Add support for character input ('A', 'B', 'C') in isPressed() (#33)

* feat(buttons): allow isPressed() to accept 'A', 'B', 'C' as input

Added support for character and string-based input to `isPressed()` in `ModulinoButtons`,
so it now accepts both index (0–2) and letter identifiers (`'A'`, `'B'`, `'C'`) matching
the physical button labeling.

Closes #3

* Update example to document support for both numeric and letter indices ♻️

* Update API docs ♻️

* Delete .gitignore

* Update examples/Modulino_Buttons/Buttons_Basic/Buttons_Basic.ino

---------

Co-authored-by: Leonardo Cavagnis <45899760+leonardocavagnis@users.noreply.github.com>

Author: AntonioBerna

docs/api.md

@@ -33,6 +33,12 @@ Represents a Modulino Buttons module.
 - **`PinStatus isPressed(int index)`**  
   Returns the press status (HIGH/LOW) of the button at the specified index (_0-A, 1-B, 2-C_).
 
+- **`PinStatus isPressed(char button)`**  
+  Returns the press status (HIGH/LOW) of the button specified by its character ('A', 'B', 'C').
+
+- **`PinStatus isPressed(const char *button)`**
+  Returns the press status (HIGH/LOW) of the button specified by its string ("A", "B", "C").
+
 - **`bool update()`**  
   Updates the button status. Returns `true` if the status has changed, `false` otherwise.
 

examples/Modulino_Buttons/Buttons_Basic/Buttons_Basic.ino

@@ -24,22 +24,24 @@ void setup() {
   // Turn on the LEDs above buttons A, B, and C
   buttons.setLeds(true, true, true);
 }
+
 void loop() {
   // Check for new button events, returns true when button state changes
   if (buttons.update()) {
-    // Check which button was pressed (0=A, 1=B, 2=C)
-    // Also toggle the corresponding LED, for each of the three buttons
-    if (buttons.isPressed(0)) {
+    // You can use either index (0=A, 1=B, 2=C) or letter ('A', 'B', 'C') to check buttons
+    // Below we use the letter-based method for better readability
+
+    if (buttons.isPressed('A')) {
       Serial.println("Button A pressed!");
       button_a = !button_a;
-    } else if (buttons.isPressed(1)) {
+    } else if (buttons.isPressed("B")) {
       Serial.println("Button B pressed!");
       button_b = !button_b;
-    } else if (buttons.isPressed(2)) {
+    } else if (buttons.isPressed('C')) {
       Serial.println("Button C pressed!");
       button_c = !button_c;
     }
-    
+
     // Update the LEDs above buttons, depending on the variables value
     buttons.setLeds(button_a, button_b, button_c);
   }

src/Modulino.h

@@ -127,6 +127,17 @@ class ModulinoButtons : public Module {
   PinStatus isPressed(int index) {
     return last_status[index] ? HIGH : LOW;
   }
+  PinStatus isPressed(char button) {
+    int index = buttonToIndex(button);
+    if (index < 0) return LOW;
+    return isPressed(index);
+  }
+  PinStatus isPressed(const char *button) {
+    if (button == nullptr || button[0] == '\0' || button[1] != '\0') {
+      return LOW;
+    }
+    return isPressed(button[0]);
+  }
   bool update() {
     uint8_t buf[3];
     auto res = read((uint8_t*)buf, 3);
@@ -154,6 +165,14 @@ class ModulinoButtons : public Module {
   }
 private:
   bool last_status[3];
+  int buttonToIndex(char button) {
+    switch (toupper(button)) {
+      case 'A': return 0;
+      case 'B': return 1;
+      case 'C': return 2;
+      default:  return -1;
+    }
+  }
 protected:
   uint8_t match[1] = { 0x7C };  // same as fw main.c
 };