Bill Greiman

> So the data has been written to the SD but it's not accessible because the FAT Region hasn't been updated. Is it possible to recover the data/update the directory...

Because of the structure of exFAT, raw writes to a preallocated file won't work on exFAT. The valid length field won't be set. If you try to rewrite an existing...

> The original data source is a CAN bus running at 500MB/s That's really amazing Gigabit Ethernet is only about 125 MB/s > A gigabit network can be incredibly fast....

Forget everything I told you if you are using shared SPI. Don't bother me if you have performance problems. You can forget using a fast logger if you share SPI....

People are making SdFat work with Giga. See the Arduino Giga [forum](https://forum.arduino.cc/t/configuring-spi-speed-for-use-in-sd-library-on-arduino-ghiga/1196101/15). I don't have a Giga and am too busy to try helping people. It should work on SPI,...

> Is there a solution by keeping the STM32duino 2.7.0 version ? Looks like `transfer(txBuf, rxBuf, count)` has been removed from SPI in 2.7.0. > Search "transfer" (9 hits in...

I will remove the custom STM32 code. For now use the standard Arduino API by editing SdFatConfig.h and change this. ` #define SPI_DRIVER_SELECT 1 // Can I quote you on...

You can do better by using this in SdFatConfig.h ``` #define SPI_DRIVER_SELECT 1 ... #define USE_SPI_ARRAY_TRANSFER 1 ``` STM32 Nucleo L476RG > write speed and latency > speed,max,min,avg > KB/Sec,usec,usec,usec...

Here is Teensy 4.1 using DMA SPI with: ``` #define SPI_DRIVER_SELECT 1 ... #define USE_SPI_ARRAY_TRANSFER 1 ``` > write speed and latency > speed,max,min,avg > KB/Sec,usec,usec,usec > 5175.98,1221,98,98 > 5186.72,110,98,98...

@fpistm Why should I waste time on STM32? Here is a logic analyzer trace of transfer(buf, count) 40 MHz clock. almost 600 ns dead time between bytes. ...