commit c358ee6a05a1963b39944cbb4ccc58293228cad6
Author: Marvin Blum <marvin@marvinblum.de>
Date:   Thu Mar 9 23:30:15 2017 +0100

    Initial commit with basic C code to write to pins.

diff --git a/compile b/compile
new file mode 100755
index 0000000..557efb9
--- /dev/null
+++ b/compile
@@ -0,0 +1,9 @@
+#!/bin/bash
+
+mkdir build
+avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/pins.o -Wall pins.c
+avr-gcc -Os -DF_CPU=16000000UL -mmcu=atmega328p -c -o build/main.o -Wall main.c
+avr-gcc -mmcu=atmega328p build/main.o build/pins.o -o build/main
+avr-objcopy -O ihex -R .eeprom build/main build/main.hex
+avrdude -F -V -c arduino -p ATMEGA328P -P $1 -b 57600 -U flash:w:build/main.hex
+rm -r build
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..77784b3
--- /dev/null
+++ b/main.c
@@ -0,0 +1,12 @@
+#include <avr/io.h>
+#include <util/delay.h>
+#include "pins.h"
+
+int main(){
+	while(1){
+		digitalWrite(5, HIGH);
+		_delay_ms(1000);
+		digitalWrite(5, LOW);
+		_delay_ms(1000);
+	}
+}
diff --git a/pins.c b/pins.c
new file mode 100644
index 0000000..8ef18af
--- /dev/null
+++ b/pins.c
@@ -0,0 +1,53 @@
+#include "pins.h"
+#include <avr/io.h>
+
+const unsigned char LOW = 0x00;
+const unsigned char HIGH = 0x01;
+
+void digitalWrite(unsigned char pin, unsigned char value){
+	if(pin > 13){
+		return;
+	}
+
+	// TODO turn off pwm
+
+	if(pin < 8){
+		// pin 0-7
+		DDRD |= _BV(DDD0+pin);
+
+		if(value == HIGH){
+			PORTD |= _BV(DDD0+pin);
+		}
+		else{
+			PORTD &= ~_BV(DDD0+pin);
+		}
+	}
+	else{
+		// pin 8-13
+		DDRB |= _BV(DDB0+pin);
+
+		if(value == HIGH){
+			PORTB |= _BV(DDB0+pin);
+		}
+		else{
+			PORTB &= ~_BV(DDB0+pin);
+		}
+	}
+}
+
+void analogWrite(unsigned char pin, unsigned char value){
+	if(pin > 7){
+		return;
+	}
+
+	// TODO turn off pwm
+
+	DDRC |= _BV(DDC0+pin);
+
+	if(value == HIGH){
+		PORTC |= _BV(DDC0+pin);
+	}
+	else{
+		PORTC &= ~_BV(DDC0+pin);
+	}
+}
\ No newline at end of file
diff --git a/pins.h b/pins.h
new file mode 100644
index 0000000..4af9988
--- /dev/null
+++ b/pins.h
@@ -0,0 +1,10 @@
+#ifndef PINS_H_
+#define PINS_H_
+
+extern const unsigned char LOW;
+extern const unsigned char HIGH;
+
+void digitalWrite(unsigned char, unsigned char);
+void analogWrite(unsigned char, unsigned char);
+
+#endif