From 1dc500a0020a42baf949f8c893084faf3d9865a8 Mon Sep 17 00:00:00 2001
From: Jim Martens <github@2martens.de>
Date: Thu, 25 Jun 2015 11:27:07 +0200
Subject: [PATCH] [ES] Aufgabe 5.1 angefangen

Signed-off-by: Jim Martens <github@2martens.de>
---
 es/blatt5/uebung5-1/uebung5-1.ino | 126 ++++++++++++++++++++++++++++++
 1 file changed, 126 insertions(+)
 create mode 100644 es/blatt5/uebung5-1/uebung5-1.ino

diff --git a/es/blatt5/uebung5-1/uebung5-1.ino b/es/blatt5/uebung5-1/uebung5-1.ino
new file mode 100644
index 0000000..f5a0788
--- /dev/null
+++ b/es/blatt5/uebung5-1/uebung5-1.ino
@@ -0,0 +1,126 @@
+#include <SPI.h>
+
+// pins
+int slaveSelectPin = 10;
+int rstPin = 6;
+int dcPin = 5;
+
+// constants
+int divider = 84;
+int maxBufferIndex = 288;
+
+// buffer
+char screenBuffer[288];
+
+void setup()
+{
+    Serial.begin(9600);
+    
+    // intialize SPI
+    SPI.begin(slaveSelectPin);
+    SPI.setClockDivider(slaveSelectPin, divider);
+    
+    // initialize pins
+    pinMode(dcPin, OUTPUT);
+    pinMode(rstPin, OUTPUT);
+    
+    // initial reset of display
+    resetDisplay();
+    
+    // initialization of display
+    digitalWrite(dcPin, LOW);
+    SPI.transfer(slaveSelectPin, 0x21);
+    SPI.transfer(slaveSelectPin, 0x14);
+    SPI.transfer(slaveSelectPin, 0xb0);
+    SPI.transfer(slaveSelectPin, 0x20);
+    SPI.transfer(slaveSelectPin, 0x0c);
+    digitalWrite(dcPin, HIGH);
+    
+    // initialize screen buffer
+    for (int i = 0; i < maxBufferIndex; i++) {
+      screenBuffer[i] = 0x0;
+    }
+}
+
+/**
+ * Loop function for main code
+ */
+void loop()
+{
+  for (int y = 0; y < 84; y++) {
+    for (int x = 0; x < 48; x++) {
+      setPixel(x, y, 1);
+    }
+    flushBuffer();
+    delay(20);
+  }
+  //flushBuffer();
+  //delay(20);
+  Serial.println("fertig");
+  
+}
+
+void resetDisplay()
+{
+  digitalWrite(rstPin, LOW);
+  delay(500);
+  digitalWrite(rstPin, HIGH);
+}
+
+void flushBuffer()
+{
+  for (int i = 0; i < maxBufferIndex; i++) {
+    SPI.transfer(slaveSelectPin, screenBuffer[i]);
+  }
+}
+
+/**
+ * Sets the pixel at the given location.
+ * @param x
+ * @param y
+ * @param value
+ */
+void setPixel(int x, int y, int value)
+{
+  int bank = x / 8;
+  int relativeRow = x - bank * 8;
+  int bankStartIndex = bank * 48;
+  int index = bankStartIndex + y;
+  char bitValue = 0x0;
+  
+  if (value == 1) {
+    bitValue = 0xff;
+  }
+  
+  char existingValue = screenBuffer[index];
+  char pixelMask = 1 << relativeRow;
+  pixelMask = 0x0 | pixelMask;
+  char invMask = ~ pixelMask;
+  char newValue = pixelMask & bitValue;
+  
+  char finalExistingValue = existingValue & invMask;
+  char finalValue = finalExistingValue | newValue;
+
+  Serial.print("bank:");
+  Serial.println(bank);
+  Serial.print("relRow:");
+  Serial.println(relativeRow);  
+  Serial.print("index:");
+  Serial.println(index);
+  Serial.print("value:");
+  Serial.println(value);
+  Serial.print("existingValue:");
+  Serial.println(existingValue, BIN);
+  Serial.print("finalExistingValue:");
+  Serial.println(finalExistingValue, BIN);
+  Serial.print("pixelMask:");
+  Serial.println(pixelMask, BIN);
+  Serial.print("invMask:");
+  Serial.println(invMask, BIN);
+  Serial.print("newValue:");
+  Serial.println(newValue, BIN);
+  Serial.print("finalValue:");
+  Serial.println(finalValue, BIN);
+  Serial.println("-----");
+  screenBuffer[index] = finalValue;
+}