Writing volatile buffers to the SD card error about sdfat-beta

[greiman]

I didn't see this post earlier. Did you solve the problem?

I ran your program with with the current release version of SdFat on a Teensy 4.1.

I modified the final part of the test like this:

   //read the vector back from the SD card
    if (written_size != file.read(buffer_read, written_size))
        Serial.println("Unsuccessful read of first block from SD card");

   for (uint16_t i = 0; i < buffer_size; i++) {
      if (buffer_read[i] != dma_adc_buff1[i]) {
        Serial.println("cmp error: " + String((uint16_t)i));
        break;
      }
    }
    if (buffer_read[1] == dma_adc_buff1[1]) {
        Serial.println("Looks like file was written to successfully");
    }
    else
   {
        Serial.println("Error in writing and then reading from file");
        Serial.println("Intended: " + String((uint16_t)dma_adc_buff1[1]));
        Serial.println("Read: " + String((uint16_t)buffer_read[1]));
        Serial.println("1st : " + String((uint16_t)buffer_read[0]));
    }
    file.close();

Here is the output:

Successful initalization of DMA Buffer 1
Looks like file was written to successfully