Added ssd1306 scan code

firmware/display_test_ssd1306/display_test_ssd1306.ino

@@ -0,0 +1,29 @@
+#include <Wire.h>
+
+void setup() {
+  Serial.begin(115200);
+  Wire.begin(23, 19); // SDA, SCL
+  Serial.println("\nI2C Scanner");
+}
+
+void loop() {
+  byte error, address;
+  int nDevices = 0;
+
+  for (address = 1; address < 127; address++) {
+    Wire.beginTransmission(address);
+    error = Wire.endTransmission();
+
+    if (error == 0) {
+      Serial.printf("I2C device found at 0x%02X\n", address);
+      nDevices++;
+    }
+  }
+
+  if (nDevices == 0)
+    Serial.println("No I2C devices found");
+  else
+    Serial.println("Scan done.");
+
+  delay(2000);
+}