Make hardware configurable

Move hardware-specifics (pin assignments, power management) to
hwconfig_*.py.

The build system will build a firmware image
firmware-filesystem-$variant.uf2 for all variants for which a
hwconfig_$variant.py file exits. Inside the filesystem image, the
selected variants hwconfig_$variant.py file will always be named
hwconfig.py.

At runtime, main.py will attempt to import hwconfig which will load the
configuration for the correct variant.

Currently, the hwconfig_* modules are expected to define the pin mapping
and implement a board_init method.

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

.gitea/workflows/build.yaml

@@ -1,6 +1,6 @@
 ---
 name: Build RPi Pico firmware image
-on:
+"on":
   push:
 
 jobs:
@@ -22,4 +22,4 @@ jobs:
         uses: actions/upload-artifact@v3
         with:
           name: firmware-RPi-Pico-W-with-fs
-          path: software/lib/micropython/ports/rp2/build-TONBERRY_RPI_PICO_W/firmware-filesystem.uf2
+          path: software/lib/micropython/ports/rp2/build-TONBERRY_RPI_PICO_W/firmware-filesystem-*.uf2

software/build.sh

@@ -27,12 +27,19 @@ fi
 BUILDDIR=lib/micropython/ports/rp2/build-TONBERRY_RPI_PICO_W/
 FS_STAGE_DIR=$(mktemp -d)
 trap 'rm -rf $FS_STAGE_DIR' EXIT
-find src/ -iname '*.py' | cpio -pdm "$FS_STAGE_DIR"
+for hwconfig in src/hwconfig_*.py; do
-tools/mklittlefs/mklittlefs -p 256 -s 868352 -c "$FS_STAGE_DIR"/src $BUILDDIR/filesystem.bin
+    hwconfig_base=$(basename "$hwconfig")
-truncate -s 2M $BUILDDIR/firmware-filesystem.bin
+    hwname=${hwconfig_base##hwconfig_}
-dd if=$BUILDDIR/firmware.bin of=$BUILDDIR/firmware-filesystem.bin bs=1k
+    hwname=${hwname%%.py}
-dd if=$BUILDDIR/filesystem.bin of=$BUILDDIR/firmware-filesystem.bin bs=1k seek=1200
+    find src/ -iname '*.py' \! -iname 'hwconfig_*.py' | cpio -pdm "$FS_STAGE_DIR"
-$PICOTOOL uf2 convert $BUILDDIR/firmware-filesystem.bin $BUILDDIR/firmware-filesystem.uf2
+    cp "$hwconfig" "$FS_STAGE_DIR"/src/hwconfig.py
+    tools/mklittlefs/mklittlefs -p 256 -s 868352 -c "$FS_STAGE_DIR"/src $BUILDDIR/filesystem.bin
+    truncate -s 2M $BUILDDIR/firmware-filesystem.bin
+    dd if=$BUILDDIR/firmware.bin of=$BUILDDIR/firmware-filesystem.bin bs=1k
+    dd if=$BUILDDIR/filesystem.bin of=$BUILDDIR/firmware-filesystem.bin bs=1k seek=1200
+    $PICOTOOL uf2 convert $BUILDDIR/firmware-filesystem.bin $BUILDDIR/firmware-filesystem-"$hwname".uf2
+    rm -r "${FS_STAGE_DIR:?}"/*
+done
 
 echo "Output in $BUILDDIR/firmware.uf2"
-echo "Image with filesystem in $BUILDDIR/firmware-filesystem.uf2"
+echo "Images with filesystem in" $BUILDDIR/firmware-filesystem-*.uf2

software/modules/audiocore/audiocore.py

@@ -1,12 +1,17 @@
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2025 Matthias Blankertz <matthias@blankertz.org>
+
 import _audiocore
 from asyncio import ThreadSafeFlag
+from utils import get_pin_index
 
 
 class Audiocore:
-    def __init__(self, pin, sideset):
+    def __init__(self, din, dclk, lrclk):
+        assert get_pin_index(lrclk) == get_pin_index(dclk)+1  # TODO: Support different pin arrangements
         self.notify = ThreadSafeFlag()
-        self.pin = pin
+        self.pin = din
-        self.sideset = sideset
+        self.sideset = dclk
         self._audiocore = _audiocore.Audiocore(self.pin, self.sideset, self._interrupt)
 
     def deinit(self):
@@ -40,12 +45,13 @@ class Audiocore:
 
 
 class AudioContext:
-    def __init__(self, pin, sideset):
+    def __init__(self, din, dclk, lrclk):
-        self.pin = pin
+        self.din = din
-        self.sideset = sideset
+        self.dclk = dclk
+        self.lrclk = lrclk
 
     def __enter__(self):
-        self._audiocore = Audiocore(self.pin, self.sideset)
+        self._audiocore = Audiocore(self.din, self.dclk, self.lrclk)
         return self._audiocore
 
     def __exit__(self, exc_type, exc_value, traceback):

software/src/hwconfig_Rev1.py

@@ -0,0 +1,63 @@
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2025 Matthias Blankertz <matthias@blankertz.org>
+
+import machine
+from machine import Pin
+
+# SD Card SPI
+SD_DI = Pin.board.GP3
+SD_DO = Pin.board.GP4
+SD_SCK = Pin.board.GP2
+SD_CS = Pin.board.GP5
+
+# MAX98357
+I2S_LRCLK = Pin.board.GP6
+I2S_DCLK = Pin.board.GP7
+I2S_DIN = Pin.board.GP8
+I2S_SD = Pin.board.GP9
+
+# RC522
+RC522_SPIID = 1
+RC522_RST = Pin.board.GP14
+RC522_IRQ = Pin.board.GP15
+RC522_MOSI = Pin.board.GP11
+RC522_MISO = Pin.board.GP12
+RC522_SCK = Pin.board.GP10
+RC522_SS = Pin.board.GP13
+
+# WS2812
+LED_DIN = Pin.board.GP16
+LED_COUNT = 1
+
+# Buttons
+BUTTON_VOLUP = Pin.board.GP17
+BUTTON_VOLDOWN = Pin.board.GP19
+BUTTON_NEXT = Pin.board.GP18
+BUTTON_POWER = Pin.board.GP21
+
+# Power
+POWER_EN = Pin.board.GP22
+VBAT_ADC = Pin.board.GP26
+
+
+def board_init():
+    # Keep power turned on
+    # TODO: Implement soft power off
+    POWER_EN.init(mode=Pin.OUTPUT)
+    POWER_EN.value(1)
+
+    # Set 8 mA drive strength and fast slew rate for SD SPI
+    machine.mem32[0x4001c004 + 6*4] = 0x67
+    machine.mem32[0x4001c004 + 7*4] = 0x67
+    machine.mem32[0x4001c004 + 8*4] = 0x67
+
+    # Permanently enable amplifier
+    # TODO: Implement amplifier power management
+    I2S_SD.init(mode=Pin.OPEN_DRAIN)
+    I2S_SD.value(1)
+
+
+def get_battery_voltage():
+    adc = machine.ADC(VBAT_ADC)     # create ADC object on ADC pin
+    battv = adc.read_u16()/65535.0*3.3*2
+    return battv

software/src/hwconfig_breadboard.py

@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2025 Matthias Blankertz <matthias@blankertz.org>
+
+import machine
+from machine import Pin
+
+# SD Card SPI
+SD_DI = Pin.board.GP3
+SD_DO = Pin.board.GP4
+SD_SCK = Pin.board.GP2
+SD_CS = Pin.board.GP5
+
+# MAX98357
+I2S_LRCLK = Pin.board.GP7
+I2S_DCLK = Pin.board.GP6
+I2S_DIN = Pin.board.GP8
+I2S_SD = None
+
+# RC522
+RC522_SPIID = 1
+RC522_RST = Pin.board.GP9
+RC522_IRQ = Pin.board.GP14
+RC522_MOSI = Pin.board.GP11
+RC522_MISO = Pin.board.GP12
+RC522_SCK = Pin.board.GP10
+RC522_SS = Pin.board.GP13
+
+# WS2812
+LED_DIN = Pin.board.GP16
+LED_COUNT = 1
+
+# Buttons
+BUTTON_VOLUP = Pin.board.GP17
+BUTTON_VOLDOWN = Pin.board.GP19
+BUTTON_NEXT = Pin.board.GP18
+BUTTON_POWER = None
+
+# Power
+POWER_EN = None
+VBAT_ADC = Pin.board.GP26
+
+
+def board_init():
+    # Set 8 mA drive strength and fast slew rate for SD SPI
+    machine.mem32[0x4001c004 + 6*4] = 0x67
+    machine.mem32[0x4001c004 + 7*4] = 0x67
+    machine.mem32[0x4001c004 + 8*4] = 0x67
+
+def get_battery_voltage():
+    # Not supported on breadboard
+    return None

software/src/main.py

@@ -18,14 +18,23 @@ from nfc import Nfc
 from rp2_neopixel import NeoPixel
 from utils import Buttons, SDContext, TimerManager
 
+try:
+    import hwconfig
+except ImportError:
+    print("Fatal: No hwconfig.py found")
+    raise
+
 micropython.alloc_emergency_exception_buf(100)
 
+# Machine setup
+hwconfig.board_init()
+
 
 async def rainbow(np, period=10):
     def gamma(value, X=2.2):
         return min(max(int(brightness * pow(value / 255.0, X) * 255.0 + 0.5), 0), 255)
 
-    brightness = 0.5
+    brightness = 0.05
     count = 0.0
     leds = len(np)
     while True:
@@ -34,7 +43,7 @@ async def rainbow(np, period=10):
             np[i] = (gamma((sin(ofs / leds * 2 * pi) + 1) * 127),
                      gamma((sin(ofs / leds * 2 * pi + 2/3*pi) + 1) * 127),
                      gamma((sin(ofs / leds * 2 * pi + 4/3*pi) + 1) * 127))
-        count += 0.2
+        count += 0.02 * leds
         before = time.ticks_ms()
         await np.async_write()
         now = time.ticks_ms()
@@ -42,12 +51,6 @@ async def rainbow(np, period=10):
             await asyncio.sleep_ms(20 - (now - before))
 
 
-# Machine setup
-
-# Set 8 mA drive strength and fast slew rate
-machine.mem32[0x4001c004 + 6*4] = 0x67
-machine.mem32[0x4001c004 + 7*4] = 0x67
-machine.mem32[0x4001c004 + 8*4] = 0x67
 # high prio for proc 1
 machine.mem32[0x40030000 + 0x00] = 0x10
 
@@ -55,21 +58,24 @@ machine.mem32[0x40030000 + 0x00] = 0x10
 def run():
     asyncio.new_event_loop()
     # Setup LEDs
-    pin = Pin.board.GP16
+    np = NeoPixel(hwconfig.LED_DIN, hwconfig.LED_COUNT, sm=1)
-    np = NeoPixel(pin, 10, sm=1)
     asyncio.create_task(rainbow(np))
 
     # Setup MP3 player
-    with SDContext(mosi=Pin(3), miso=Pin(4), sck=Pin(2), ss=Pin(5), baudrate=15000000), \
+    with SDContext(mosi=hwconfig.SD_DI, miso=hwconfig.SD_DO, sck=hwconfig.SD_SCK, ss=hwconfig.SD_CS,
-         AudioContext(Pin(8), Pin(6)) as audioctx:
+                   baudrate=15000000), \
+         AudioContext(hwconfig.I2S_DIN, hwconfig.I2S_DCLK, hwconfig.I2S_LRCLK) as audioctx:
 
         # Setup NFC
-        reader = MFRC522(spi_id=1, sck=10, miso=12, mosi=11, cs=13, rst=9, tocard_retries=20)
+        reader = MFRC522(spi_id=hwconfig.RC522_SPIID, sck=hwconfig.RC522_SCK, miso=hwconfig.RC522_MISO,
+                         mosi=hwconfig.RC522_MOSI, cs=hwconfig.RC522_SS, rst=hwconfig.RC522_RST, tocard_retries=20)
 
         # 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))
+                                buttons=lambda the_app: Buttons(the_app, pin_volup=hwconfig.BUTTON_VOLUP,
+                                                                pin_voldown=hwconfig.BUTTON_VOLDOWN,
+                                                                pin_next=hwconfig.BUTTON_NEXT))
         the_app = app.PlayerApp(deps)
 
         # Start
@@ -80,5 +86,5 @@ def run():
 
 if __name__ == '__main__':
     if machine.Pin(17, machine.Pin.IN, machine.Pin.PULL_UP).value() != 0:
-        time.sleep(5)
+        time.sleep(1)
         run()

software/src/utils/__init__.py

@@ -3,7 +3,8 @@
 
 from utils.buttons import Buttons
 from utils.mbrpartition import MBRPartition
+from utils.pinindex import get_pin_index
 from utils.sdcontext import SDContext
 from utils.timer import TimerManager
 
-__all__ = ["Buttons", "MBRPartition", "SDContext", "TimerManager"]
+__all__ = ["Buttons", "get_pin_index", "MBRPartition", "SDContext", "TimerManager"]

software/src/utils/pinindex.py

@@ -0,0 +1,43 @@
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2025 Matthias Blankertz <matthias@blankertz.org>
+
+from machine import Pin
+
+pins = [Pin.board.GP0,
+        Pin.board.GP1,
+        Pin.board.GP2,
+        Pin.board.GP3,
+        Pin.board.GP4,
+        Pin.board.GP5,
+        Pin.board.GP6,
+        Pin.board.GP7,
+        Pin.board.GP8,
+        Pin.board.GP9,
+        Pin.board.GP10,
+        Pin.board.GP11,
+        Pin.board.GP12,
+        Pin.board.GP13,
+        Pin.board.GP14,
+        Pin.board.GP15,
+        Pin.board.GP16,
+        Pin.board.GP17,
+        Pin.board.GP18,
+        Pin.board.GP19,
+        Pin.board.GP20,
+        Pin.board.GP21,
+        Pin.board.GP22,
+        None,  # 23
+        None,  # 24
+        None,  # 25
+        Pin.board.GP26,
+        Pin.board.GP27,
+        Pin.board.GP28,
+        ]
+
+
+def get_pin_index(pin: Pin) -> int:
+    """
+    Get the pin index back from a pin object.
+    Unfortunately, micropython has no built-in function for this.
+    """
+    return pins.index(pin)

software/tests/mocks/machine.py

@@ -1,2 +1,40 @@
 # SPDX-License-Identifier: MIT
 # Copyright (c) 2025 Matthias Blankertz <matthias@blankertz.org>
+
+class Pin:
+    def __init__(self, idx):
+        self.idx = idx
+
+    board = None
+
+
+class Board:
+    GP0 = Pin(0)
+    GP1 = Pin(1)
+    GP2 = Pin(2)
+    GP3 = Pin(3)
+    GP4 = Pin(4)
+    GP5 = Pin(5)
+    GP6 = Pin(6)
+    GP7 = Pin(7)
+    GP8 = Pin(8)
+    GP9 = Pin(9)
+    GP10 = Pin(10)
+    GP11 = Pin(11)
+    GP12 = Pin(12)
+    GP13 = Pin(13)
+    GP14 = Pin(14)
+    GP15 = Pin(15)
+    GP16 = Pin(16)
+    GP17 = Pin(17)
+    GP18 = Pin(18)
+    GP19 = Pin(19)
+    GP20 = Pin(20)
+    GP21 = Pin(21)
+    GP22 = Pin(22)
+    GP26 = Pin(26)
+    GP27 = Pin(27)
+    GP28 = Pin(28)
+
+
+Pin.board = Board