Open source and open hardware electronics project to build a low-cost digital oscilloscope with an 8-bit microcontroller and a mobile phone screen.


  • 4 input channels
  • no fixed frequencies; the ADC can be run with different clock cycles and then the time for one x-division is displayed in the display; the "td" value (in the images below, 47 microseconds and 9 milliseconds)
  • the display also shows a frequency estimate of the signal. The algorithm looks at the time between to successive crossings of the x-axis and calculates a frequency from that. For sine waves, this is reasonably accurate. In the right picture below I measure background noise with a frequency of 49 Hz; the left picture shows a 43 kHz oscillation.


OpenOsci in action

one channel four channels


Prototype schematic Prototype board

Please be aware that I built only one version. There are many flaws in that one version, but all photos/videos shown here are made with this version.

While playing around with this prototype, I was already making improvements to layout and board which I never built or tested.



  • (broken): Graphical Display routines for the Nokia 6100.
  • (broken): Port of the above routines to Siemens S65 screens.
  • thread about the screen


This is an old project of mine. It was done in 2006 and some parts might be out of date. I cannot guaranty proper functionality or fitness for any particular use.