AVR EasyIO

AVR EasyIO is a lightweight utility header for simplifying GPIO, ADC and PWM operations in bare-metal AVR programming. It abstracts the verbose register manipulations into readable and efficient helper functions, without sacrificing performance or control.

Features

• pinMode() – Configure pins as INPUT, INPUT_PULLUP, or OUTPUT.
• digitalWrite() – Set digital pins HIGH or LOW.
• digitalRead() – Read digital pin values.
• analogRead() – Sample 10-bit analog values from ADC pins (0–5).
• setPWM() – Configure PWM on Timer0, Timer1, or Timer2 pins (e.g., PINB1, PINB2, PIND3, PIND5, PIND6, PINB3) with duty cycle control.

All functions operate directly on AVR registers for maximum speed and transparency.

Getting Started

Requirements

• AVR-GCC toolchain
• Supported AVR microcontroller (e.g. ATmega328P/PB)
• Optional: avrdude for flashing via ISP

Example Circuit

• Button connected to PIND7 (with internal pull-up)
• LED connected to PINB2 (PWM-capable, OC1B, Timer1) for brightness control
• Potentiometer connected to PINC0 (ADC0)

Example Code

See Examples/main.cpp for a minimal demonstration.

#define F_CPU 8000000UL
#include <util/delay.h>
#include "avr_easyio.h"

int main(void)
{
    pinMode(7, &DDRD, &PORTD, INPUT_PULLUP); // Configure button pin
    setPWM(PWM_PINB2, 0); // Initialize PWM on PB2 (LED off)

    while (1) {
        if (digitalRead(7, &DDRD, &PIND) == 0) { // Button pressed
            setPWM(PWM_PINB2, 255); // LED at full brightness
        } else {
            setPWM(PWM_PINB2, 64); // LED at ~25% brightness
        }

        uint16_t adcVal = analogRead(0, &DDRC, &PORTC); // Read potentiometer
        _delay_ms(50);
    }
}