External Flash Memory File System

Question

I'm building a weather data collector and I want to be able to dump that weather data somewhere. I've considered the options, and since I'm going to be storing a fairly small amount of data (in the megabyte range) I don't want to use SD cards (also SD cards are expensive). I've heard of use of NAND flash memory chips (like the W25Q32), and I was hoping that I could possibly interact with them in a simple way (since most ways require writing to each individual address). Is there possibly a way to build a file system within one of these small flash memory chips and interact with them as simply as interacting with an SD card?

TLDR: I want to interact with a flash memory chip easily to store basic ASCII data

• Chris Stratton: While you can put a filesystem on an SPI flash, it's generally a bad idea, as many filesystem map poorly to the block-erase nature of NOR flash, and filesystem APIs don't well represent access carefully tuned to the needs of flash. If you do, use a fileystem optimized for flash. Probably better and simpler though to organize your writes as a linear journal of data.
• rpmerf: Could you set up a server with a simple web application, put a WiFi module on the Arduino, and have it store data in a database? Could use apache or IIS if your on windows. set it up to run PHP. Set up a MySQL database. Have a page that accepts GET variables of the data and insert it into the database. You could set up another page to access/search/analyze the data.
• Carrot M: @rpmerf I've done this before, but it consumes FAR too much power and I plan to put these small weather data collectors in places away from infrastructure.
• Mikael Patel: Why not use the raw device commands and write blocks? Does your sketch really need a file system, i.e. more than a few files?
• Mikael Patel: There are a few Arduino boards out there that have RTC, SPI Flash and RF-modules, and are real low power design. See for instance Anarduino anarduino.com/miniwireless, or Moteino lowpowerlab.com/guide/moteino.

Answer 1

This lib offers a means of reading and writing ASCII arrays to flash devices. This would be a simple solution for such a data logger requirements. It's ASCII orientated.

https://github.com/schinken/Flash

Answer 2

I don't think you need a file system: that is usually needed when you want to manage many files. Your weather data log sounds like a single file.

What you seem to need is to access EEPROM as a stream, exactly like you would for an open file. There are stream wrappers around some EEPROM libraries, e.g. this one for ESP. I suggest you check it out and see if you can adapt it to the EEPROM library you use.

Answer 3

There is a way to do this. Using a 2ドル adaptor from eBay, you can hook it up to a micro sd card. An sad card for 4ドル can store 128mb of data, which is plenty for you.

Arduino Storage Tutorial with weather

128mb Micro Sd card

• Chris Stratton: This does not answer the question which was asked. The poster already seems familiar with what you propose, and is seeking to do something else.