feat: Make button mapping configurable

- Remove Pin to button mapping from hwconfig, replace with a simple list
  of Pins to which buttons are attached
- Add BUTTON_MAP to config.json which maps indices in the HW button list
  to button names
- Update utils.Buttons to use the button map to connect the correct pins
  to the matching key codes

Signed-off-by: Matthias Blankertz <matthias@blankertz.org>

software/src/hwconfig_Rev1/hwconfig.py

@@ -30,10 +30,12 @@ RC522_SS = Pin.board.GP13
 LED_DIN = Pin.board.GP16
 
 # Buttons
-BUTTON_VOLUP = Pin.board.GP17
-BUTTON_VOLDOWN = Pin.board.GP19
-BUTTON_NEXT = Pin.board.GP18
-BUTTON_POWER = Pin.board.GP21
+BUTTONS = [Pin.board.GP17,
+           Pin.board.GP18,
+           Pin.board.GP19,
+           Pin.board.GP20,
+           Pin.board.GP21,
+           ]
 
 # Power
 POWER_EN = Pin.board.GP22

software/src/hwconfig_breadboard/hwconfig.py

@@ -29,10 +29,10 @@ RC522_SS = Pin.board.GP13
 LED_DIN = Pin.board.GP16
 
 # Buttons
-BUTTON_VOLUP = Pin.board.GP17
-BUTTON_VOLDOWN = Pin.board.GP19
-BUTTON_NEXT = Pin.board.GP18
-BUTTON_POWER = None
+BUTTONS = [Pin.board.GP17,
+           Pin.board.GP18,
+           Pin.board.GP19,
+           ]
 
 # Power
 POWER_EN = None

software/src/main.py

@@ -89,9 +89,7 @@ def run():
             # Setup app
             deps = app.Dependencies(mp3player=lambda the_app: MP3Player(audioctx, the_app),
                                     nfcreader=lambda the_app: Nfc(reader, the_app),
-                                    buttons=lambda the_app: Buttons(the_app, pin_volup=hwconfig.BUTTON_VOLUP,
-                                                                    pin_voldown=hwconfig.BUTTON_VOLDOWN,
-                                                                    pin_next=hwconfig.BUTTON_NEXT),
+                                    buttons=lambda the_app: Buttons(the_app, config, hwconfig),
                                     playlistdb=lambda _: playlistdb,
                                     hwconfig=lambda _: hwconfig,
                                     leds=lambda _: LedManager(np),
@@ -124,5 +122,5 @@ def builddb():
 
 if __name__ == '__main__':
     time.sleep(1)
-    if machine.Pin(hwconfig.BUTTON_VOLUP, machine.Pin.IN, machine.Pin.PULL_UP).value() != 0:
+    if machine.Pin(hwconfig.BUTTONS[0], machine.Pin.IN, machine.Pin.PULL_UP).value() != 0:
         run()

software/src/utils/buttons.py

@@ -17,14 +17,27 @@ if TYPE_CHECKING:
 
 
 class Buttons:
-    def __init__(self, cb: "ButtonCallback", pin_volup=17, pin_voldown=19, pin_next=18):
-        self.VOLUP = micropython.const(1)
-        self.VOLDOWN = micropython.const(2)
-        self.NEXT = micropython.const(3)
+    VOLUP = micropython.const(1)
+    VOLDOWN = micropython.const(2)
+    NEXT = micropython.const(3)
+    PREV = micropython.const(4)
+    PLAY_PAUSE = micropython.const(5)
+    KEYMAP = {VOLUP: 'VOLUP',
+              VOLDOWN: 'VOLDOWN',
+              NEXT: 'NEXT',
+              PREV: 'PREV',
+              PLAY_PAUSE: 'PLAY_PAUSE'}
+
+    def __init__(self, cb: "ButtonCallback", config, hwconfig):
+        self.button_map = config.get_button_map()
+        self.hw_buttons = hwconfig.BUTTONS
         self.cb = cb
-        self.buttons = {machine.Pin(pin_volup, machine.Pin.IN, machine.Pin.PULL_UP): self.VOLUP,
-                        machine.Pin(pin_voldown, machine.Pin.IN, machine.Pin.PULL_UP): self.VOLDOWN,
-                        machine.Pin(pin_next, machine.Pin.IN, machine.Pin.PULL_UP): self.NEXT}
+        self.buttons = dict()
+        for key_id, key_name in self.KEYMAP.items():
+            pin = self._get_pin(key_name)
+            if pin is None:
+                continue
+            self.buttons[pin] = key_id
         self.int_flag = asyncio.ThreadSafeFlag()
         self.pressed: list[int] = []
         self.last: dict[int, int] = {}
@@ -32,6 +45,17 @@ class Buttons:
             button.irq(handler=self._interrupt, trigger=machine.Pin.IRQ_FALLING | machine.Pin.IRQ_RISING)
         asyncio.create_task(self.task())
 
+    def _get_pin(self, key):
+        key_id = self.button_map.get(key, None)
+        if key_id is None:
+            return None
+        if key_id < 0 or key_id >= len(self.hw_buttons):
+            return None
+        pin = self.hw_buttons[key_id]
+        if pin is not None:
+            pin.init(machine.Pin.IN, machine.Pin.PULL_UP)
+        return pin
+
     def _interrupt(self, button):
         keycode = self.buttons[button]
         last = self.last.get(keycode, 0)

software/src/utils/config.py

@@ -4,6 +4,10 @@
 from errno import ENOENT
 import json
 import os
+try:
+    from typing import TYPE_CHECKING, Mapping
+except ImportError:
+    TYPE_CHECKING = False
 
 
 class Configuration:
@@ -11,6 +15,13 @@ class Configuration:
         'LED_COUNT': 1,
         'IDLE_TIMEOUT_SECS': 60,
         'TAG_TIMEOUT_SECS': 5,
+        'BUTTON_MAP': {
+            'PLAY_PAUSE': 4,
+            'VOLUP': 0,
+            'VOLDOWN': 2,
+            'PREV': None,
+            'NEXT': 1,
+        }
     }
 
     def __init__(self, config_path='/config.json'):
@@ -49,11 +60,14 @@ class Configuration:
     def _get(self, key):
         return self.config.get(key, self.DEFAULT_CONFIG[key])
 
-    def get_led_count(self):
+    def get_led_count(self) -> int:
         return self._get('LED_COUNT')
 
-    def get_idle_timeout(self):
+    def get_idle_timeout(self) -> int:
         return self._get('IDLE_TIMEOUT_SECS')
 
-    def get_tag_timeout(self):
+    def get_tag_timeout(self) -> int:
         return self._get('TAG_TIMEOUT_SECS')
+
+    def get_button_map(self) -> Mapping[str, int | None]:
+        return self._get('BUTTON_MAP')