Is flash memory on ATMega328 totally erased with new Sketch load?

Other Hardware Storage
1

Hi Sparkies,
I'm using the Uno as a data logger and looking to create two, 256 element arrays with data type float:
float sensorData[256];

Since I each float data type is 4 bytes, the space in SRAM used is: 4256(2)=2048 bytes, (I think), which maxes out the available space for any other variable storage.
If I was to save these arrays into Flash memory, could I access them periodically with a call function?
I don't want these arrays to occupy space once a new sketch is loaded. Will they be erased when i load up another sketch?

Thanks for your help,
Gunnar

2

You have 3 sorts of memory: flash (for programs), RAM (for variables) and EEPROM (for 'saved' variables).

The EEPROM on the Uno is only 1 Kb (1024 bytes). Under the default settings the EEPROM is preserved when you load new sketches. The RAM isn't.

You may possibly be better off investigating an SD card solution - there are various ways you can connect up a standard SD (or mini SD) card, that gives you a lot more storage.