OpenOsci

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

Capabilities

• 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.

Fotos

Hardware

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.

• Schematic: openosci_060306_produced.sch
• Board: openosci_060306_produced.brd

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

• Schematic: openosci_060426.sch
• Board: openosci_060426.brd

Software

• Download: source_code.zip
• code reference manual: pdf, html

Links

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

Disclaimer

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 It was done in 2006 and some parts might be out of date.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.