Arduino Nano+LCD+Keypad+externalADC+external EEPROM or SDCard

Well, the topic is already saying it - I am planning to put all of this together with the least effort possible. I'm not sure if I'm having the best approach. I am planning to control LCD and keypad via hardware i2c and an Attiny controller, the external EEPROM over another (software)i2c and the ADC (LTC1867) over SPI.

The whole project is planned to be used for measuring and logging sensor data. A 16bit ADC is a must, and so is storing a large amount of data.

I'm pretty sure that's not the best way, I'd be glad if someone could point out a better solution.

Thanks.

The whole project is planned to be used for measuring and logging sensor data. A 16bit ADC is a must, and so is storing a large amount of data.

What kind of sensor data? How much data?

Given the size of the LCD, the keypad, and the SD card, if you go that route (and I think you probably will), I'm not sure why you want to go with the tiny, breadboard friendly nano, instead of something you can attach a shield to, but you didn't ask about that.

What kind of sensor data? How much data?

Sensor measuring data, analog, 0-5V. Logging time should be variable. I do have the software part for evaluation ready, it just needs to be rewritten (modified) a little for arduino. Storing capacity should be as high as possible, 1024kBit EEPROM is the least. I know an SD-Card would be better, but at the moment I don't see a way to control both ADC and SD with Arduino-SPI.

Given the size of the LCD, the keypad, and the SD card, if you go that route (and I think you probably will), I'm not sure why you want to go with the tiny, breadboard friendly nano, instead of something you can attach a shield to, but you didn't ask about that.

Because I already have a housing with LCD and keypad and I need something that fits in there when it's done. A shield would probably be too large.

Sensor measuring data, analog, 0-5V.

Oh, well that certainly clears things up.

Logging time should be variable.

Then you'll need a variable sized card.

Because I already have a housing with LCD and keypad and I need something that fits in there when it's done. A shield would probably be too large.

How are you going to fit the SD card in?

Seems like your project is a bit backwards. Typically, one creates a functioning system, then designs an enclosure for it. But, if you want to do it backwards, that's fine.