I'm having an issue where anytime I run a program such as the SD card read write example (Below) the COM port disconnects. The only changes I have made to the example code is I am using SPI1 instead of SPI0 so the pins changed.

When the COM disconnects it comes back about 20 seconds later with an error message in its properties window

"Windows has stopped this device because it has reported problems. (Code 43)

A request for the USB device descriptor failed."

Additionally I am suspicious of these lines through isolating them, if I remove all lines relating to SPI the code doesn't fail and I don't have the COM issue. (though the SD card obviously doesn't work)


Thanks! -Rian

  SD card read/write

  This example shows how to read and write data to and from an SD card file
  The circuit:
   SD card attached to SPI bus as follows:
   ** MISO - pin 4
   ** MOSI - pin 7
   ** CS   - pin 5
   ** SCK  - pin 6

  created   Nov 2010
  by David A. Mellis
  modified 9 Apr 2012
  by Tom Igoe

  This example code is in the public domain.


// This are GP pins for SPI0 on the Raspberry Pi Pico board, and connect
// to different *board* level pinouts.  Check the PCB while wiring.
// Only certain pins can be used by the SPI hardware, so if you change
// these be sure they are legal or the program will crash.
// See: https://datasheets.raspberrypi.com/picow/PicoW-A4-Pinout.pdf
const int _MISO = 16;
const int _MOSI = 15;
const int _CS = 17;
const int _SCK = 14;

#include <SPI.h>
#include <SD.h>

File myFile;

void setup() {
  // Open serial communications and wait for port to open:

  Serial.print("Initializing SD card...");

  // Ensure the SPI pinout the SD card is connected to is configured properly

  if (!SD.begin(_CS)) {
    Serial.println("initialization failed!");
  Serial.println("initialization done.");

  // open the file. note that only one file can be open at a time,
  // so you have to close this one before opening another.
  myFile = SD.open("test.txt", FILE_WRITE);

  // if the file opened okay, write to it:
  if (myFile) {
    Serial.print("Writing to test.txt...");
    myFile.println("testing 1, 2, 3.");
    // close the file:
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening test.txt");

  // re-open the file for reading:
  myFile = SD.open("test.txt");
  if (myFile) {

    // read from the file until there's nothing else in it:
    while (myFile.available()) {
    // close the file:
  } else {
    // if the file didn't open, print an error:
    Serial.println("error opening test.txt");

void loop() {
  // nothing happens after setup
  • 1
    There is a Raspberry Pi part of Stack Exchange, they may be able to help you better.
    – Nick Gammon
    Jul 21, 2023 at 1:29


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