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Video DVM

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This design awarded the third international prize in the Elektor Electronics 1997-98 Microprocessor and Microcontrollers Design Contest.

As seen on:
Elektor Electronics (english) issue 277
Elektor (german) issue 341
Elektuur (dutch) issue 427
Elektor (french) issue 251


    Video-DVM is a very cheap DVM that shows how an output as complex as a videocomposite signal can be generated entirely in software: two I/O pins and three resistors are all the hardware required. Connected to any TV set it displays voltages, included max and min peaks, using both giant digits and an analog bar-display . A serial data output for computer data logging is provided, too.

   The micro is the Atmel’s AT90S1200, ideally suited for hobbysts thanks to its 512 words flash memory, public programming protocols, free assembler and simulator available at www.atmel.com. More recently, other tools as free Basic and C compilers appeared on the Internet.


block schematic


   The circuit is not only a working project but also a guideline for any application using a tv set as giant display: all the hard work (interrupt driven, time balanced display software) is ready made, letting even novices to modify the code to build anything ranging:


Files available:

Download full description in Word format (DVM_DOC.ZIP, 28 kB),or, if you prefer, the same in Adobe Acrobat PDF format (DVM_DOC.PDF, 274 kB)
View or download full schematics (DVM_SCH.GIF, 45 kB)
Download full source code for the AT90S1200 (DVM_SRC.ZIP,  12 kB) ,  or only the
executables (DVM_HEX.ZIP, 2 kB)

Additional information:

Be sure to check the FAQ page for further information about the design issues.

Elektor Electonics magazine has published on the may 1999 issue a slightly modified circuit and pcb for the video-DVM. The article has been published in four languages (english, dutch, german, french). As the code is left unchanged, if you don't have the CD you can download it from here.

I have obtained permission from Elektor Electronics (Publishing) to duplicate these files for the purpose of publishing this Internet page. These files are available on a CD-ROM published by Elektor Electronics Publishing, P.O. Box 1414. Dorchester DT2 8YH, England, order number 986001-1, title uP-uC Hardware & Software 97-98.



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