Hi All,
I am looking to build a data logger for Geophysics instruments such as Resistivity loggers and Gradient Magnetometers. This needs to log analog voltages via an analog input. I am an Electronics Engineer but not a programmer! I have done a few Windows bits in Visual Basic, but never any micro code.
I want to make this an Open Source project, as I believe this is the best way forward.
For anyone who is interested I can forward a specification of what I am trying to achieve.
I will use an ArduinoMega, with an LCD display, and an SD card shield.
I have found a few scattered posts mentioning similar projects but this is really something new. I know that Sir Morris will probably be able to help as I have read a lot of his excellent posts about SD cards etc.
Anyone able to help get the ball rolling? I can probably "hack" code a bit to mod it to what I need but am NOT a programmer!!
Can anyone help?
Cheers All
Well, can I assume you have designed the hardware, have a schematic or is this just at the specifications stage?
It might get the ball rolling if you define/provide which LCD you will use and how it is attached, the SD interface, what precision you need for A/D levels. How do the attached sensors work? (Might require external A/D)... etc.
How far into the hardware design phase are you?
Hi There,
Thanks for the reply. The first instrument the logger will need to be used with is a Differential Magnetometer. The electronics of this are a kit with a commercially made PCB. The requirement is to log a DC voltage between 0 and 2.5v. The internal analog input of an Arduino should do ok?
Logging would be triggered by the operator pushing a button to take the reading. There would also be an option to take one reading every second for use when walking across large areas (the operator walks at a constant speed around one M/s).
The next requirement is to log the data in a certain format to identify which grid square of a survey it belongs to for use with geophysics software. This is done in XYZ format. This looks something like this space delineated data below
0 1 1.25
Where the first two numbers are the grid coordinates and the last is the voltage value. A button would be needed to advance each line of the survey grid, and another to start a new grid.
I have written a full specification for this logger and can send it to you if you like.
Look forward to getting this going!
Bob
Hi,
Sorry forgot to mention about the LCD. No I have not chosen one yet, any basic 2 line display that is easily available will do.
Regarding the correct Arduino to use it may be that the mega is overkill what would your thoughts be??
Bob
Hi All,
There is a PDF file here detailing what this logger needs to do.
http://www.subgroundimaging.co.uk/logger/logger_spec.pdf
Does anyone have any suggestions which arduino would be best?
Would I need the mega or would the Duemilanove 328 be ok?
Cheers for now
Bob
This is similiar to what I'm doing on my project. I am sampling an analog voltage from a load cell in the 0-5 volts range at 240 times a second for anywhere from a quarter of a second up to 15 seconds and then storing each test on an sd card to but dumped later to a pc so the data can be graphed.
I have a 16 character by 2 line serial lcd module that I am using and will be building a menu interface for the user to interact with to change variables before the test. The user will navigate the menu, change settings, and start/stop tests via some push buttons bellow the LCD module.
I'm using a micro sd module from www.libelium.com to store my tests on.
The duemilanove didn't have the memory capacity to handle my requirements so I added on some external memory to do the job. With the requirements you posted in the pdf I think you should be fine with the duemilanove.
I'm at the point now where I have tested all the individual components with the arduino and now need to tie them all together and build the readouts and menu system.
The funny thing is I'm the opposite of you, I'm a software developer by profession but not a Electronics Engineer so the development part comes natural but the electronics is a bit harder for me to get some times. I'll offer as much help as I can in the development arena and maybe the next time I get stumped on the electronics you could help me understand it.
The way I attacked my project was to buy the components and then figure out how to interface each one of the components to the arduino individually. That way when you go to tie it all together you have a good understanding of how each component works with the arduino.
Hope that helps.
Thanks
John
The way I attacked my project was to buy the components and then figure out how to interface each one of the components to the arduino individually. That way when you go to tie it all together you have a good understanding of how each component works with the arduino.
This is what I do... but it's really the ONLY way to work on a project that involves many items you have not worked with before.
I'm hoping the newcomers take this lesson into account when working their own projects.
Agreed. The only glitch is that I did an accounting yesterday of how much I have spent on Arduino and related components, boards, etc. Yikes! :o
But I guess someone has to help turn this economy around by buying things. I just didn't realize just how much I was helping. ;D
yeah, seems like prototyping always costs more. 
I prototype with an Arduino KIT I assembled that is available from LADYADA.
http://www.adafruit.com/index.php?main_page=product_info&cPath=19&products_id=92
I supplied my own parts... and soldering the USB-Serial FTDI chip is easier than it looks at first.
I also burn the bootloader myself. It's all good practice (you know... for learning how to make stuff) and helps save a few bucks. I get satisfaction out of building stuff... not just writing code to make it work.