SCANALOGIC
ikalogic's
easy to build high performance logic analyzer
By Ibrahim
Kamal
Last update:
14/9/11
Here is one project we are really proud of,
and we hope that its simple design will encourage you to build
your own, and use the provided software to obtain your own
logic analyzer for less than 10$.
This device can help you in most of your projects, it's an
essential measuring device when it comes to digital electronics.
Those pages will discuss all what you need to know to understand
how it works, and build your own, and use it. |
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 1.What
is a Logic Analyzer?
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You could read the definition
on wikipedia,
but as you may already know, I have my way of explaining things
to beginner!
I would say that a logic analyzer is a device used to view the
voltage of "logic" electric signals that are usually
too fast to be measured by a voltmeter. A logic analyzer it not
exactly like an oscilloscope, as it cannot measure analog voltages.
Actually, it can only measure the logic state of a signal, see
if it's a 1 or a 0. '0' being Zero volts and '1' being 5V (for
classic TTL logic devices).
The main keypoint that makes a logic analyzer better than another
is the sampling rate, or the maximum number of samples that can
be recorded by second.
From a functional point of view, a logic analyzer records the
states of logic signals, usually after some 'triggering
condition' is met, then, recorded signals are displayed on
a screen for in depth analysis.
2.
Introducing Scanalogic
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Scanalogic is a simple,
yet effective logic analyzer specially designed to be easily built
by beginners, so that it can be used for debugging and analyzing
their projects.
It can be used at sampling rates as high as 4
Million Samples per second. It has only 4 channels,
but that is more than enough for most hobby projects,
further more, most communication buses nowadays have very
few transmission lines, ranging from 2 to 4, so decided
4 was more than enough.
Scanalogic is a combination of a hardware (figure 2.a)
and software application (figure 2.c). As you will see
later, the hardware is as simple as it can get: An ATMEGA16
micro controller and a NAND gate! The code to be loaded
in the micro controller is provided at the end of this
page. |
Figure 2.a |
The
hardware records the samples at the desired sampling rate,
then send them to the PC application via the UART port
of the microcontroller and the RS232 port of the PC. If
your PC doesn't have an RS232 port, as mine, you can still
use a USB-RS232 converter cable, as shown in figure 2b.
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Figure 2.b |
The
software is made with visual basic. A setup file is included
at the end of the page. It is compatible with windows
ME all the way up to XP (or maybe Vista, can someone confirm?).
The Scanalogic software controls the hardware (as you
can see, there are no buttons on the hardware) It allows
you to setup the triggering conditions, to start sampling,
to receive sampled signals, display them, analyze them,
and even store them for later analysis. |
Figure 2.c |
3.
Building the hardware
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There are no secrets held for the hardware, as
the real power of this logic analyzer comes from the innovating
source code, loaded inside the ATMEGA16 microcontroller.
As
you can see in figure 3.b, there are only a microcontroller,
and a NAND gates IC and all of it resides in an old CDROM
power supply box. The DB9 connector for serial communication
is firmly glued to the box with an epoxy resin. The whole
is powered from the RTS line of the RS232 connection (pin
number 4), so there is no need for external power supply
(but you may as well use any 5V power supply if |
Figure 3.a |
your serial port cannot deliver the required current).
As you can see in the schematic below, there are no level shifting
IC like the MAX232, but believe or not, most if not 100% of current
serial communication hardware is compatible with the approach
below, where the signals are simply 'inverted', but not shifted
to +/- 12V. (Originally, in the RS232 protocol, a logic 1 is represented
with -12v, and a logic 0 is represented by +12V).
Pin 4 of the DB9 connector is used to power the device, as it
rises to +12V (theoretically) when a communication is being carried
out. The Diode D3 makes sure no negative power supply is applied
to the device, and the 5.1V zener diode D4 prevent supply voltage
from rising above 5.1 volts. Using the handshaking signals as
a power supply is far from being my invention, it have been used
in a lot of devices like mice and old external keypads...
Figure 3.b |
The probes are directly connected to micro controller.
A better approach would be to add buffers to protect the micro
controller but, for simplification, I didn't include one.
The crystal oscillator X1 can be anything from 1Mhz to 16Mhz,
but remember that the clock frequency of the microcontroller directly
affects the maximum sampling rate, according to the following
equation:
Max_Sampling_rate
= Clock_frequency/4 |
That is simply because, the most efficient code I could ever write,
needs at least 4 clock cycles to sample and store new signals.
D1 is simply a red LED, used to signal if the device is powered
up and correctly functioning.
Download
the hex file to be loaded into the ATMEGA16 for different
crystal frequencies:
-
8 MHz
- 12
MHz
- 16
MHz
(Need hex files for other frequencies? request
for it in the forum) |
4.
Downloading and using the PC side software
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Scanalogic
software, especially this first version is very simple and intuitive.
After you have plugged the Hardware, the configuration is simply
made via 3 steps:
1- Press F2 to chose the crystal frequency at which your microcontroller
is running, and to chose the COM port to which the hardware is
connected.
2- Press F3 to chose the sampling rate
3- Press F4 to chose the triggering condition
Then you simply need to Press F5 anytime to start the sampling.
Note that if you chose a triggering condition, the sampling will
only start when this condition is met.
Download
the installation file for SCANALOGIC
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I hope this article was useful. Any comments and further questions
are welcome in the forum below.
Project
under construction,
register to the forum to get informed of updates by e-mail.
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Preview of the last 15
messages discussing this page. Messages are sorted from the newest to
the oldest. |
Posted
by:
suhlig
on:
13 Jan 2012 |
Re: Scanalogic |
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I'am looking for a up to date hex file for atmega32. I found one, but the trigger do not working. If i set a trigger the application hangs. I think the hex is too old!? Can anybody help? THX
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Posted
by:
osgeld
on:
22 Dec 2011 |
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Re: Scanalogic |
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Is a repost of the VB source in the future, I would love to use this but no windows machine at the bench
Thanks!
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Posted
by:
dawn
on:
16 Nov 2011 |
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Re: Scanalogic |
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Tried to download zip file but the file is a registry mechanic program.
UPDATE: I was getting a Run time error 5. I have a PC with Windows 7 and have fixed the problem.
FIX
Steps.
1. Copy regsvr32.exc and paste in scanalogic folder.
2. In all programs-open accessories-right click on command prompt and run as administrator.
3. Open command prompt and change directory location to location of your scanalogic folder.
4. register the ocx files.
5. open scanalogic and it should work.
Had to download an ocx file. Have attached folder with the included file.
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Posted
by:
byteman
on:
14 Nov 2011 |
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Re: Scanalogic |
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I need monitoring slow signals. please upload hex file for 500KHz or 2MHz resonator.
Best regards.
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Posted
by:
jancz
on:
20 Oct 2011 |
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Re: Scanalogic |
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Hi,
after start of Scanalogic, program shoved message" Run Time error 13" Type mismatch. Next time the program cannot be setting, configurated etc.
Can You wite me, where is a mistake?
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Posted
by:
petros
on:
25 Sep 2011 |
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Re: Scanalogic |
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Hello .
Can you post again the visual basic source program because is corrupted.
Thank you 
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Posted
by:
sadmonew
on:
14 Sep 2011 |
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Re: Scanalogic |
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Quoting ikalogic: Here is file again.
Sorry guys a part of our database was damaged and there was some minor parts that couldn't be restored.. |
Thank you. The Scanlogic software work on PC without problem.
very nice. 
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Posted
by:
ikalogic
on:
12 Sep 2011 |
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Re: Scanalogic |
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Here is file again.
Sorry guys a part of our database was damaged and there was some minor parts that couldn't be restored..
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Posted
by:
slinul
on:
12 Sep 2011 |
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Posted
by:
sadmonew
on:
08 Sep 2011 |
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Re: Scanalogic |
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| Quoting pranavsharma2504: I guess Ive got it.... how do I upload it? give me your email address, I'll send it as an attachment |
hi.
you can send to my e-mail : sadmonew at gmail dot com
Thank you.
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Posted
by:
ikalogic
on:
08 Sep 2011 |
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Re: Scanalogic |
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| Quoting pranavsharma2504: I guess Ive got it.... how do I upload it? give me your email address, I'll send it as an attachment |
you can send it to contact at ikalogic doc com 
Thanks a lot in advance!
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Posted
by:
pranavsharma2504
on:
08 Sep 2011 |
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Re: Scanalogic |
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I guess Ive got it.... how do I upload it? give me your email address, I'll send it as an attachment
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Posted
by:
ikalogic
on:
08 Sep 2011 |
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Re: Scanalogic |
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Has any one got the scanalogic download file?
I am note sure where to find them on our new servers.. if someone who had downloaded it could post it that would be great! ortherwise, i'll try to debunk it from my old PC
sorry it have been a while since i stopped this project on my end..
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