At this time code very dirty and contain a lot of debug and test info and i not add it to git (if need i can send code on mail), at this time it only of 'proof of concept'
SD card support need only ~8-9kB for FatFS vs long filenames (possible reduce size on 3kB if use old DOS format 8.3 names)
RTC need additional 1kB (most of code for convert/user input output)
Low level functions for init/read/write SD card need ~2kB
FatFS need ~1.5kB of RAM (possible reduce to ~800bytes)
512 bytes for file directory search read buffer
512 bytes for read/write buffers (FatFS allow use directory search buffer for this)
and about ~200 bytes for
At begin i try use another lib for filesystem support like PetitFS
It size only ~2kB and need 600byte of Ram (512 read/write buffer can removed, but it huge reduce read/write speed all data need read every time), but have very limited create/write file support
VinxFS - possible better, but i not test it
So at this time need only ~12kB flash and 1.5kB Ram (i think possible also add this to NanoVNA - H it have ~14kB free flash and possible free ~1kB ram from spi buffer or use it)
Possible not use filesystem and use direct sector read write, it huge reduce code size, but need add additional PC mode/soft for get data from it.
Also not added USB support for use NanoVNA as card reader (USB still in Serial mode)
Gyula Molnar search LCSC and I found some slot variants: XUNPU TF-115K and THD THD2528-11SD-GF
Need search
microSD? Memory Card "connector&Ejector"
option for easy insert and remove card (use Push In£¬Roll out option)
On Fri, May 22, 2020 at 04:10 PM, Larry Rothman wrote:
DiSlord,
This absolutely fantastic!? How much free flash is left over now for other
enhancements?
As for the card detect switch, can you use one of the spare pins on the uP as
a sense input from the card slot switch? That way, you can verify quickly if a
card is present.
Please add the code to your GitHub repo (if not there already) as I would like
to see how you implemented this.
Thanks!
Larry
