack on Raspian?

I have a little test app, part of which sets up a UDP port and then pings small messages back and forth to get an idea of the IP stack performance. On the Debian squeeze release, I was getting over 15,000 round trips per second, but on Raspian this drops down to just over 9,000. Anyone got any ideas...
by Nigel Day
Sat Jun 16, 2012 3:37 pm
Forum: Automation, sensing and robotics
Topic: relay schematic
Replies: 5
Views: 2965

Re: relay schematic

I have a little Z-guage model railway I control via a Velleman K8055 USB interface board, using 5V sealed reed relays I got from my local Maplins (http://www.maplin.co.uk/sealed-reed-relays-2605) to trigger the turnouts. Clearly, I could use this set-up with my raspi (someone has already reported su...

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