Adds Button class with support for software debouncing

lib/ESPboy/Button.cpp

@@ -0,0 +1,75 @@
+#include "Button.h"
+
+void Button::read(uint8_t input) {
+
+    for (uint8_t i = 0; i < 8; ++i) {
+
+        uint8_t reading = input & (1 << i);
+
+        /**
+         * Software debouncing algorithm (Kennet A. Kuhn)
+         * @see https://www.kennethkuhn.com/electronics/debounce.c
+         */
+             if (!reading) { if (_integrator[i]) _integrator[i]--; }
+        else if (_integrator[i] < _DEBOUNCING_THRESHOLD) _integrator[i]++;
+        uint8_t output = !_integrator[i] ? 0 : (_integrator[i] == _DEBOUNCING_THRESHOLD ? 1 : 0);
+
+        switch (_state[i])
+        {
+            case _State::FREE:
+                if (output) _state[i] = _State::PRESSED;
+                break;
+
+            case _State::PRESSED:
+                if (output) {
+                    _state[i] = _State::HELD;
+                    _held_start_ms[i] = millis();
+                } else _state[i] = _State::RELEASED;
+                break;
+
+            case _State::HELD:
+                if (!output) _state[i] = _State::RELEASED;
+                break;
+
+            case _State::RELEASED:
+                _state[i] = _State::FREE;
+                break;
+        }
+
+    }
+
+}
+
+bool Button::pressed(uint8_t button)  { return _state[button & 0x7] == _State::PRESSED;  }
+bool Button::released(uint8_t button) { return _state[button & 0x7] == _State::RELEASED; }
+
+bool Button::held(uint8_t button, uint32_t delay_ms) {
+
+    return _state[button & 0x7] == _State::HELD && (
+        delay_ms
+        ? millis() - _held_start_ms[button & 0x7] >= delay_ms
+        : true
+    );
+
+}
+
+/**
+ * ----------------------------------------------------------------------------
+ * First experiments with ESPboy2
+ * ----------------------------------------------------------------------------
+ * Copyright (c) 2021 Stéphane Calderoni (https://github.com/m1cr0lab)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ * ----------------------------------------------------------------------------
+ */

lib/ESPboy/Button.h

@@ -0,0 +1,54 @@
+#pragma once
+
+#include <Arduino.h>
+
+class Button {
+
+    private:
+
+        static constexpr uint8_t _DEBOUNCING_THRESHOLD = 3;
+
+        enum class _State : uint8_t { FREE, PRESSED, HELD, RELEASED };
+
+        _State   _state[8];
+        uint32_t _held_start_ms[8];
+        uint8_t  _integrator[8];
+
+    public:
+
+        static constexpr uint8_t LEFT      = 0;
+        static constexpr uint8_t UP        = 1;
+        static constexpr uint8_t DOWN      = 2;
+        static constexpr uint8_t RIGHT     = 3;
+        static constexpr uint8_t ACT       = 4;
+        static constexpr uint8_t ESC       = 5;
+        static constexpr uint8_t TOP_LEFT  = 6;
+        static constexpr uint8_t TOP_RIGHT = 7;
+
+        void read(uint8_t input);
+        bool pressed(uint8_t button);
+        bool released(uint8_t button);
+        bool held(uint8_t button, uint32_t delay_ms = 0);
+
+};
+
+/**
+ * ----------------------------------------------------------------------------
+ * First experiments with ESPboy2
+ * ----------------------------------------------------------------------------
+ * Copyright (c) 2021 Stéphane Calderoni (https://github.com/m1cr0lab)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ * ----------------------------------------------------------------------------
+ */

lib/ESPboy/ESPboy.cpp

@@ -30,6 +30,8 @@ void ESPboy::begin(bool show_logo) {
 }
 
 void ESPboy::update() {
+
+    button.read(~(_mcp.readGPIOAB() & 0xff));
 
     if (_fading.active) _fade();
 

lib/ESPboy/ESPboy.h

@@ -10,6 +10,7 @@
 #pragma once
 
 #include <Adafruit_MCP23X17.h>
+#include "Button.h"
 #include "NeoPixel.h"
 #include "lgfx.h"
 #include "espboy-logo.h"
@@ -46,6 +47,7 @@ class ESPboy {
     public:
 
         LGFX     tft;
+        Button   button;
         NeoPixel pixel;
 
         void begin(bool show_logo = true);

platformio.ini

@@ -63,6 +63,14 @@ src_filter = -<*> +<05-slide/*>
 board_build.f_cpu = 160000000L
 src_filter = -<*> +<06-jump/*>
 
+; ----------------------------------------------------------------------------
+; Improved button handling and support for software debouncing
+; ----------------------------------------------------------------------------
+
+[env:07-buttons]
+board_build.f_cpu = 160000000L
+src_filter = -<*> +<07-buttons.cpp>
+
 ; ----------------------------------------------------------------------------
 ; First experiments with ESPboy2
 ; ----------------------------------------------------------------------------

src/07-buttons.cpp

@@ -0,0 +1,75 @@
+/**
+ * ----------------------------------------------------------------------------
+ * Improved button handling and support for software debouncing
+ * ----------------------------------------------------------------------------
+ */
+#include <ESPboy.h>
+
+ESPboy espboy;
+LGFX_Sprite fb(&espboy.tft);
+
+uint16_t pressed  = 0;
+uint16_t held     = 0;
+uint16_t released = 0;
+
+void clear() { pressed = held = released = 0; }
+
+void setup() {
+
+    espboy.begin(false);
+    fb.createSprite(29, 31);
+
+    espboy.tft.setTextColor(TFT_LIGHTGRAY);
+    espboy.tft.drawCenterString("Press ACT", 64, 16);
+
+    espboy.tft.setTextColor(TFT_DARKGRAY);
+    espboy.tft.drawString("Pressed",  22, 40);
+    espboy.tft.drawString("Held",     22, 52);
+    espboy.tft.drawString("Released", 22, 64);
+
+    espboy.tft.setTextColor(TFT_LIGHTGRAY);
+    espboy.tft.drawCenterString("Reset by holding", 64, 88);
+    espboy.tft.drawCenterString("ESC down for 1 sec", 64, 100);
+
+}
+
+void loop() {
+
+    espboy.update();
+
+    fb.fillSprite(0);
+
+    if (espboy.button.pressed(Button::ACT))    pressed++;
+    if (espboy.button.held(Button::ACT))       held++;
+    if (espboy.button.released(Button::ACT)) { released++; held = 0; }
+
+    if (espboy.button.held(Button::ESC, 1000)) clear();
+
+    fb.drawNumber(pressed,  0, 0);
+    fb.drawNumber(held,     0, 12);
+    fb.drawNumber(released, 0, 24);
+
+    fb.pushSprite(82, 40);
+
+}
+
+/**
+ * ----------------------------------------------------------------------------
+ * First experiments with ESPboy2
+ * ----------------------------------------------------------------------------
+ * Copyright (c) 2021 Stéphane Calderoni (https://github.com/m1cr0lab)
+ * 
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ * 
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ * ----------------------------------------------------------------------------
+ */