Designing the COMA


Let your mind enter a state of deep unconsciousness, imagine that instrument you have always desired, an instrument capable of performing multiple tasks, data acquisition, signal generation, and much, much more. Imagine no more because this instrument is finally here. The COMA.

COMA+ The All in One Instrument

Update 2010/12/18:
The COMA is back in delevelopment, now, called the COMA+.

I am participating in the STM32 Design Challenge, I thought it was a good incentive to continue development of this project. I will improve the original specifications, like using a TFT display and using a few external ICs to simplify the design, like the ICL7135 multimeter IC, and a DDS to generate the waveforms, probably the AD9833.


+ More

Design files provided for reference only
HW Block Diagram sch_icon code-icon forums
Diagrams Schematics Code Forums

The COMA was my entry to Microchip's PIC32 contest. It was also an idea I had back in my academic years. I always wished of integrating an oscilloscope, a multimeter and a calculator in a single portable device. With the PIC32 contest I saw an opportunity for developing my project while getting a chance to win free prizes!

The initial features and specifications:

Main Features:

  • 2 Channel, 8bit 16MSPS Oscilloscope
  • FFT on acquired data
  • 8 Channel Logic Analyzer
  • Arbitrary Signal Generator
  • Frequency Generator
  • Multimeter:
  • Volt Meter, 1 M ohm Input impedance
Voltage Ranges Ammeter More Features
+/- 204.8V, 400mV sensitivity +/- 10.24A, 20mA sensitivity 0.2 ohm series Ohmmeter / continuity test
+/- 20.48V, 40mV sensitivity +/- 204.8mA , 400uA sensitivity 10 ohm series L/C Meter
+/- 2.56V, 5mV sensitivity +/- 2.048mA, 4uA sensitivity 10 ohm series Logic probe
+/- 256mV, 500uV sensitivity +/- 20.48mA, 40uA sensitivity 100 ohm series Frequency meter
  +/- 204.8uA, 0.4uA sensitivity 100 ohm series Transistor check
  • Calculator, able to do math on real-time data
  • Graphic LCD 128x128
  • SD Card for data storage
  • Optional connection to PC via USB or RS-232


  • 2 Analog Channels
  • Input Impedance: 1M ohm
  • Maximum Input Voltage: +/- 25V
  • A/D Converter Resolution: 8 bits
  • Maximum Sampling Rate: 16MS/s shared
The COMA was among the eight finalists, unfortunetely it didn't win. But the design of the COMA is still active.

Here are some images and videos of the COMA prototype:

Coma Block Diagram

COMA Prototype


Wish List:

  • Mini Spice Simulator
  • Engineering Notes
  • Mini Labview kind application
  • Games
  • MOD/MP3 Player

The COMA will be the ultimate engineering tool!