update oled library, added oled rotate

Author: Heltec-Aaron-Lee

examples/OLED/OLED_rotate/OLED_rotate.ino

@@ -0,0 +1,99 @@
+
+#include "heltec.h"
+#include "Arduino.h"
+
+ SSD1306Wire display(0x3c, SDA_OLED, SCL_OLED, RST_OLED);
+
+void printBuffer(void) {
+  // Initialize the log buffer
+  // allocate memory to store 8 lines of text and 30 chars per line.
+  display.setLogBuffer(5, 30);
+
+  // Some test data
+  const char* test[] = {
+      "Hello",
+      "World" ,
+      "----",
+      "Show off",
+      "how",
+      "the log buffer",
+      "is",
+      "working.",
+      "Even",
+      "scrolling is",
+      "working"
+  };
+
+  for (uint8_t i = 0; i < 11; i++) {
+    display.clear();
+    // Print to the screen
+    display.println(test[i]);
+    // Draw it to the internal screen buffer
+    display.drawLogBuffer(0, 0);
+    // Display it on the screen
+    display.display();
+    delay(500);
+  }
+}
+
+void VextON(void)
+{
+  pinMode(Vext,OUTPUT);
+  digitalWrite(Vext, LOW);
+}
+
+void VextOFF(void) //Vext default OFF
+{
+  pinMode(Vext,OUTPUT);
+  digitalWrite(Vext, HIGH);
+}
+
+void setup() {
+
+  VextON();
+  delay(100);
+
+  display.init();
+  display.clear();
+  display.display();
+  
+  display.setContrast(255);
+
+  printBuffer();
+  delay(1000);
+
+  display.setTextAlignment(TEXT_ALIGN_CENTER);
+  display.clear();
+  display.display();
+  display.screenRotate(ANGLE_0_DEGREE);
+  display.setFont(ArialMT_Plain_16);
+  display.drawString(64, 32-16/2, "ROTATE_0");
+  display.display();
+  delay(2000);
+
+  display.clear();
+  display.display();
+  display.screenRotate(ANGLE_90_DEGREE);
+  display.setFont(ArialMT_Plain_10);
+  display.drawString(32, 64-10/2, "ROTATE_90");
+  display.display();
+  delay(2000);
+
+  display.clear();
+  display.display();
+  display.screenRotate(ANGLE_180_DEGREE);
+  display.setFont(ArialMT_Plain_16);
+  display.drawString(64, 32-16/2, "ROTATE_180");
+  display.display();
+  delay(2000);
+
+  display.clear();
+  display.display();
+  display.screenRotate(ANGLE_270_DEGREE);
+  display.setFont(ArialMT_Plain_10);
+  display.drawString(32, 64-10/2, "ROTATE_270");
+  display.display();
+  delay(2000);
+}
+
+void loop() { }