Initial commit with basic C code to write to pins.

compile

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+#!/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

main.c

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+#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);
+	}
+}

pins.c

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+#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);
+	}
+}

pins.h

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+#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