From ca13033791da5450c199176358642839d7354e7b Mon Sep 17 00:00:00 2001
From: Ryan Monhollon <rotaryprophet@gmail.com>
Date: Wed, 22 Jul 2015 11:04:25 -0400
Subject: [PATCH] Add support for scroll functions

---
 Adafruit_RA8875.cpp        | 44 ++++++++++++++++++++++++++++++
 Adafruit_RA8875.h          | 10 +++++++
 examples/scroll/scroll.ino | 55 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 109 insertions(+)
 create mode 100644 examples/scroll/scroll.ino

diff --git a/Adafruit_RA8875.cpp b/Adafruit_RA8875.cpp
index 794609b..5f6a552 100644
--- a/Adafruit_RA8875.cpp
+++ b/Adafruit_RA8875.cpp
@@ -989,6 +989,50 @@ void Adafruit_RA8875::curveHelper(int16_t xCenter, int16_t yCenter, int16_t long
   waitPoll(RA8875_ELLIPSE, RA8875_ELLIPSE_STATUS);
 }
 
+void Adafruit_RA8875::setScrollWindow(int16_t x, int16_t y, int16_t w, int16_t h, uint8_t mode) {
+  // Horizontal Start point of Scroll Window
+  writeCommand(0x38);
+  writeData(x);
+  writeCommand(0x39);
+  writeData(x>>8);
+	
+  // Vertical Start Point of Scroll Window
+  writeCommand(0x3a);
+  writeData(y);
+  writeCommand(0x3b);
+  writeData(y>>8);
+	
+  // Horizontal End Point of Scroll Window
+  writeCommand(0x3c);
+  writeData(x+w);
+  writeCommand(0x3d);
+  writeData((x+w)>>8);
+  
+  // Vertical End Point of Scroll Window
+  writeCommand(0x3e);
+  writeData(y+h);
+  writeCommand(0x3f);
+  writeData((y+h)>>8);
+  
+  // Scroll function setting
+  writeCommand(0x52);
+  writeData(0x00);
+}
+
+void Adafruit_RA8875::scrollX(int16_t dist) {
+  writeCommand(0x24);
+  writeData(dist);
+  writeCommand(0x25);
+  writeData(dist>>8);
+}
+
+void Adafruit_RA8875::scrollY(int16_t dist) {
+  writeCommand(0x26);
+  writeData(dist);
+  writeCommand(0x27);
+  writeData(dist>>8);
+}
+
 /************************* Mid Level ***********************************/
 
 /**************************************************************************/
diff --git a/Adafruit_RA8875.h b/Adafruit_RA8875.h
index 82cd6a7..b651497 100644
--- a/Adafruit_RA8875.h
+++ b/Adafruit_RA8875.h
@@ -104,6 +104,11 @@ class Adafruit_RA8875 : public Adafruit_GFX {
   void    fillEllipse(int16_t xCenter, int16_t yCenter, int16_t longAxis, int16_t shortAxis, uint16_t color);
   void    drawCurve(int16_t xCenter, int16_t yCenter, int16_t longAxis, int16_t shortAxis, uint8_t curvePart, uint16_t color);
   void    fillCurve(int16_t xCenter, int16_t yCenter, int16_t longAxis, int16_t shortAxis, uint8_t curvePart, uint16_t color);
+
+  /* Scroll */
+  void    setScrollWindow(int16_t x, int16_t y, int16_t w, int16_t h, uint8_t mode);
+  void    scrollX(int16_t dist);
+  void    scrollY(int16_t dist);
   
   /* Backlight */
   void    GPIOX(boolean on);
@@ -359,4 +364,9 @@ class Adafruit_RA8875 : public Adafruit_GFX {
 #define RA8875_INTC2_TP         0x04
 #define RA8875_INTC2_BTE        0x02
 
+#define RA8875_SCROLL_BOTH	0x00
+#define RA8875_SCROLL_LAYER1	0x40
+#define RA8875_SCROLL_LAYER2	0x80
+#define RA8875_SCROLL_BUFFER	0xC0
+
 #endif
diff --git a/examples/scroll/scroll.ino b/examples/scroll/scroll.ino
new file mode 100644
index 0000000..2f94277
--- /dev/null
+++ b/examples/scroll/scroll.ino
@@ -0,0 +1,55 @@
+#include <SPI.h>
+#include <Wire.h>
+#include <EEPROM.h>
+#include "Adafruit_GFX.h"
+#include "Adafruit_RA8875.h"
+
+// LCD
+// Library only supports hardware SPI at this time
+// Connect SCLK to UNO Digital #13 (Hardware SPI clock)
+// Connect MISO to UNO Digital #12 (Hardware SPI MISO)
+// Connect MOSI to UNO Digital #11 (Hardware SPI MOSI)
+#define RA8875_INT     3
+#define RA8875_CS      10
+#define RA8875_RESET   9
+
+#define NUMINPUTS 4
+
+Adafruit_RA8875 tft = Adafruit_RA8875(RA8875_CS, RA8875_RESET);
+
+void setup() {
+  Serial.begin(9600);
+
+  if (!tft.begin(RA8875_800x480)) {
+    Serial.println("LCD not found!");
+    while (1);
+  }
+
+  tft.displayOn(true);
+  tft.GPIOX(true);      // Enable TFT - display enable tied to GPIOX
+  tft.PWM1config(true, RA8875_PWM_CLK_DIV1024); // PWM output for backlight
+  tft.PWM1out(255);
+
+  tft.fillScreen(RA8875_BLACK);
+  tft.setScrollWindow(0,0,800,480,RA8875_SCROLL_BOTH);
+  tft.fillCircle(690, 370, 100, RA8875_WHITE);
+}
+
+
+void loop() {
+  static int Scroll=0;
+  static int Dir=1;
+  
+  tft.scrollX(Scroll);
+  tft.scrollY(Scroll);
+  
+  Scroll+=Dir;
+  if(Scroll >= 250) {
+    Dir=-1;;
+  } else if(Scroll <= 0) {
+    Dir=1;
+  }
+
+  delay(10);
+}
+