Reading from SD Card and Writing to Keyboard Simultaneously

Projects Programming
1

I have a long piece of text I would like my Arduino Micro to output using Keyboard HID. However, since the text is too long to be stored in the internal memory I have decided to use an SD Card. Opening the .txt file in the SD card, reading the characters one-by-one into a String str, and then calling Keyboard.println(str) sadly doesn't work because I cannot store the whole text file in a String variable, obviously.

When I try to do the Keyboard operations while reading from the file, the Keyboard does not output anything.

while (myFile.available()) {
    char letter = myFile.read();
    Keyboard.write(letter);
}

I am thinking the two libraries collide because they each use SPI, so I cannot simultaneously read characters from a file and output them as keystrokes. Any thoughts?

2

Are you setting/resetting the SPI setup correctly for each piece of hardware - the CPHA or CPOL
may differ, or the clock frequency may be different. In theory, for well behaved hardware, so long as
nether CS line is active you can change CPOL and get away with different SPI styles inter-working,
but its the sort of thing that may be thornier than you'd hope.