1 files changed, 102 insertions, 0 deletions
diff --git a/src/gpio.cc b/src/gpio.cc
new file mode 100644
index 0000000..23fc6dc
--- /dev/null
+++ b/src/gpio.cc
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2016 by Daniel Friesel
+ *
+ * License: You may use, redistribute and/or modify this file under the terms
+ * of either:
+ * * The GNU LGPL v3 (see COPYING and COPYING.LESSER), or
+ * * The 3-clause BSD License (see COPYING.BSD)
+ *
+ */
+
+#include <avr/io.h>
+#include <stdlib.h>
+
+#include "gpio.h"
+
+GPIO gpio;
+
+void GPIO::pinMode(const uint8_t pin, uint8_t mode)
+{
+	/*
+	 * pin is const, so this switch statement is optimized out by the
+	 * compiler. If mode is also a literal, the function call will also
+	 * be optimized out, resulting in just 2 Bytes per pinMode call.
+	 */
+	switch (pin) {
+		case 1:
+			if (mode == 1)
+				DDRC |= _BV(PC0);
+			else
+				DDRC &= ~_BV(PC0);
+		break;
+		case 2:
+			if (mode == 1)
+				DDRC |= _BV(PC1);
+			else
+				DDRC &= ~_BV(PC1);
+		break;
+		case 3:
+			if (mode == 1)
+				DDRC |= _BV(PC2);
+			else
+				DDRC &= ~_BV(PC2);
+		break;
+		case 4:
+			if (mode == 1)
+				DDRA |= _BV(PA1);
+			else
+				DDRA &= ~_BV(PA1);
+		break;
+	}
+}
+
+void GPIO::digitalWrite(const uint8_t pin, uint8_t value)
+{
+	/*
+	 * will be optimized out -- see above
+	 */
+	switch (pin) {
+		case 1:
+			if (value == 1)
+				PORTC |= _BV(PC0);
+			else
+				PORTC &= ~_BV(PC0);
+		break;
+		case 2:
+			if (value == 1)
+				PORTC |= _BV(PC1);
+			else
+				PORTC &= ~_BV(PC1);
+		break;
+		case 3:
+			if (value == 1)
+				PORTC |= _BV(PC2);
+			else
+				PORTC &= ~_BV(PC2);
+		break;
+		case 4:
+			if (value == 1)
+				PORTA |= _BV(PA1);
+			else
+				PORTA &= ~_BV(PA1);
+		break;
+	}
+}
+
+uint8_t GPIO::digitalRead(const uint8_t pin)
+{
+	/*
+	 * will be optimized out -- see above
+	 */
+	switch (pin) {
+		case 1:
+			return (PINC & _BV(PC0));
+		case 2:
+			return (PINC & _BV(PC1));
+		case 3:
+			return (PINC & _BV(PC2));
+		case 4:
+			return (PINA & _BV(PA1));
+	}
+	return 0;
+}