A bug was discovered in the SD card reading function.The command $F,$F=<filename> failed.

[chenglianshu]

Hello, when using the grblHAL ESP32 firmware, the files can be read normally when using the $F command to read files from the SD card, but it still prints error:62. Furthermore, using the $F= command results in error:84. However, when I change the command to $F=/filename, it works correctly. My controller is an MKS DLC32 2.0. Whether I build the firmware using a web page or download the code and compile it myself, the result is the same. Below are screenshots of my tests. I'm unsure if these are the problem or a problem with my operation.

[terjeio]

$F=<20260319.nc> should return error:84 (Could not open file) since it is not a valid file name
$F=20260319.nc or $F=\20260319.nc are both valid, error:20 is returned since the file contains unsupported gcode.
However "errerror:20" is not the correct output on errors raised when streaming from SD card, I'll look into that.
I cannot replicate error:62 on $F, are you running the latest version? I recently made some changes to skip system/hidden directories that may be present on the card - these caused issues for another user.

[terjeio]

However "errerror:20" is not the correct output on errors raised when streaming from SD card, I'll look into that.

This is due to a bug in the ESP32 serial driver code, will fix in the next commit.

[chenglianshu]

$F=<20260319.nc> should return error:84 (Could not open file) since it is not a valid file name $F=20260319.nc or $F=\20260319.nc are both valid, error:20 is returned since the file contains unsupported gcode. However "errerror:20" is not the correct output on errors raised when streaming from SD card, I'll look into that. I cannot replicate error:62 on $F, are you running the latest version? I recently made some changes to skip system/hidden directories that may be present on the card - these caused issues for another user.

Thank you for your reply. This errerror:20 error didn't appear when I first started using the firmware, but it reappeared after I re-flashed the firmware. I also noticed that sometimes error:62 appears with $F, and it disappears after re-flashing the firmware, but then reappears. I'm wondering if it's a problem with my SD card format; my SD card is formatted as FAT32.

[terjeio]

The ESP32 is known to be a bit picky about which SD cards it works with, if you have more than one can you try a different? Preferably a different brand and not too large capacity (<= 16GB).
You may also try to dump the file to the console, best would be via a terminal program such as PuTTY: $F<=\20260319.nc
Is the output corrupted?

[chenglianshu]

The ESP32 is known to be a bit picky about which SD cards it works with, if you have more than one can you try a different? Preferably a different brand and not too large capacity (<= 16GB). You may also try to dump the file to the console, best would be via a terminal program such as PuTTY: $F<=\20260319.nc Is the output corrupted?

I've tried using $F<=20260319.nc, which outputs the file content. However, listing all files on the SD card sometimes results in error 62. This error is quite random, but fortunately, it doesn't affect the functionality.