feat: add bench example

Fixes #80

Signed-off-by: Frederic Pillon <frederic.pillon@st.com>

Author: fpistm

examples/Bench/Bench.ino

@@ -0,0 +1,91 @@
+#include <STM32SD.h>
+
+#define TEST_FILE_NAME "/bench.txt"
+#define TEST_BLOCK_SIZE 4096  // Size of each data block in bytes
+#define TEST_BLOCK_COUNT 400  // Number of blocks to write and read
+
+File testFile;
+
+void setup() {
+  delay(2000);
+
+  Serial.begin(115200);
+  while (!Serial) {
+    delay(10);  // Wait for Serial to initialize
+  }
+
+  Serial.println("Initializing SD card...");
+  if (!SD.begin()) {
+    Serial.println("SD initialization failed!");
+    while (1)
+      ;
+  }
+  Serial.println("SD initialization successful.");
+  Serial.flush();
+
+  // Perform write speed test
+  if (writeSpeedTest()) {
+    // Perform read speed test
+    readSpeedTest();
+  }
+}
+
+bool writeSpeedTest() {
+  bool status = false;
+  Serial.println("Starting write speed test...");
+  Serial.flush();
+  // Prepare test data
+  uint8_t buffer[TEST_BLOCK_SIZE];
+  for (uint32_t i = 0; i < TEST_BLOCK_SIZE; i++) {
+    buffer[i] = i % 256;
+  }
+
+  // Open file for writing
+  testFile = SD.open(TEST_FILE_NAME, FILE_WRITE);
+  if (!testFile) {
+    Serial.println("Failed to open file for writing.");
+  } else {
+
+    unsigned long startTime = micros();
+    for (int i = 0; i < TEST_BLOCK_COUNT; i++) {
+      testFile.write(buffer, TEST_BLOCK_SIZE);
+    }
+    testFile.close();
+
+    float speed = (TEST_BLOCK_SIZE * TEST_BLOCK_COUNT) / ((micros() - startTime) / 1000000.0) / 1024.0;
+    Serial.print("Write speed: ");
+    Serial.print(speed, 2);  // Display speed with 2 decimal places
+    Serial.println(" KB/s");
+    Serial.flush();
+    status = true;
+  }
+  return status;
+}
+
+void readSpeedTest() {
+  Serial.println("Starting read speed test...");
+  Serial.flush();
+  // Open file for reading
+  testFile = SD.open(TEST_FILE_NAME, FILE_READ);
+  if (!testFile) {
+    Serial.println("Failed to open file for reading.");
+  } else {
+
+    uint8_t buffer[TEST_BLOCK_SIZE];
+    unsigned long startTime = micros();
+    for (int i = 0; i < TEST_BLOCK_COUNT; i++) {
+      testFile.read(buffer, TEST_BLOCK_SIZE);
+    }
+    testFile.close();
+
+    float speed = (TEST_BLOCK_SIZE * TEST_BLOCK_COUNT) / ((micros() - startTime) / 1000000.0) / 1024.0;
+    Serial.print("Read speed: ");
+    Serial.print(speed, 2);  // Display speed with 2 decimal places
+    Serial.println(" KB/s");
+    Serial.flush();
+  }
+}
+
+void loop() {
+  // Do nothing in loop
+}