Category: English

  • Battery replacement for Kobo Libra H20

    Battery replacement for Kobo Libra H20

    A good friend of mine has a Kobo Libra e-reader that did not turn on or charge anymore. I repaired it. I expected a broken connection between battery and e-reader electronics, perhaps after a fall, or a defective USB connector (as that is used for charging), but it turned out the battery itself was defective.…

  • Neon Watch design-information

    Neon Watch design-information

    Specially for those desiring to build their own neon-indicator watch, or for those who just want to know how it’s made (Bunch a’ enginèèrds! 😉 ). In this blogpost I’ll share the design files. (Ook in het Nederlands beschikbaar) For those that rather watch the outside of the watch: here is a link to the…

  • Optical data-transmission

    Optical data-transmission

    In the post about the neon watch I mentioned the neon watch gets set to the correct time by a computer program that flashes the screen to send the time. Since that post I have modified my ‘lichtwekker’ (Light-up alarm clock / lineair clock) so that too can be used to set the neon watch.…

  • SMD on breadboard

    SMD on breadboard

    When soldered between pinheader pins, SMD components can be used on breadboard. With a bit of trouble they can even be labeled, but a reference picture or keeping them in labeled ziplock baggies is clearer. The components in the picture where used for breadboarding the neon watch.

  • Neon watch

    Neon watch

    Inspired by Nixie watches (like the original from cathode corner, or this other one), I thought it would be nice to make a watch with neon indicator lamps. This blogpost shows the result. (Ook in het Nederlands beschikbaar)

  • Give it time

    Give it time

    In hindsight, it’s obvious. Switching the ADC reference voltage takes a bit of time, the voltage on the AREF pin cannot change instantaneously. The Atmega48/88/168/328 datasheet recommends to discard the first sample after changing the reference voltage (in paragraph 24.5.2). So I did. But still I got false readings (or rather: my Atmega48A did). I’m…

  • Battery replacement for Kobo Glo

    Battery replacement for Kobo Glo

    My Kobo Glo sometimes suddenly restarts. I’ve had it for so long that I did not know for how long, but it turned out I bought it in 2013. So it, and its battery, is about 10 years old. The battery seemed still fine – okay runtime and voltage does not significantly sag under load…

  • tip: AVRdude on mac – using built-in from arduino

    tip: AVRdude on mac – using built-in from arduino

    More of a note to self*, since installing avrdude resulted in an avrdude without USB support. While Arduino also uses avrdude “under the hood”, but has USB support. And it would be nice if Arduino’ s avrdude can be used stand-alone, and it can: “/Applications/ -C/Applications/ -v -patmega328p -cusbasp -Pusb -e -Ulock:w:0x3F:m -Uefuse:w:0xFD:m -Uhfuse:w:0xDA:m -Ulfuse:w:0xFF:m…

  • Real Time Clock modification

    Real Time Clock modification

    I bought one of those Real Time Clock modules: I noticed it has a diode and resistor to charge the battery on the back. But I plan on using a non-rechargable CR2032 cell. So these had to be removed: I also removed the power LED, since I plan on using it in an alarm clock…