Category: Everything

I have been hacked!

How could this happen? My website has been hacked in the beginning of this week! As a reaction my provider immediately took it offline, because a script on the server has been used to send out spam…

A bicycle trip: all municipalities in Uppsala county – on a day

Uppsala county and its eight municipalities (map borrowed from the cache description).

There is a geocaching challenge in Uppsala: to visit all 8 municipalities in the county of Uppsala within 24 hours. When I first saw this challenge, I wondered if it was possible to do this by bicycle. I took a map and roughly sketched what would be the shortest possible route to travel to all… Continue reading A bicycle trip: all municipalities in Uppsala county – on a day

The humble capacitor

I just watched some videos and got inspired… Are Your Capacitors Installed Backwards? Capacitors 1965 US Air Force Training Film

Yesterday at QuizClash

Beinahe unentschieden, dann aber doch noch gerade gewonnen - aber was will mein Gegner im Chat?

Sorry, this entry is only available in Deutsch.

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Categorized as Computers

ATmega328P – measuring its own supply voltage III

Timing of the internal analog-to-digital converter of an ATmega328P with a 5 V supply voltage.

After the first two parts of this series ATmega328P – measuring its own supply voltage ATmega328P – measuring its own supply voltage II where I investigated the possibility of the Atmel ATmega series microcontrollers to select the internal bandgap voltage VBG as input for the analog-to-digital converter. Using the analog supply voltage AVcc as reference… Continue reading ATmega328P – measuring its own supply voltage III

ATmega328P – measuring its own supply voltage II

A simple yet versatile testcircuit for the analod-to-digital converter.

Here is a brief follow up from yesterday’s post on the internal reference voltage VBG of the ATmega328P. I wrote a small test program where I wait for a variable delay time after switching the input multiplexer of the analog-to-digital converter to the internal bandgap reference voltage VBG. Using the AVcc of as the conversion… Continue reading ATmega328P – measuring its own supply voltage II

ATmega328P – measuring its own supply voltage

A sketch of the test circuit on a breadboard.

The trick is not new, it is utilized in the AVR transistor tester which you can buy for quite cheap money from China, and it has been discussed in internet forums for almost 10 years (see below for some links). The Atmel AVR microcontrollers feature an analog to digital converter (ADC) equipped with a multichannel… Continue reading ATmega328P – measuring its own supply voltage

XeTeX and your math is bitmapped?

Bitmapped math in XeLaTeX output.

I have now been using XeLaTex exclusively for quite a while for all my LaTeX work, which essentially means for everything: lecture notes, lecture slides, lab instructions, letters, reports,… For some shorter time the symbols in my equations would show up ok on screen but a bit blurry on printouts. I was looking for the… Continue reading XeTeX and your math is bitmapped?