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Low speed AVR oscilloscope V2.00 (Is updated on 19 Mar 2011)

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>> The firmware was updated on 19 Mar 2011 <<

A few months ago a friend of mine -car mechanical at profession- told me that he had problem with some car sensors. He couldn't check, with a simple multimeter, if a sensor was working properly. I advised him to buy a LCD oscilloscope instead of a normal oscilloscope, because of its small size. The use of an oscilloscope is very helpful because you can see the waveform that is produced by a "healthy" in-circuit-sensor* and you can compare it with the waveform of a "suspect" in-circuit-sensor.
After that, he told me that this oscilloscope costs a "fortune" for him as he has a small car service shop. I offered to help him by designing and constructing a small, cheap and workable LCD oscilloscope for him.

*in-circuit-sensor is the sensor which is connected on a board (PCB) or it's connected somewhere in the car. It's not a disconnected sensor.

You can download the source code, hex, schematic diagram,PCB and picture of the circuit .
 
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Step 1: Selecting the components

As the circuit has to be constituted by a few and cheap components, I chose the DEM128064A graphical LCD based on KS0108 controller chip to display the measured signals. The ATmega32 microcontroller is chosen because it has a lot of IN/OUT pins and a 2kB RAM size. 1kB is needed from gLCD and some bytes of the rest 1kB are used in C source code as registers. Because my oscilloscope has to read both AC and DC currents and at the same time it should have a High input resistance, I chose to use an LM358 which is a dual operational amplifier. The rest components like LM7805 , capacitors and resistors are very common and I won't refer to them.

Step 2: Designing the schematic diagram

Picture of Designing the schematic diagram

After I had chosen the components, I had to draw the schematic diagram of this circuit. For this purpose I used the Splan 5 that is not freeware but it is a very cheap schematic diagram software.

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odip16 days ago

mr, seradis..i.am .. trouble when burn atmega 32.i.am .. ask for help .To give way detail..i.am burn atmega 32 .... using kazama avr programmer, aid needs. I appreciate you., This e-mail me ... odiprasuma@gmail.com...

ForhadurR2 months ago

Another similar interesting project: https://github.com/hassansin/atmega16-portable-oscilloscope

rahulb22 months ago

hi, i want the progame of atmega 32 base avr oscilloscope

hamrique made it!4 months ago

Finally I did it...
Its my FYP :)

IMG_20140811_155305.jpgIMG_20140811_155316.jpgIMG_20140811_155340.jpg
hamrique4 months ago
Steve257 months ago

Looks like a cool project and usefull aswell. But i got a couple questions. Is it possible to use a blue screen like this? And what is K1 called? And last question. To programm it you just need to add an 2x5 male connector and burn the hex with an ISP programmer?

Hope to get an respond!

serasidis (author)  Steve257 months ago
1) >> Is it possible to use a blue screen like this?
No. Uses different LCD controller and pins. Only the resolution is the same (128x64 pixels)

2) >> what is K1 called?
Oh! I left the description in Greek language. I re-uploaded the schematic diagram in English.
Well, on that pin is connected the probe. Probe is a tool like that one on the attached picture.

3) >>To program it you just need to add an 2x5 male connector and burn the hex with an ISP programmer?
If you want you can do that! I programmed the ATmega32 with my STK500 programmer that already has a 40-pin DIP size socket for adding ATmega32 and burn the firmware.

I hope I answered your questions.

Regards,
Vassilis Serasidis
Oscilloscope_Probe.jpg
Steve25 serasidis7 months ago

Thanks for the answer! So i need an LCD screen wich is controlled by an KS0108. So something like this? And what size connector did you use for the probe?

Hope to get an respond!

serasidis (author)  Steve257 months ago

>>So something like this?

That LCD seems ok.

>>what size connector did you use for the probe?

Oscilloscope probes (usually) have BNC connectors

http://en.wikipedia.org/wiki/BNC_connector

mass13517 months ago

hi , more power, i made this project by ver1. programming carefully but the avr speed is very low! you now 5 khz is very down frec. for electronic devices . is ver.2 speed more than ver1. program?

thanks for you..

serasidis (author)  mass13517 months ago

Version 2 gives the voltage and frequency indication of the measured signal. Moreover I did a little bit improvement to the source code and the max measured signal increased from 5kHz to 7.5 kHz.

It's not big deal that because the internal Analog to Digital Converter (ADC) of ATmega32 is limited to 15 kilo samples per second, that reads max 7.5 kHz square waves. If you want to read triangular pulses then the maximum kHz of the measured signal is much lower.

MADeye1910 months ago

I have been trying to build the program(given on your website

as 'source code for V2')using AVR STUDIO 4.But when I 'Build and Run'

it in STUDIO,I recieve multiple errors like 'glcd.c:-No such file or

directory'

In AVR studio,I have also included the source file and header

file included in the source code.

I am a begineer in using AVR studio,so plz forgive my ignorance.

ALSO,will the circuit work directly if the ATMEGA32 is burned

with the given hex file as per the instructions on the site ?

mtaufiq42 years ago
I implement this but my lcd does not show any measurement....tell me whats the problem behind this so I will reduce this problem.....waiting for your replies...
nehanikita3 years ago
this display is not available at my place...so any other option for this?
Look at adafruit.com that is where I bought mine you can get it with a blue background with white text or black background and white text
I know most of the parts are common but it is hard to read what they are from the schamatic may I have the parts list? I have the micro controller, screen and the amplifer but I am having a hard time reading the values of the other compoients.
My total price is just under $42 I have some parts still in the mail but I will post a photo of it once I have it together and working
I have a list of most of the parts but I don't know what the vale of D1. I did a searchfor 8V2(that is what it says on the schematic) and could not find it on jameco.
serasidis (author)  WakeUpWolfgang3 years ago
The diode D1 is a zener diode at 8.2 Volts.
Thanks I have found the parts at jameco.com but the screen I found the screen at adafruit.com and my total price is around $45 -50 USD if you buy all new parts and 30 of it is the screen
CBX3 years ago
have you considered using an external ADC?

Will it work at 8mhz?
serasidis (author)  CBX3 years ago
>>have you considered using an external ADC?
That would be a good idea but there is not free time for that!

>>Will it work at 8mhz?
Yes, but you must change the crystal frequency in the source code and re-compile it. The circuit will run in low performance.
hATEmATH3 years ago
great! i'd like to make one also.
mtnkh3 years ago
hi
thanks for your perfect site.
I need some explanation for the structure of the c file of this project.could you help me please?
if you mail me that i will be pleased.
this is my email address:matin_lili@yahoo.com
serasidis (author) 3 years ago
The firmware has been updated to version 2.00

- Now, indications such as voltage and frequency are displayed on LCD.
- A small increment of sampling rate has been made too.
rolocz4 years ago
Hello, nice project. Some time ago I (re) built and XY oscilloscope that uses external ADCs. That makes it a lot faster and a lot of nice curves can be displayed. Not as well finished or as useful as yours, but still fun to build and try. If you please you can check it in my website: http://eercz.com/en/avr_xy_oscilloscope_nokia_lcd

Regards
qz90904 years ago
Would you recommend a inexpensive 1:10 probe that I can used with this scope? Maybe a supplier and part number? Thanks.
com4both4 years ago
 very good project..i have seen pc based oscilloscope...
but this one is very good.....

where can i get the lcd....its not available here at my place...
i can make online shopping..
can anybody  who made this project, send me few links for online shopping

what will be the cost of the LCD?

what is ks0108...do i need to buy this controller or simply lcd?

make my doubt clear....
dan_dan5 years ago
how much did the lcd display cost, nice design tho.
matchett8085 years ago
hey....what was your total cost? Very nice job though...am needing a oscilloscope so wondering if this is the cheapest way to skin this particular cat.lol
The Pololu AVR programmer has a built in SLO-scope that I really like. It only works from 0-5v, and only on windows, however. But its only $20(USD), so its great for simple low voltage applications.
serasidis (author)  matchett8085 years ago
The all project (including the probe) cost me about 70 euro.
I did the whole project in ~20-30 euro (<100 PLN)
nice one....good build and quite cheep.....compared to the commercial ones i have sourced.
jamilm95 years ago
if you don't want to make this get this $50 prebuilt o-scope.
http://www.seeedstudio.com/depot/digital-storage-oscilloscope-with-panels-p-167.html
there is also a kit but it needs smd soldering.
senfield5 years ago
hello serasidis, we can use the mega32l instead mega32, the code is the same? , about the xtal, change the frequency or something? (cause the max clock of the mega32 (16mhz) , i have a mega32l-8pi (8mhz) max, thanks
withume5 years ago
hlp, me to display the voltage,and frequency in the display........what changes hv 2 be done with this.
pkumarhu5 years ago
hi my name is pramod i hve done tis project it is very nice but i like to do some modifications i like to display the voltage and frequency on the lcd screen so pls help me in changing the code
adie_hendri5 years ago
hi to ALL heloo Mr serasidis mr serasidis giveme advise u havent my question
mog1235 years ago
Hey, I finished my oscilloscope!

http://i39.tinypic.com/30vk45l.jpg

It turns out i didn't need to use an inverter, your screen is the same as mine!
Although I have a problem: I'm using software 1.01 and I can't use the time/div buttons (left and right). Do you know a solution?
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