raspikeyer/src/keyer.cpp

#include <stdio.h>

#include "pico/stdlib.h"

#include "keyer.h"

extern const uint LED_PIN;
extern const uint LEFT_PADDLE_PIN;
extern const uint RIGHT_PADDLE_PIN;

bool left_paddle_pressed()
{
    if (!gpio_get(LEFT_PADDLE_PIN))
    {
        return true;
    }
    return false;
}

bool right_paddle_pressed()
{
    if (!gpio_get(RIGHT_PADDLE_PIN))
    {
        return true;
    }
    return false;
}

uint64_t calcElementDurationUs(uint8_t wpm)
{
    uint64_t duration = static_cast<uint64_t>(1.2 / static_cast<uint64_t>(wpm) * 1000 * 1000);
    return duration;
}

Keyer::Keyer(uint8_t wpm) : m_wpm(wpm)
{
    m_elementDuration = calcElementDurationUs(m_wpm);
}

void Keyer::run()
{
    auto timestamp = get_absolute_time();

    switch (state)
    {
    case State::Wait:
        if (left_paddle_pressed() && right_paddle_pressed())
        {
            if (m_lastSymbolWas == Symbol::Dit) {
                state = State::Dah;
            } else if (m_lastSymbolWas == Symbol::Dah) {
                state = State::Dit;
            }
            break;
        }
        if (left_paddle_pressed())
        {
            state = State::Dit;
        }
        else if (right_paddle_pressed())
        {
            state = State::Dah;
        }
        break;
    case State::Dit:
        if (!m_currentlyKeying)
        {
            m_currentlyKeying = true;
            m_keying_until = make_timeout_time_us(m_elementDuration);
            gpio_put(LED_PIN, 1);
            m_lastSymbolWas = Symbol::Dit;
        }
        else
        {
            if (absolute_time_diff_us(timestamp, m_keying_until) <= 0)
            {
                m_currentlyKeying = false;
                gpio_put(LED_PIN, 0);
                m_previousState = State::Dit;
                state = State::InterCharSpace;
            }
        }
        break;
    case State::Dah:
        if (!m_currentlyKeying)
        {
            m_currentlyKeying = true;
            m_keying_until = make_timeout_time_us(m_elementDuration * 3);
            gpio_put(LED_PIN, 1);
            m_lastSymbolWas = Symbol::Dah;
        }
        else
        {
            if (absolute_time_diff_us(timestamp, m_keying_until) <= 0)
            {
                m_currentlyKeying = false;
                gpio_put(LED_PIN, 0);
                m_previousState = State::Dah;
                state = State::InterCharSpace;
            }
        }
        break;
    case State::InterCharSpace:
        if (m_previousState != State::InterCharSpace)
        {
            m_pausing_until = make_timeout_time_us(m_elementDuration);
            m_previousState = State::InterCharSpace;
        }

        if (absolute_time_diff_us(timestamp, m_pausing_until) <= 0)
        {
            state = State::Wait;
        }

        break;

    default:
        break;
    }
}