Arduino MKR WiFi 1010 SPI Flash memory shield

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I have a couple of Arduino MKR WiFi 1010, and It’s potent, but I notice a tedious lack: there isn’t a Flash memory to store data. I have already written some articles on controlling external SPI Flash memory “How to use external SPI Flash memories”, but now I’d like to simplify the process, and I have created a simple PCB shield to add external SPI Flash memory in the fastest way.

Arduino MKR WiFi 1010 SPI Flash memory storage shield
Arduino MKR WiFi 1010 SPI Flash memory storage shield


Here the simple PCB shield PCBWay
PCB from PCBWay

The PCB is straightforward, and I added some jumper to soldering to select the CS pin.

Arduino MKR WiFi 1010 SPI Flash PCB shield
Arduino MKR WiFi 1010 SPI Flash PCB shield

The configuration is the same as the examples already posted.

Arduino MKR WiFi 1010 pinouts low resolution
Arduino MKR WiFi 1010 pinouts low resolution

Here the Arduino Amazon Arduino MKR WiFi 1010

Pay attention to the CS pin that is selectable on the PCB.

ArduinoSPI Flash
4/CS Pulled UP if not standard CS
10DI (IO1)
8DI (IO0)

From the up, you can see how the shield appears.

Arduino MKR WiFi 1010 SPI Flash memory shield
Arduino MKR WiFi 1010 SPI Flash memory shield

For my scope, I usually use a w25q64 chip that is 8Mb Flash, and It’s sufficient for all my scope.

Here my SPI Flash selection w25q16 SMD 2Mb - w25q16 Discrete 2Mb - w25q32 SMD 4Mb - w25q32 Discrete 4Mb - w25q64 SMD 8Mb - w25q64 Discrete 8Mb - w25q128 SMD 16Mb - w25q128 Discrete 16Mb W25Q32 W25Q64 w25q128 module 4Mb 8Mb 16Mb

Here the SMD buttons 3*6*2.5 SMD buttons 3X6X2.5

SMD 805 capacitory 0805 SMD Capacitor kit

The result Is very useful, and the space used Is limited.

Arduino MKR WiFi 1010 SPI Flash memory shield
Arduino MKR WiFi 1010 SPI Flash memory shield

Example Sketch

Here is a simple example.

 *  Use SPIFlash with FAT filesystem
 *  Write data inside a file
 *  Read data and info from the file
 *  Get the list of files in the directory
 *  library Adafruit_SPIFlash and SdFat - AdafruitFork
 *  by Mischianti Renzo <>
 *	SPIFlash connected via SPI standard check wiring on the article

#include "SdFat.h"
#include "Adafruit_SPIFlash.h"

Adafruit_FlashTransport_SPI flashTransport(SS, SPI); // Set CS and SPI interface
Adafruit_SPIFlash flash(&flashTransport);

// file system object from SdFat
FatFileSystem fatfs;

//The setup function is called once at startup of the sketch
void setup()
	  // Initialize serial port and wait for it to open before continuing.
	  while (!Serial) {
	  Serial.println("Adafruit SPI Flash FatFs Full Usage Example");

	  // Initialize flash library and check its chip ID.
	  if (!flash.begin()) {
	    Serial.println("Error, failed to initialize flash chip!");
	    while(1) yield();

	  Serial.print("JEDEC ID: "); Serial.println(flash.getJEDECID(), HEX);
	  Serial.print("Flash size: "); Serial.println(flash.size());

	  // First call begin to mount the filesystem.  Check that it returns true
	  // to make sure the filesystem was mounted.
	  if (!fatfs.begin(&flash)) {
	    Serial.println("Error, failed to mount newly formatted filesystem!");
	    Serial.println("Was the flash chip formatted with the SdFat_format example?");
	    while(1) yield();
	  Serial.println("Mounted filesystem!");

	  // create directory mischianti if not exist
	  if (!fatfs.exists("/mischianti")) {
	    Serial.println("mischianti directory not found, creating...");

	    // Use mkdir to create directory (note you should _not_ have a trailing slash).

	    if ( !fatfs.exists("/mischianti") ) {
	      Serial.println("Error, failed to create directory!");
	      while(1) yield();
	    }else {
	      Serial.println("Created directory!");

	  // Create a file
	  File writeFile ="/test.txt", FILE_WRITE);
	  if (writeFile) {
		  Serial.println("Opened file /test.txt for writing/appending...");

		  // Once open for writing you can print to the file as if you're printing
		  // to the serial terminal, the same functions are available.
		  writeFile.print("Write a number: "); writeFile.println(123, DEC);
		  writeFile.print("Write HEX number: 0x"); writeFile.println(123, HEX);

		  // Close the file when finished writing.
		  Serial.println("Wrote to file /test.txt!");
	  } else {
		  Serial.println("Error, failed to open test.txt for writing!");
		  while(1) yield();


	  // Now open the same file but for reading.
	  File readFile ="/test.txt", FILE_READ);
	  if (readFile) {
		  // Read a line of data:
		  String line = readFile.readStringUntil('\n');
		  Serial.print("First line of test.txt: "); Serial.println(line);

		  // You can get the current position, remaining data, and total size of the file:
		  Serial.print("Total size of test.txt (bytes): "); Serial.println(readFile.size(), DEC);
		  Serial.print("Current position in test.txt: "); Serial.println(readFile.position(), DEC);
		  Serial.print("Available data to read in test.txt: "); Serial.println(readFile.available(), DEC);

		  char filename[64];
		  readFile.getName(filename, sizeof(filename));
		  Serial.print("File name: "); Serial.println(filename);

		  Serial.print("Is file a directory? "); Serial.println(readFile.isDirectory() ? "Yes" : "No");
	  } else {
		  Serial.println("Error, failed to open test.txt for reading!");
		  while(1) yield();

	  // You can open a directory to list all the children (files and directories).
	  File testDir ="/");
	  if (testDir) {
		  if (!testDir.isDirectory()) {
			Serial.println("Error, expected test to be a directory!");
			while(1) yield();
		  Serial.println("Listing children of directory /:");
		  File child = testDir.openNextFile();
		  while (child) {
			Serial.print(child.size()); Serial.print("bytes \t");

			char filename[64];
			child.getName(filename, sizeof(filename));

			// Print the file name and mention if it's a directory.
			Serial.print("- "); Serial.print(filename);
			if (child.isDirectory()) {
			  Serial.print(" (directory)");
			// Keep calling openNextFile to get a new file.
			child = testDir.openNextFile();
		  Serial.println("All file in the directory writed");
	  } else {
			Serial.println("Error, failed to open test directory!");
			while(1) yield();


// The loop function is called in an endless loop
void loop()


And here is the Serial output.

Connetti alla porta seriale COM10 a 115200
Adafruit SPI Flash FatFs Full Usage Example
Flash size: 8388608
Mounted filesystem!

mischianti directory not found, creating...
Created directory!

Opened file /test.txt for writing/appending...
Wrote to file /test.txt!

First line of test.txt:

Total size of test.txt (bytes): 2845
Current position in test.txt: 20
Available data to read in test.txt: 2825
File name: test.txt
Is file a directory? No

Listing children of directory /:
2845bytes 	- test.txt
0bytes 	- mischianti (directory)

All file in the directory writed


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