Wire Examples based on AVR ones of the same name (#5713)

* Wire Examples based on AVR ones of the same name

* Overload for begin(), change in callback arg from int to size_t

* Update master_reader.ino

Astyle

* Update master_writer.ino

Astyle

* Update slave_receiver.ino

Remove warning

* Update slave_receiver.ino

Astyle

libraries/Wire/examples/master_reader/master_reader.ino

@@ -0,0 +1,37 @@
+// Wire Master Reader
+// by devyte
+// based on the example of the same name by Nicholas Zambetti <http://www.zambetti.com>
+
+// Demonstrates use of the Wire library
+// Reads data from an I2C/TWI slave device
+// Refer to the "Wire Slave Sender" example for use with this
+
+// This example code is in the public domain.
+
+
+#include <Wire.h>
+#include <PolledTimeout.h>
+
+#define SDA_PIN 4
+#define SCL_PIN 5
+const int16_t I2C_MASTER = 0x42;
+const int16_t I2C_SLAVE = 0x08;
+
+void setup() {
+  Serial.begin(115200);  // start serial for output
+  Wire.begin(SDA_PIN, SCL_PIN, I2C_MASTER);        // join i2c bus (address optional for master)
+}
+
+void loop() {
+  using periodic = esp8266::polledTimeout::periodic;
+  static periodic nextPing(1000);
+
+  if (nextPing) {
+    Wire.requestFrom(I2C_SLAVE, 6);    // request 6 bytes from slave device #8
+
+    while (Wire.available()) { // slave may send less than requested
+      char c = Wire.read(); // receive a byte as character
+      Serial.print(c);         // print the character
+    }
+  }
+}