Home Product Articles 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!


avatar zwaaier
Great idea Gabriel.
A shame it did not win the contest, but finishng the project will be the ultimate victory !

I do have a questionmark also: "Calculator, able to do math on real-time data", I am not sure what to imagine here ....., could it mean that when you are measuring a value from the scope a calculation with that value gets updated in real time while the graph on the scope changes ?
avatar ganzziani
Yes, I was thinking that you could have a math equation that uses a variable which feeds from an analog input. A simple example would be using a thermocouple, you could write an equation to convert the analog input value to the correct temperature in Celsius. This will allow you to monitor the temperature in Celsius in real time.
avatar Imedia
I agree that COMA is a great idea. I am very interested in the potential to interface all measurements to a PC via USB. To me this is even of greater importance than the LCD display. This allows for post processing on PC. Storing of data, etc. I would like to discuss this and explore possibilities.
avatar boseji
Best of luck for your STM32 Entry.
I wished that your design could have been part of PIC32 tops.

Warm Regards,
avatar mpechner
one word:
avatar ganzziani
Interesting idea. I will give it some thought in the next few weeks.
avatar Danial
Gabriel, put please for the drawing of the PCB COMA.
avatar Danial
By the way, RS-232 can be removed as unnecessary; board should be designed to combine all the blocks on a single board.
The microcontroller is used in the form of KIT EVAL PIC32 STARTER. To simplify the manufacturing of the device (to reduce the number of boards and to make a compact design), please convert the scheme so that no additional boards (kits) to use.
avatar nighty
Many ideas in no particular order :)

It would be so great if you could integrate this on the Natami ( http://www.natami.net) or propose this as an expansion board or link thru USB which would make it ideal so it could be connected to any OS / Machine out there that has a USB :)

remote control of the application from the PC and real time data flow would be nice too :) then you could also have the advantage of a bigger screen real estate.

Also why not use the Freescale K53 Kinetis ( you should look at the Analog part of this baby , albeit no FPU)
avatar Imedia
I also am very interested in this device. We develop educational material and have been seeking a USB controlled DVM and scope for use in educational kits for distance students. This type of device if controlled over USB and receiving data will allow students to conduct experiments and share results with other students and instructors. I would be very interested in pricing and quantity discounts. I would love to discuss the potential with you Please contact me below.

Grant Plowman
Program Director
Interactive Media Publishing
avatar truvahorse
Great handy tool for fast results. Thanks.

Mustafa YUKSEL
Please login to post comments or replies.




Shopping Cart

Your Cart is currently empty.

Featured Products

XMEGA Xprotolab
XMEGA Xprotolab


You should get a Nobel Prize for the Xprotolab.  Way cool.  So happy I chose this scope.

Chuck Linskens
CRL Engineering

Official PayPal Seal