Init fork from Stuart Robinson's repo

examples/Hardware_Checks/ESP32/30_I2C_Scanner/30_I2C_Scanner.ino

@@ -0,0 +1,72 @@
+// --------------------------------------
+// i2c_scanner
+// from: https://playground.arduino.cc/Main/I2cScanner/
+
+// This sketch tests the standard 7-bit addresses
+// Devices with higher bit address might not be seen properly.
+
+
+#include <Wire.h>
+uint16_t counter;
+
+#define SDA 21
+#define SCL 22
+
+void setup()
+{
+  Wire.begin(SDA, SCL);                              //format is Wire.begin(SDA,SCL);
+
+  Serial.begin(9600);
+  Serial.println(F("I2C Scanner starting"));
+  Serial.println();
+}
+
+
+void loop()
+{
+  uint8_t error, address;
+  int16_t nDevices;
+
+  counter++;
+  Serial.print(counter);
+  Serial.println(F(" Scanning..."));
+
+  nDevices = 0;
+  for (address = 1; address < 127; address++ )
+  {
+    // The i2c_scanner uses the return value of
+    // the Write.endTransmisstion to see if
+    // a device did acknowledge to the address.
+    Wire.beginTransmission(address);
+    error = Wire.endTransmission();
+
+    if (error == 0)
+    {
+      Serial.print(F("I2C device found at address 0x"));
+      if (address < 16)
+        Serial.print(F("0"));
+      Serial.println(address, HEX);
+      nDevices++;
+    }
+    else if (error == 4)
+    {
+      Serial.print(F("Unknown error at address 0x"));
+      if (address < 16)
+        Serial.print(F("0"));
+      Serial.println(address, HEX);
+    }
+  }
+
+  if (nDevices == 0)
+  {
+    Serial.println(F("No I2C devices found"));
+  }
+  else
+  {
+    Serial.println();
+    Serial.println(F("Done"));
+    Serial.println();
+  }
+
+  delay(5000);           // wait 5 seconds for next scan
+}