Skip to content

Matlab’s .fig figure files: how not use them!

Note to self.

Do not save images as Matlab .fig files, then come back to them a year later and expect them to be editable! A much better idea is to save the script that generates the plots instead! At least this way if you don’t have Matlab then you can recover the data manually, or use Octave.

Better ATI graphics driver install

After having more problems installing the proprietary driver for my HD4710 ATI graphics card, a forum post pointed me towards a tool named SMXI. This will automate the dist-upgrade of your system, but more importantly, is a simple way to install the current fgrlx drivers without any weird performance issues!

Also note that for crunchbang linux I had to use “radeon.powersave=0″ as a boot parameter rather than the normal nomodeset.

DigiKam: PNG’s with EXIF content

Another quick note just in case anyone is searching for PNG EXIF information in DigiKam. I’ve just found that officially, PNG does not support EXIF data, google it. (Another waste of time). I’ve found that most of the time, it seems to work. I’m not sure if this is just an internal DigiKam thing, since sometimes, no matter what I do, the EXIF data does not get saved in the PNG.

So…, once again I am back to just keeping the RAW’s and making jpegs, just to keep the EXIF info intact. What a pain.

Using paper as a PCB exposure masking medium

I normally use OHP transparencies (acetate) for my PCB masking, but after running out I wanted to find something cheaper (from staples a pack of inkjet transparencies costs approximately £20!). I wanted to try and use paper, since it’s essentially free (everyone has it) and I wouldn’t have to go out and buy more stuff!
So, after a bit of searching, I found that a few people had mentioned using paper, but provided no results. They mentioned using two methods: just raw paper, and transparent’ised paper. To do this I used oil (another essentially free product. This involves taking the paper (after it has been aligned on the PCB) and gently rubbing oil into it. You are aiming for the paper to be essentially dry’ish to touch, with the paper absorbing most of the oil. Try to make it as consistent as possible (from the colour) as oil/non-oiled areas can cause problems.

The image below shows the results:
Using paper as a PCB exposure masking medium
From the left, these are my test exposures with mask developing but no etching. We can see that if we wanted to use just plain paper, we would have to expose for much longer than 5 minutes. The oil soaked paper worked better, with 5 minutes showing ok results.
The PCB in the middle was my first attempt using raw paper, with a UV exposure time of 15 minutes. We can see that the results are ok, but there are many shorts. A longer exposure and less air gaps in the mask would help here. The final PCB on the right is oil soaked paper with an exposure time of 6 minutes. Results are very good except for a few shorts.

Conclusions: Oil soaked paper works pretty well, considering the cost. I’ll try and perfect this technique next time.

Note that my exposure box seems to require much longer exposure times that everyone else’s, so test yours at a lower exposure time first. Also, the marks on the rightmost PCB are from my clamp when cutting (too tight!). These will come out when I buff the UV sensitive mask off.

I don’t really use this any more

Well, as it turned out, I don’t really use this as much as I thought I would. The main reason was that I don’t have enough time to do stuff let alone write about it!
I am keeping the old content though, for posterity’s sake.
If I ever get around to doing something interesting, they I may post it here.

Phil

Network problems - Static IP and DHCP

Latest ubuntu ball-ache started when I wanted my wireless network to use DHCP and the ethernet to use a static address.
Continue reading ›

Streaming to the XBox - Using Fuppes

I’ve now moved back to Kubuntu, and I am sure that I am going to stay.

Nearly top of the list is to get my XBox streaming back up and running. This post details my Fuppes installation process and thoughts. Initial thoughts is that this doesn’t look very mature. There is no GUI and it was a pain to install. I still haven’t tested with the XBox yet.

Installation:

I used this tutorial from the ubuntu forum to install fuppes.

The largest problems came from 1) the program is shockingly designed and 2) the config files need to be spot on or they don’t work at all. Here are my (mostly) working config files.

fuppes Configuration file

fuppes vfolder configuration file

The only thing left to do now is to get it to automatically start, but there are lots of posts about that, and its not a priority.

ATI HD 4730 Ubuntu/Kubuntu on Karmic 9.10

I’ve had major problems getting the newest ATI drivers, both proprietary and open source. Black screens, freezes, everything.

The solution (so far) is to use an older ATI Catalyst driver. I have tested up to 9.12 to be working. Download, sudo sh -i ***.run, sudo aticonfig –initial -f, restart, sudo amdcccle, to setup. Done.

XBox Windows 7 Problems

Having problems where I couldn’t see the xbox on the network.

Turns out that all I had to do was disable the SSDP discovery service and the Upnp service that comes with it.  That

xBee ZNet 2.5 ongoing serial problem fixed

I have had an ongoing problem with the xBee’s for some time. It goes something like this:

Setup:
xBee ZNet 2.5 in API mode using sleep’s.

Problem:
Periodically (aren’t they always the worst!) the xBee would not perform some of the functions that I asked it to. For example, it did not like sending AT commands after a reset, sometimes it would miss vital transmit requests.

Solution:
When using sleep mode, some nasty characters are left in the xBee’s buffer when coming in/out of sleep mode. This would cause the next command to not function properly. To fix, always transmit a “\n” (I.e. line feed) before you transmit a command. Eg. somewhere just before you transmit your data from the UART, stick a your_tx_routine(”\n”) in.