I'm going to try and use SPIFFS instead of storing big arrays in RAM. I'm concerned with heap usage, and speed.
1) If i open a file, I use about 120Bytes of heap, so not much. is this really the overhead of having a file open?
2) Is having more than one file open at a time acceptable (Seems to maintain the 120bytes of heap, even 120bytes for 3 files) as writing to an open file is super fast, whereas .. see below..
3) Is it acceptable to open a file, and keep it open? are writes immediately saved... because close() takes around 3-4ms.
just wanting to know more about how it all works?
many thanks all