I was trying to plan a family cycling trip in a rush this morning and struggling to find a map to
use (opencyclemap is no good because I like to go to un-mapped places so I can add them to the map).
I finally remembered that ages ago I wrote a little javascript application to display an Ordnance Survey map, and let you put route markers on it which you can then put onto a Garmin GPS receiver to use for navigation - I used that to record where I intended to go, so I knew where there was supposed to be a bridleway...
Anyway I thought I should add that program to my repository in case anyone else is interested. There are a few things to do to it - see the README file in the repository directory - The source code is in my ntmisc code repository under gpxedit.
You can find the program working at http://www.maps.webhop.net.
I will do a bit more work on this when I get chance. I always intended to convert it to OpenLayers rather than multimap's proprietary API, and at the moment you have to copy and paste the GPX file into a text editor to get around the irritating web browser security - need a way of getting around that - the simplest would be to add an 'echo' server side application that would allow you to download the GPX file from the server, but that feels like brute force and ignorance!
Sunday, 7 March 2010
Wednesday, 17 February 2010
Android Development on Ubuntu
I just got an LG GW620 android mobile phone. I want to use it for mapping (http://www.openstreetmap.org). There is an android editor called Vespucci available, but it needs some work to make the UI easier to use. I thought I would have a look at the source code to see if I can work out how to modify it.
The android developer web site says that it is best to use the Eclipse IDE, but when I tried I got all sorts of errors about un-satisfied dependencies.
Fortunately someone had posted some instructions to get it working on Ubuntu (http://ubuntuforums.org/showthread.php?p=8842292#post8842292).
Now I have followed this I have a working IDE to develop Android applications, and have got a basic "Hello World" application working. I have also downloaded and complied the Vespucci source code, and run it on the SDK emulator.
Just need to understand how Android UIs work now....
The android developer web site says that it is best to use the Eclipse IDE, but when I tried I got all sorts of errors about un-satisfied dependencies.
Fortunately someone had posted some instructions to get it working on Ubuntu (http://ubuntuforums.org/showthread.php?p=8842292#post8842292).
Now I have followed this I have a working IDE to develop Android applications, and have got a basic "Hello World" application working. I have also downloaded and complied the Vespucci source code, and run it on the SDK emulator.
Just need to understand how Android UIs work now....
Sunday, 14 February 2010
Progress Mapping Hartlepool
Benjamin and I are making progress mapping Hartlepool for OpenStreetMap.
I have just run a query on my database to see how many kilometers we must have cycled to produce the map. I was really quite shocked that it was over 550 km! No wonder I am tired...
Progress with the map and the breakdown of the distances are shown on the Hartlepool OpenStreetMap page.
I have just run a query on my database to see how many kilometers we must have cycled to produce the map. I was really quite shocked that it was over 550 km! No wonder I am tired...
Progress with the map and the breakdown of the distances are shown on the Hartlepool OpenStreetMap page.
Tuesday, 2 February 2010
Townguide Web Service Working
Well, I think the townguide web service is working now (http://www.townguide.webhop.net).
There is a simple queue so it only renders one job at a time, and you can view the progress of your job through the queue.
The source code and early documentation is stored at http://code.google.com/p/townguide.
The main thing to fix now is the output resolution - if I increase the resolution (in dpi) of the output map too far, mapnik changes zoom level and reduces the size of the text, so it is no easier to read - I need to understand mapnik style sheets now....
There is a simple queue so it only renders one job at a time, and you can view the progress of your job through the queue.
The source code and early documentation is stored at http://code.google.com/p/townguide.
The main thing to fix now is the output resolution - if I increase the resolution (in dpi) of the output map too far, mapnik changes zoom level and reduces the size of the text, so it is no easier to read - I need to understand mapnik style sheets now....
Sunday, 3 January 2010
Town Guide Progress
The good thing about so much bad weather over Christmas was that I could do some nerdy work rather than going out walking or cycling.....
The town guide Python project has therefore made good progress. The program can now generate a PDF 'poster' that can include a street index, and labelled features from the map database (pubs, shops, tourist attractions etc.). A typical example is shown at http://www.townguide.webhop.net/example1_hartlepool.pdf.
I have set up a very rudimentary web service using a PHP script to call townguide.py to generate a town guide on demand at http://www.townguide.webhop.net. It is running on a very small computer, and there is no queue, so there is no saying what will happen if more than one person tries to use it at once - that is another job!
The town guide Python project has therefore made good progress. The program can now generate a PDF 'poster' that can include a street index, and labelled features from the map database (pubs, shops, tourist attractions etc.). A typical example is shown at http://www.townguide.webhop.net/example1_hartlepool.pdf.
I have set up a very rudimentary web service using a PHP script to call townguide.py to generate a town guide on demand at http://www.townguide.webhop.net. It is running on a very small computer, and there is no queue, so there is no saying what will happen if more than one person tries to use it at once - that is another job!
Tuesday, 15 December 2009
Animation
Laura and I have been experimenting with stop-motion animation - set up a camera on a tripod with a remote shutter release, then position a scene in front of it, and change it by a very small amount between shooting frames.
10 frames per second seems to work ok for what we are doing (and you get more video for your money, so it is a bit more rewarding!).
I am using mencoder to turn the jpeg images from the camera into a mpeg4 video using the following:
This produces an mpeg4 encoded .avi file, scaled to 640x480 pixels.
You can then run mencoder again to add a mp3 audio stream.
The results can be seen at http://flickr.com/jones139.
10 frames per second seems to work ok for what we are doing (and you get more video for your money, so it is a bit more rewarding!).
I am using mencoder to turn the jpeg images from the camera into a mpeg4 video using the following:
mencoder mf://*.JPG -mf fps=10 -o leaves.avi -ovc lavc -lavcopts vcodec=msmpeg4v2:vbitrate=800 -vf scale=640:480
This produces an mpeg4 encoded .avi file, scaled to 640x480 pixels.
You can then run mencoder again to add a mp3 audio stream.
The results can be seen at http://flickr.com/jones139.
Sunday, 29 November 2009
Town Guide (again)
Progress with the Town Guide program stalled a bit when I went on holiday, then was rather busy at work for a while. I am back to thinking about it now.
The current version has two output modes, HTML and PDF - both are quite crude, but work.
The PDF output uses LaTeX, which seemed like a good idea at the time, but I am struggling because LaTeX thinks it knows better than me what the output is supposed to look like - it keeps putting the tables etc. at the end, rather than where I ask for them.
This means I have two options - either do battle with LaTeX to sort it out, or abandon it and go for a more 'direct' PDF production.
I think that as the output I am producing is short and simple, I may as well go for 'direct' production. I am going to have a try with ReportLab's python library (http://www.reportlab.org/oss/rl-toolkit/guide/).
I'll go and read the instructions and see how it goes....
The current version has two output modes, HTML and PDF - both are quite crude, but work.
The PDF output uses LaTeX, which seemed like a good idea at the time, but I am struggling because LaTeX thinks it knows better than me what the output is supposed to look like - it keeps putting the tables etc. at the end, rather than where I ask for them.
This means I have two options - either do battle with LaTeX to sort it out, or abandon it and go for a more 'direct' PDF production.
I think that as the output I am producing is short and simple, I may as well go for 'direct' production. I am going to have a try with ReportLab's python library (http://www.reportlab.org/oss/rl-toolkit/guide/).
I'll go and read the instructions and see how it goes....
Sunday, 4 October 2009
Free Town Guide
For ages I have been intending to write a program to produce a nice guide to a town or area based on OpenStreetMap data.
I finally decided that I knew enough about postgresql and python to have a go.
The result is a program called townguide.py. The idea is that you load the openstreetmap data into a postgresql database (like you do if you want to render it using Mapnik), then produce an xml file to tell townguide.py what you want rendering. It then goes and produces the nice output for you.
Version 0.1 is working and is on SVN. At the moment it only produces html output (because that is easy), and it is not very pretty.
The next stage is to make it produce postscript to give nice printable output on a defined paper size.
An example of the html output is at http://hartlepoolmap.webhop.net.
Having looked at the output it looks like it will be quite useful from a mapping point of view - if you know the area you can review the features that are summarised and look for missing banks, supermarkets etc.
I finally decided that I knew enough about postgresql and python to have a go.
The result is a program called townguide.py. The idea is that you load the openstreetmap data into a postgresql database (like you do if you want to render it using Mapnik), then produce an xml file to tell townguide.py what you want rendering. It then goes and produces the nice output for you.
Version 0.1 is working and is on SVN. At the moment it only produces html output (because that is easy), and it is not very pretty.
The next stage is to make it produce postscript to give nice printable output on a defined paper size.
An example of the html output is at http://hartlepoolmap.webhop.net.
Having looked at the output it looks like it will be quite useful from a mapping point of view - if you know the area you can review the features that are summarised and look for missing banks, supermarkets etc.
Saturday, 19 September 2009
Using a Graphics Tablet in Ubuntu 9.04
I have a cheap Trust graphics tablet that I used to use for drawing in Inkscape or Gimp.
It stopped working at some point (Can't remember which Ubuntu version), but I decided I needed to use it again, because drawing with a touchpad on a laptop is a pain in the thumb...
It was surprising that it didn't just work when you plug it in, because I'm sure a previous version of Ubuntu behaved like this.
I found the instructions at https://help.ubuntu.com/community/AiptekTablet.
You basically have to install the Aiptek xorg driver and put a configuration file in a directory under /etc/hal. I wondered where the X11 configuration was now that Xorg.conf is so small....
Anyway, it works now...
It stopped working at some point (Can't remember which Ubuntu version), but I decided I needed to use it again, because drawing with a touchpad on a laptop is a pain in the thumb...
It was surprising that it didn't just work when you plug it in, because I'm sure a previous version of Ubuntu behaved like this.
I found the instructions at https://help.ubuntu.com/community/AiptekTablet.
You basically have to install the Aiptek xorg driver and put a configuration file in a directory under /etc/hal. I wondered where the X11 configuration was now that Xorg.conf is so small....
Anyway, it works now...
Sunday, 6 September 2009
Progress with IP Camera Viewer
The Edimax IP Camera seems to work fairly well, but the video stream seems to get interrupted every now and again, which makes the player crash - vlc just hangs, and mplayer exits.
I decided that exiting was better so I have written a simple pyGTK front end for mplayer to play the screen. It also includes a wireless network link quality monitor to help understand why it is not working - it is here as 'bentv'.
Note that bentv uses a library that I have started work on (named ntpylib for want of a better name) - so far it only contains one class, 'prefs', which deals with saving and loading of simple key/value data from XML files. It includes a dialog box that GUI programs (such as bentv.py) can use to allow the user to edit the data. prefs.py and prefs.glade need copying or linking into the bentv directory to make it work - there is no clever installer!
I decided that exiting was better so I have written a simple pyGTK front end for mplayer to play the screen. It also includes a wireless network link quality monitor to help understand why it is not working - it is here as 'bentv'.
Note that bentv uses a library that I have started work on (named ntpylib for want of a better name) - so far it only contains one class, 'prefs', which deals with saving and loading of simple key/value data from XML files. It includes a dialog box that GUI programs (such as bentv.py) can use to allow the user to edit the data. prefs.py and prefs.glade need copying or linking into the bentv directory to make it work - there is no clever installer!
Sunday, 23 August 2009
Embedded Linux Firmware Binary Files
I have always struggled to understand the format of the binary files that store the firmware upgrades.
They tend to be a mixture of some simple text labels, a kernel image and one or more mountable filesystems.
I have written a little script that goes through a file in a brute force (one byte at a time) way and attempts to mount it as various filesystem types (script stored here).
I used the information found by this script, and the source code provided by Edimax to work out some information about the internals of the IC-3010WG IP Camera - it is written up here.
They tend to be a mixture of some simple text labels, a kernel image and one or more mountable filesystems.
I have written a little script that goes through a file in a brute force (one byte at a time) way and attempts to mount it as various filesystem types (script stored here).
I used the information found by this script, and the source code provided by Edimax to work out some information about the internals of the IC-3010WG IP Camera - it is written up here.
Saturday, 22 August 2009
Practical Experience using the Edimax IP Camera
We were away on holiday last week so I got to try using the Edimax IP camera 'for real' as a monitor to keep an eye on our disabled son - known as 'BenTV-ng' (next generation) to distinguish it from 'BenTV' which was the old analogue system I used to use.
I gave up on using ad-hoc networking and instead took my wireless access point with me. This had the added advantage of improving the range of transmission because I could arrange for the access point to be between the camera and the computer. The computer I used was a Toshiba netbook running Ubuntu Linux.
The first thing I noticed was that when I powered everything up, nothing happened. At first I thought it was because the access point needed to see a wired connection as well as a wireless one, because when I connected the computer to it using a wire things started to work. I soon realised that the range was awful - it stopped working as soon as you were outside of his room. This turned out to be my fault because I had also switched on the analogue camera, which transmitted on the same frequency as the wireless network, so the noise level was huge. Things got better when I switched off the analogue camera.
At first everything appeared to work - vlc rtsp://admin:1234@bentv/ipcam.sdp played the video stream with sound.
I soon noticed that if the network got interrupted vlc froze, giving an apparently good picture, but no movement, which was no use to me. Instead I changed to mplayer - at least if that got into trouble it crashed and closed the video playback window so you knew something was wrong.
I set up a simple shell script that loops indefinitely starting mplayer then when mplayer exits it re-boots the ip camera, waits for 30 seconds and starts mplayer again.
This approach worked pretty well - the 30 second interruptions during the re-boot were not usually too troublesome.
We did find some problems when the video stream only worked for a few seconds before mplayer exited and the re-boot sequence started again, which was no good at all. The only way I found to cure this was to power off the camera all together - a software re-boot via the web interface did not cure it. I'll set up a little test at home now to see how long it takes to get into this state, and whether it makes a difference if you use wireless or wired networking.
The code to achieve this is stored at http://code.google.com/p/ntmisc/source/browse/bentv/.
The most up to date information I have on using this camera with linux can be found at http://ic-3010wg.webhop.net.
I gave up on using ad-hoc networking and instead took my wireless access point with me. This had the added advantage of improving the range of transmission because I could arrange for the access point to be between the camera and the computer. The computer I used was a Toshiba netbook running Ubuntu Linux.
The first thing I noticed was that when I powered everything up, nothing happened. At first I thought it was because the access point needed to see a wired connection as well as a wireless one, because when I connected the computer to it using a wire things started to work. I soon realised that the range was awful - it stopped working as soon as you were outside of his room. This turned out to be my fault because I had also switched on the analogue camera, which transmitted on the same frequency as the wireless network, so the noise level was huge. Things got better when I switched off the analogue camera.
At first everything appeared to work - vlc rtsp://admin:1234@bentv/ipcam.sdp played the video stream with sound.
I soon noticed that if the network got interrupted vlc froze, giving an apparently good picture, but no movement, which was no use to me. Instead I changed to mplayer - at least if that got into trouble it crashed and closed the video playback window so you knew something was wrong.
I set up a simple shell script that loops indefinitely starting mplayer then when mplayer exits it re-boots the ip camera, waits for 30 seconds and starts mplayer again.
This approach worked pretty well - the 30 second interruptions during the re-boot were not usually too troublesome.
We did find some problems when the video stream only worked for a few seconds before mplayer exited and the re-boot sequence started again, which was no good at all. The only way I found to cure this was to power off the camera all together - a software re-boot via the web interface did not cure it. I'll set up a little test at home now to see how long it takes to get into this state, and whether it makes a difference if you use wireless or wired networking.
The code to achieve this is stored at http://code.google.com/p/ntmisc/source/browse/bentv/.
The most up to date information I have on using this camera with linux can be found at http://ic-3010wg.webhop.net.
Friday, 24 July 2009
Ad-Hoc Wireless Network Troubles
Now that I have the Edimax IP Camera working I want it to connect to my Toshiba NB100 netbook computer as simply as possible - the idea is to use it when we are away on holiday so I don't want to have to set up a whole network with an access point etc. Instead I just want to set up an ad-hoc network between the computer and the IP Camera.
According to the instructions this should be easy - I tell the IP Camera to connect to an ad-hoc network called 'bentv', and then use NetworkManager in the Ubuntu desktop of the netbook to create the ad-hoc network.
This works fine on my main laptop, but fails on the netbook.
It turns out that NetworkManager is not capable of putting the wireless card into ad-hoc mode.
The work around was to have the script to start the VLC viewer shutdown network manager and set up the network manually as follows:
This is based on information I found here.
This seems to work, but the wireless networking is a bit iffy after the script exits - I might have to do the wlanconfig destroy bit again to put it into infrastructure mode.
According to the instructions this should be easy - I tell the IP Camera to connect to an ad-hoc network called 'bentv', and then use NetworkManager in the Ubuntu desktop of the netbook to create the ad-hoc network.
This works fine on my main laptop, but fails on the netbook.
It turns out that NetworkManager is not capable of putting the wireless card into ad-hoc mode.
The work around was to have the script to start the VLC viewer shutdown network manager and set up the network manually as follows:
#!/bin/sh
/etc/init.d/NetworkManager stop
ifconfig ath1 down
wlanconfig ath1 destroy
wlanconfig ath1 create wlandev wifi0 wlanmode adhoc
iwconfig ath1 essid bentv
iwconfig ath1 channel 1
iwconfig ath1 192.168.1.35
iwconfig ath1 netmask 255.255.255.0
ifconfig ath1 up
vlc --fullscreen rtsp://192.168.1.17/ipcam.sdp
/etc/init.d/NetworkManager start
This is based on information I found here.
This seems to work, but the wireless networking is a bit iffy after the script exits - I might have to do the wlanconfig destroy bit again to put it into infrastructure mode.
Sunday, 12 July 2009
More on Edimax IP Camera
I think we're getting somewhere. Searching around for references to IP cameras and mplayer yielded this thread which suggested the following:
Progress!
Just need to get sound working now....
Well, I did a bit more hunting around in the camera web set-up and realised I had missed a section about RTSP. The default was for RTSP to be enabled on port 554 with a rtsp path of ipcam.sdp.
When I tried
I got pictures AND sound!
I had tried rtsp before, but had missed the ipcam.sdp bit. Mplayer complains that my little netbook is too slow to play the stream, so there is a bit more work to do, but it looks promising. I'll try VLC now.
The most up to date information I have on using this camera with linux can be found at http://ic-3010wg.webhop.net.
This seems to work ok - there is a bit of a delay in the video, but probably ~0.1 sec, which is acceptable.
mkfifo fifo.mpeg4
wget -q http://admin:1234@192.168.1.117:4322 -Ofifo.mpeg4 &
mplayer -V -demuxer 35 fifo.mpeg4
Progress!
Just need to get sound working now....
Well, I did a bit more hunting around in the camera web set-up and realised I had missed a section about RTSP. The default was for RTSP to be enabled on port 554 with a rtsp path of ipcam.sdp.
When I tried
mplayer rtsp://192.168.1.117:554/ipcam.sdp
I got pictures AND sound!
I had tried rtsp before, but had missed the ipcam.sdp bit. Mplayer complains that my little netbook is too slow to play the stream, so there is a bit more work to do, but it looks promising. I'll try VLC now.
The most up to date information I have on using this camera with linux can be found at http://ic-3010wg.webhop.net.
Saturday, 11 July 2009
Edimax IC-3010Wg yet again
Still struggling with my IP Camera. Although mplayer can sort of play the mp4 stream, it does not seem reliable and takes a long time to start to play, so I do not think it is working correctly. I think I'll try the Edimax support, but have upgraded from version 1.20 to 1.25 of the firmware first, because they are bound to ask if I am using the latest software....
Thursday, 9 July 2009
Edimax IC-3010Wg again
I have made a bit more progress getting my Edimax IP Camera working, and detailed what I have learned at http://ic-3010wg.webhop.net.
The main problems are still that although I can download an MPEG4 stream using wget, neither mplayer nor vlc will play it directly, which is no good.
The other issue is that sound still does not work.....
The main problems are still that although I can download an MPEG4 stream using wget, neither mplayer nor vlc will play it directly, which is no good.
The other issue is that sound still does not work.....
Tuesday, 7 July 2009
Edimax IC-3010Wg IP Camera and Linux
I have just got an Edimax IC-3010Wg IP Camera. I intend to use it as a replacement for the analogue video system we use to keep an eye on our disabled son.
I was rather disappointed to find that it does not work with Firefox - you need an Internet Explorer ActiveX control to view the video images. This means it will not work on my Linux computers as supplied by the manufacturer.
What works:
The most up to date information I have on using this camera with linux can be found at http://ic-3010wg.webhop.net.
I was rather disappointed to find that it does not work with Firefox - you need an Internet Explorer ActiveX control to view the video images. This means it will not work on my Linux computers as supplied by the manufacturer.
What works:
- The camera gets its network configuration by DHCP (despite what the quick start guide says) so by checking the DHCP deamon log you can find its IP address.
- You can access its configuration screen with a web browser (default username admin, password 1234)
- Receive a snapshot picture using http://
/snapshot.jpg - Download a mjpeg video stream using wget http://admin:1234@192.168.1.117/mjpg/video.mjpg. (I don't know how to display this in real time though - mplayer doesn't seem to work).
- Some other things are detailed here.
- Someone has written a tcl application that works with a similar camera, but not this one (see here).
The most up to date information I have on using this camera with linux can be found at http://ic-3010wg.webhop.net.
Re-Programming MusicPal
I have not made any progress with the MusicPal since Christmas, but someone else has been busy and made a good start on some alternative software to run on it, which he has published here http://musicpal.v3v.de/.
Well done Marco - you have got much further than I have!
Giles also made progress with sound output and left his code in a comment to one of my earlier posts here.
Maybe it would be worth starting a project on Google Code or somewhere so other people can help develop it?
Well done Marco - you have got much further than I have!
Giles also made progress with sound output and left his code in a comment to one of my earlier posts here.
Maybe it would be worth starting a project on Google Code or somewhere so other people can help develop it?
Sunday, 28 June 2009
A General Purpose Network Solver?
I often get frustrated if I want to solve a simple fluid flow or thermal problem that is in the form of a network with branches, parallel paths etc. These tend to be a bit to difficult for a "back of the envelope" solution, which is always my preferred approach, so you end up writing code to iterate to find solution.
The easy way would be to use a commercial package like Aspen Hysis, SINDA or ESATAN, but these are very expensive for the once a year or thereabouts that I need to solve something like this. It would be nice to have a simple, low cost solver available.
I thought there would be plenty of open source ones available, but I have not been able to find a simple network solver, so I am going to resort to writing it myself. I did do one once before, but I seem to have lost the source code....It never got finished properly anyway.
I have started the project at http://code.google.com/p/openproc. There is no code worth talking of there yet, but the Wiki describes the sort of design I am thinking of. Any offers of help greatly appreciated!
The easy way would be to use a commercial package like Aspen Hysis, SINDA or ESATAN, but these are very expensive for the once a year or thereabouts that I need to solve something like this. It would be nice to have a simple, low cost solver available.
I thought there would be plenty of open source ones available, but I have not been able to find a simple network solver, so I am going to resort to writing it myself. I did do one once before, but I seem to have lost the source code....It never got finished properly anyway.
I have started the project at http://code.google.com/p/openproc. There is no code worth talking of there yet, but the Wiki describes the sort of design I am thinking of. Any offers of help greatly appreciated!
Tuesday, 9 June 2009
More Ubuntu 9.04 Sound Problems
I 'accidentally' wrecked my gnome desktop (no menus, toolabrs etc.) - I had been doing a bit of tidying up and must have uninstalled something important. I could not decide what, so re-installed the whole ubuntu-desktop package.
This came with pulseaudio again, so sound stopped working like last time.
Decided to invest an hour in sorting it. No real success searching on the web, but I did find this article - http://ubuntuforums.org/showthread.php?t=962695. The author provided a little script to update the ALSA drivers automatically, and quite a few people reported that this cured the sound for them.
I am always wary about running unknown programs as root, but the script looked safe enough - just an automated way of downloading the ALSA source packages and running 'make install' etc. so I trusted it.
It ran and it installed ALSA 1.0.20, compared to version 1.0.18 in the Ubuntu package.
To my surprise, when I re-booted the computer, sound is back!
This came with pulseaudio again, so sound stopped working like last time.
Decided to invest an hour in sorting it. No real success searching on the web, but I did find this article - http://ubuntuforums.org/showthread.php?t=962695. The author provided a little script to update the ALSA drivers automatically, and quite a few people reported that this cured the sound for them.
I am always wary about running unknown programs as root, but the script looked safe enough - just an automated way of downloading the ALSA source packages and running 'make install' etc. so I trusted it.
It ran and it installed ALSA 1.0.20, compared to version 1.0.18 in the Ubuntu package.
To my surprise, when I re-booted the computer, sound is back!
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