Archive for the ‘Uncategorized’ Category

At my parents place, we installed photovoltaic cells. The produced electricity is converted to AC power and is coupled with the normal grid: if we produce too little, the grid provides the remaining power; overproduction is given to the grid.

The inverter (the device that converts DC into AC) is a SolarMax C-series. It has a 2-line LCD display that gives out some basic information: current, voltage, power; produced energy today, this month, this year, … This is very useful information, but is a bit hard to access. The instruction manual reveals that there is a computer interface available to read out its data. Naturally, I wanted to explore this!

Continue reading ‘SolarMax MaxTalk protocol reverse engineered’ »

I was bored of constantly looking for updates on a website. A little googling turned up this nice site. It turns (a part of) a webpage into an RSS feed. Here are the ones I created:

If I log in to my Ubuntu box over SSH from my MacOSX terminal, then start screen, my backspace-key doesn’t work anymore. Pressing it deletes the first character on the right of the cursor, instead of the one on the left. This only happens inside screen, not on the regular bash-shell.

I found different workarounds:

  • A forum post telling to change the terminal preferences to send backspase as CTRL-H (ASCII 0x08) instead of the normal ASCII 0x7f.
  • A blogpost telling to lie about the terminal you’re using: “TERM=screen screen”
  • Another blog telling to do remapping inside screen with bindkey-commands

None of the above worked without side-effects: CTRL-H is not understood by MacOSX terminal applications; bindkey-commands are applied even if I SSH from my linux box.

The solution I like best is to change the terminal from the standard “xterm-color” to “rxvt”. After this change, everything worked like a charm.

My previous system was a Linux-box. I made some adjustments to my keyboard in order to make it “better”. Since I use Vim a lot (apologies to Emacs-fans), the escape-key is doing overtime. On a normal keyboard however, the escape-key is located at the top left. Other keys are very near the main keyboard, but are hardly used. I almost never use the CapsLock key at all. So I switched both keys around, giving the CapsLock key the escape-function and the other way around.

Under Linux, you can remap keys using xmodmap. It seems that Windows has a similar feature, although much less documented. Here is a short summary of this article.

Continue reading ‘Remap keys under Windows’ »

I just found a very nice post describing nice things to do with Bluetooth. By using the Proximity tool, my MacBook Pro can monitor the precense of my cell phone. Proximity will run an AppleScript when a selected device enters and/or leaves Bluetooth range. Most  phones are class 2 Bluetooth devices, which gives a range of 10m (outdoors). This allows you to automatically lock your desktop when you leave and unlock when you come back.

Continue reading ‘Useful things to do with Bluetooth’ »

I was looking around to get my VIDEO_TS-directory burned to a DVD-R disc. Apparently, Burn does not support this. This hint seems to work:

hdiutil makehybrid -udf -udf-volume-name DVD_NAME -o MY_DVD.iso /path/to/VIDEO_TS/parent/folder

I just read an interesting article on how HFS+ deals with fragmentation. Not only will it take proactive steps to avoid fragmentation, apparently it will defragment some files on-the-fly.

This forensics-site has a very detailed article on the hex-dumps you can get from an HFS+ partition.

Our weather station has a serial connection and comes with Windows-software to view the weather data on your PC. The app is very eye-candy, but doesn’t do anything more than displaying the data. I’m more interested in long-term trending. So I wrote my own application to talk to the weather station and store the result in an rrdtool database.

Continue reading ‘Reverse engineering the Oregon WMR928NX weather station’ »

I’m again having problems with my new MacBook Pro (the late 2008 unibody one). The problem is most easily visible when BootCamping into Windows and running whatever 3D application (I use 3DMark06). Within 5 minutes, the machine crashes. After some trail-and-error, I found out that it appears to be a thermal problem.

Normally, when the load goes up, the fans kick in to keep the temperature down. Mine don’t… When stressing my CPU under MacOS, it happily goes up to 90ºC with the fans still idling at their standard 2000rpm. Needless to say, a bit of GPU-load increases the temperature beyond the safety-thresholds.

Resetting the SMC solves this problem only partially. On the first boot with a clean SMC, the same CPU-test brings the CPU to 70ºC with fans blazing at 4750rpm, as it should be. Once the machine goes through a sleep-wake cycle, the same test brings it straight up to 90ºC.

Just when I was about to call Apple Care, a software update pops in: SMC Firmware Update 1.2, looked promising, but the problem persisted… I’ll call Apple Care tomorrow.

Continue reading ‘Cooling problem with MacBook Pro’ »

Since PhotoShop is a bit too expensive, I’m sticking to The GIMP. When trying to get The GIMP to work under MacOSX (Leopard) I had two issues. The first one was a huge lag in the mouse pointer. Apparently this was caused by a specific version of X11. Since I’ve updated to 10.5.6, the problem disapeared by itself.

A second issue I was having is that (by default) the first mouse-click simply activates the window. The GIMP uses multiple windows, making this very anoying: to switch to another tool, I had to click twice. This blogpost gives the solution:

$ defaults write org.x.X11 wm_click_through -bool true