beginner - rtc, sd card, led digit display

Forum 2005-2010 (read only) Hardware Interfacing
1

Hello every1,
This is my 1st contact with such things for ages, so please excuse any really basic or stupid questions.

I plan to make a system that needs battery backed RTC, data logging and led digit display. (and lots of digital and analog io of course)
Searching around i ended up ordering this board:
http://www.seeedstudio.com/blog/?page_id=110
this sd card adapter:

and this rtc:

I am not even sure if they will work together, but i had to make a start.

I am also thinking of adding this:

can it work ok with the rest?

Am I on a wrong direction?

I am not familiar with the serial writing that i will probably need for data logging (i will not need a filesystem). will this setup allow me to keep writing, without overwriting anything, through unplanned restarts? I guess this means i need to save an address after each write and be able to skip to that if i am just after a restart (where should this be saved?). What I need to do is to keep logging for months until the data is sent to a pc, (or preferably just by removing the card and reading it on a pc)

I also need the program to have about 30 user defined variables that can be redefined any time. where should i start looking about it? and mainly, where should this data be stored? one fact is that in order to avoid hardware, there will be no configuration pad on the device, and everything will be set via usb from a pc application.

oops... this text got too long already, i'll pause here for now, waiting for any help, directions and suggestions.

  • Chris
2

Hey Chris-

I thought I'd tell you how pleased I was with my Gravitech LED display - they ship fast and the display seems great - they even have an Arduino example on their site. I built a quick little program using I2C and I couldn't even spell I2C before I got my display.

When I placed my order, I also needed an SD/MMC card adapter as well as an RTC, but Gravitech was more expensive than an unnamed "ELECTRONIC COMPONENTS Superstore" so I bought them elsewhere.

Two weeks later I'm still waiting, so I think that next time I'll take a closer look at Gravitech.

I don't see why what you've got wouldn't work together just fine - it looks close to what I'm building into my project.

I'd also suggest storing your user configuration information in the Arduino's EEPROM, it's got 1000 bytes (which should be more than enough for your application).

Sorry I can't give you more help.

I'd be interested in what others suggest about how to modify your configuration data; the only thing that comes to mind for me is make sure you leave the hardware serial port free and use it to pass data from the PC.

Brad.