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Category Archives: Electronics

Colorhug build

The other parts for a Colorhug already arrived, and we got the missing color sensor TCS3200D, from Mouser last week. Please don't laugh at my SMD soldering skills I made a first PCB using the original pcb-layout from the git repo, but the combination of a printer driver that produced a fuzzy mask and less [...]

Another Nokia N9 vs. Garmin GPS test

These results are much like my previous ones. Close to buildings or other difficult places the N9 GPS performs significantly worse than the Garmin. This is somewhat surprising since the N900 performs very similar to a Garmin. Could better GPS-data on the N9 be just a software-update away? When is someone going to try to [...]

ColorHug parts

An order from RS delivered today with parts for a ColorHug, a device for color-calibrating your monitor. The circuit is based on the TCS3200D color-sensor which RS had on their website when I made the order, but the delivery note lists the parts as "discontinued". So these have to be sourced from somewhere else.

Nokia N9 vs. Garmin Edge 800 GPS Test

My legs aren't exactly recovered from Saturday's marathon, but a slow 5k jog anyway today. Sports Tracker was released for the N9 last week (or was it earlier?), so I thought I'd do some GPS testing. Held Garmin Edge 800 in my right hand and the N9 in my left. The results aren't that great [...]

Jacob's Ladder

Cropped from original like this: #!/bin/sh mencoder video.mp4 -oac pcm -o test.avi -ovc lavc -lavcopts vcodec=msmpeg4v2:vpass=1:vbitrate=5160000 -vf crop=370:300:200:100

Temperature control circuits

I made two small circuits today for temperature control of the extruder head on a reprap type 3D printer. The idea is to control the temperature, which needs to be somewhere between 200 and 240 C I think, using EMC2 and two parallel port pins. The first circuit is based on the 555 and produces [...]

PCB Milling

We have a 1994 LPKF Protomat S91 PCB mill in the lab for making prototype PCBs. Here it was used to cut a circular part (not a PCB) which was first drawn in CorelDraw, then saved in HPGL format, and then opened in BoardMaster which is the program that controls the mill through a quirky [...]

Monster torque servos

Gone is the HiTec light-blue box, and replaced with a clear one. These servos, which HiTec calls "monster torque" are designed for either 6.0V or a LiPo pack at 7.4V. They are about 10% bigger than the standard 20x40 mm footprint, and produce 36 kg*cm (6.0V) or 44 kg*cm (7.4V) of torque. To be tried [...]

Digikey FAIL

Tried to order some CUI encoders (102-1307-ND pic) and cables from digikey, but got these IC sockets instead... FAIL.

Heater fix: SSR replaced

The heating elements on this heater just kept on heating and heating independent of the temperature. I first checked the thermocouple that measures temperature - but that seemed OK, so the next thing I suspected was the solid-state relay that turns on/off the heating. Turns out this initial guess was right, and I was lucky [...]