EPE resistivity logger

[Prospekteur]

You are totally right;-)

I love the internet for making it such easy for us to get informations (even if the internet has also its dark side). Back in the days you have to go in a library and often dont find the right books with the correct informations you need. Cant understand how people nowadays are not able to learn by themselves, because its such easy nowadays;-).

[ivconic]

It was never easier and cheaper to learn, study and educate yourself.
These are best times for educating.
But better the conditions; fewer of those are really ready to invest even slightest effort.
Almost everybody wants "all" and "now" and not to invest a thing from their side.
Back in 1999. probably 2000. i had dial up "internet" very slow and very limited.
It took me several hours of "buzzing" from modem to download one simple patent in pdf.
So i spent nights, weeks and months to collect few valuable documents from which i could learn something.
Later i heard of Geotech forum. I was not registered for couple of years, yet allowed to read topics and download schematics.
I registered in 2006. to be able to do more things and to join "dispute"!

Not only that i learned few grains of MD knowledge, also i improved my English to the comfortable usable level.
Not to talk like "Me Tarzan, you Cheeta... or you Jane???"
But to be able to put up together something that majority can understand.
Thanks to Geotech, of course, on the first place.
But also thanks to inner motivation and strong enthusiasm.
Seems younger generations are lacking both; motivation and enthusiasm.
And always rushing and in hurry. With no real reason for that.

[Omerta 1312]

Good evening, I made the earth resistivity logger but when I open it it shows a bar on the left and a 0 on the right.What's wrong?

[Omerta 1312]

Good evening, I made the earth resistivity logger but when I open it it shows a bar on the left and a 0 on the right.What's wrong?

[taxma1981]

Hi
Where can i find the software for the epe resistivity logger?

[Omerta 1312]

Download the Snuffler, you just have to make some changes to the circuit. There are old messages that say what you should do.Does anyone know how we change color and design in Snuffler?

[ivconic]

In the same spirit as i did with magnetometer; i am making preparations to modernize also EPE resistivity meter / logger.
Yesterday i draw this "sketchy" schematic, sort of proposal, how it may be done.
Lot of details to take into considerations yet.
One step at the time.
This is just first step.
[ATTACH]51154[/ATTACH]

I made "development system" for this.
Now i am writing code for it.
In meantime i noticed certain issue related to power supply.
The whole setup from the attached photo bellow is draining 170mA !!!
This is not acceptable.
Than i take it a part and measured current drain separately.
Resmeter board draws 47mA which is acceptable.
Later when i add SD card module and BT module; power drain will rise to 60-70mA, which is planned and acceptable frame.
But Arduino UNO board + I2C + LCD draws 120 mA !??
While I2C + LCD draws 55mA???
Overall this presents too much load and i had to stop and analyze the problem.
In final design it will not be Arduino included but only Atmega328P.
Also at present i had only one old obsolete and HUGE 16x2 LCD, which draws too much current.
So i had to order newer and smaller (standard) 16x2 LCD. Still waiting to arrive.
So... this will add certain delay in my work.
And i will probably have to redesign the power supply stage.
I will also check other UNO's that i have here on their power drain.
In meantime i do write some parts of code which can be accurately done without development board.
Also i am analyzing the "tactics" on handling and operating the future device.

[ivconic]

Also i have not decided on matrix size (later a file on SD) defined and stored in memory, later filled with logged data.
Obviously Atmega's memory is too small for keeping so much data.
In old design eeprom is used.
In my design i will use SD card as storage. Unlimited space.
Trade off would be the speed of indexing, listing and finding certain data, if needed by operater.
Yet i wonder about most productive and least trade offs choice on this.
By now i will use 99x99 matrix (99 columns and 99 rows).
Is it not enough or is it overkill?
I could use help on this by professionals...
Or i could still use some high capacity eeprom?
For much faster indexing and search through the data.
Generally i don't like eeproms.

[ivconic]

... or to give up completely from indexing, searching and reading the data from matrix by the Atmega itself and let that job to be done by Windows and Android software?
I guess this is best choice.

[ivconic]

Standard 16x2 LCD arrived.
I hooked up I2C on it.
24mA overall with full backlight On.
Comparing to previous 55mA.
Now i am getting somewhere...

[Omerta 1312]

Hello ivconic, in the resistance meter when I do research in which mode should I have it? A-B or H-L? Also in which of the two should I store?

[ivconic]

Hello ivconic, in the resistance meter when I do research in which mode should I have it? A-B or H-L? Also in which of the two should I store?

Irrelevant.
A-B mode is just test mode, displaying values at preamp. Later not used in further processing. Sort of "working values" for experienced operators.
H and L are values "Highest" and "Lowest" in one sampling sequence.
So you can work and record in either of modes. As you like. Not important.

[ivconic]

[ivconic]

Without much of brainstorming i included these working frequencies:
50Hz
40,80,85,90,137,140,
60Hz
42,48,87,96,102,108,147,165,168, 171

[Omerta 1312]

Thanks.The epe works fine but what season is better to do research with electrical resistance? After rain? When it has a lot of humidity or a little?