Fastest sd clockrate possible with sandisk ultra 32gb card

The code snippet in hwconfig to adjust the drive strength was incorrect:
It was adjusting the wrong pins. This was probably not updated during
some pin shuffling in the breadboard phase.

Fix this by adjusting the correct pins. Experimentation shows that both
setting the slew rate to fast or setting the drive strength to 8 mA
(default: slow and 4 mA) is sufficient to make SD SPI work at 25 MHz on
the Rev1 PCB. For now, the combination 8 mA and slow is chosen (slow
slew rate should result in less high frequency EMI).

Also make the SD clock rate adjustable in hwconfig, and set it to 25 MHz
for Rev1 and 15 MHz for the breadboard setup.

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

hardware/tonberry-pico/Modules.pretty/Adafruit_bq25185.kicad_mod

@@ -341,15 +341,15 @@
 		(uuid "b2d6f12f-bf69-4a9b-a3e9-164231e4f483")
 	)
 	(embedded_fonts no)
-	(model "${KICAD9_3DMODEL_DIR}/Connector_PinSocket_2.54mm.3dshapes/PinSocket_1x07_P2.54mm_Vertical.step"
+	(model "${KICAD9_3DMODEL_DIR}/Connector_PinSocket_2.54mm.3dshapes/PinSocket_1x08_P2.54mm_Vertical.step"
 		(offset
-			(xyz 0 0 0)
+			(xyz 0 1.25 0)
 		)
 		(scale
 			(xyz 1 1 1)
 		)
 		(rotate
-			(xyz 0 0 0)
+			(xyz -0 -0 -0)
 		)
 	)
 )

hardware/tonberry-pico/tonberry-pico.kicad_pro

@@ -79,14 +79,6 @@
           "items_not_allowed|148720706|136551802|f2c1e20e-a272-42d8-a551-3e9074b96921|00000000-0000-0000-0000-000000000000",
           ""
         ],
-        [
-          "lib_footprint_mismatch|117348000|41148000|9810a3ba-e3fe-4afe-955a-bea6c56712c1|00000000-0000-0000-0000-000000000000",
-          ""
-        ],
-        [
-          "lib_footprint_mismatch|210176000|131198000|bf46a807-edd1-4c31-a613-56c8fe7b1e6b|00000000-0000-0000-0000-000000000000",
-          ""
-        ],
         [
           "nonmirrored_text_on_back_layer|210811000|131073000|e87ca627-5327-4f7e-ac1a-c1eadd662c0a|00000000-0000-0000-0000-000000000000",
           ""
@@ -177,7 +169,7 @@
         "min_track_width": 0.2032,
         "min_via_annular_width": 0.15,
         "min_via_diameter": 0.5,
-        "solder_mask_to_copper_clearance": 0.0,
+        "solder_mask_to_copper_clearance": 0.005,
         "use_height_for_length_calcs": true
       },
       "teardrop_options": [

software/CMakeLists.txt

@@ -54,9 +54,9 @@ add_subdirectory(modules/audiocore)
 
 add_custom_target(check-format
     find . -iname '*.[ch]' -exec clang-format -Werror --dry-run {} +
-    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/src
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/modules
 )
 add_custom_target(clang-format
     find . -iname '*.[ch]' -exec clang-format -i {} +
-    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/src
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/modules
 )

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"
-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 $BUILDDIR/firmware-filesystem.uf2
+for hwconfig in src/hwconfig_*.py; do
+    hwconfig_base=$(basename "$hwconfig")
+    hwname=${hwconfig_base##hwconfig_}
+    hwname=${hwname%%.py}
+    find src/ -iname '*.py' \! -iname 'hwconfig_*.py' | cpio -pdm "$FS_STAGE_DIR"
+    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/flash.sh

@@ -16,14 +16,15 @@ check_command lsusb
 check_command picotool
 
 DEVICEPATH=/dev/disk/by-label/RPI-RP2
-IMAGEPATH=lib/micropython/ports/rp2/build-TONBERRY_RPI_PICO_W/firmware.uf2
+IMAGEPATH=lib/micropython/ports/rp2/build-TONBERRY_RPI_PICO_W/
+REVISION=Rev1
 
 flash_via_mountpoint()
 {
     while [ ! -e "$DEVICEPATH" ] ; do sleep 1; echo 'Waiting for RP2...'; done
     
     udisksctl mount -b "$DEVICEPATH"
-    cp "$IMAGEPATH" "$(findmnt "$DEVICEPATH" -n -o TARGET)"
+    cp "$IMAGEFILE" "$(findmnt "$DEVICEPATH" -n -o TARGET)"
 }
 
 PID="2e8a"
@@ -40,7 +41,7 @@ flash_via_picotool()
     local device="${bus_device[1]//[!0-9]/}"
     echo "Found RP2 with serial $serial on Bus $bus Device $device"
     
-    picotool load --bus "$bus" --address "$device" "$IMAGEPATH" 
+    picotool load --bus "$bus" --address "$device" "$IMAGEFILE"
 }
 
 FLASH_VIA_MOUNTPOINT=0
@@ -52,11 +53,12 @@ usage()
     echo
     echo "  -m, --via-mountpoint    Mount first found RP2 and flash image by"
     echo "                          copying to mountpoint."
+    echo "  -r, --revision <rev>    Hardware revision to flash. Default is Rev1"
     echo "  -h, --help              Print this text and exit."
     exit 2
 }
 
-PARSED_ARGUMENTS=$(getopt -a -n "$0" -o mh --long via-mountpoint,help -- "$@")
+PARSED_ARGUMENTS=$(getopt -a -n "$0" -o mhr: --long via-mountpoint,revision:,help -- "$@")
 # shellcheck disable=SC2181
 # Indirect getopt return value checking is okay here
 if [ "$?" != "0" ]; then
@@ -68,6 +70,7 @@ while :
 do
     case "$1" in
         -m | --via-mountpoint)  FLASH_VIA_MOUNTPOINT=1      ; shift   ;;
+        -r | --revision)        REVISION=$2                 ; shift 2 ;;
         -h | --help)            usage                                 ;;
         --) shift; break ;;
         *) echo "Unexpected option: $1"
@@ -80,6 +83,8 @@ if [ $# -gt 0 ]; then
     usage
 fi
 
+IMAGEFILE="$IMAGEPATH"/firmware-filesystem-$REVISION.uf2
+
 if [ "$FLASH_VIA_MOUNTPOINT" -eq 0 ]; then
     flash_via_picotool
 else

software/modules/audiocore/audiocore.c

@@ -40,7 +40,7 @@ void __time_critical_func(core1_main)(void)
 {
     uint32_t ret = 0;
     bool running = true, playing = false;
-    if (!i2s_init(shared_context.out_pin, shared_context.sideset_base)) {
+    if (!i2s_init(shared_context.out_pin, shared_context.sideset_base, shared_context.sideset_dclk_first)) {
         ret = MP_EIO;
         goto out;
     }

software/modules/audiocore/audiocore.h

@@ -31,6 +31,7 @@ struct audiocore_shared_context {
 
     // Set by module.c before core1 is launched and then never changed, can be read without lock
     int out_pin, sideset_base, samplerate;
+    bool sideset_dclk_first;
 
     // Must hold lock. The indices 0..MP3_BUFFER_PREAREA-1 may only be read and written on core1 (no
     // lock needed) The buffer is aligned to, and MP3_BUFFER_PREAREA is a multiple of, the machine

software/modules/audiocore/audiocore.py

@@ -1,13 +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):
+        # PIO requires sideset pins to be adjacent
+        assert get_pin_index(lrclk) == get_pin_index(dclk)+1 or get_pin_index(lrclk) == get_pin_index(dclk)-1
         self.notify = ThreadSafeFlag()
-        self.pin = pin
-        self.sideset = sideset
-        self._audiocore = _audiocore.Audiocore(self.pin, self.sideset, self._interrupt)
+        self._audiocore = _audiocore.Audiocore(din, dclk, lrclk, self._interrupt)
 
     def deinit(self):
         self._audiocore.deinit()
@@ -40,12 +44,13 @@ class Audiocore:
 
 
 class AudioContext:
-    def __init__(self, pin, sideset):
-        self.pin = pin
-        self.sideset = sideset
+    def __init__(self, din, dclk, lrclk):
+        self.din = din
+        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/modules/audiocore/i2s.c

@@ -113,17 +113,18 @@ void i2s_stop(void)
     pio_sm_clear_fifos(audiocore_pio, i2s_context.pio_sm);
 }
 
-bool i2s_init(int out_pin, int sideset_base)
+bool i2s_init(int out_pin, int sideset_base, bool dclk_first)
 {
     memset(i2s_context.dma_buf, 0, sizeof(i2s_context.dma_buf[0][0]) * AUDIO_BUFS * I2S_DMA_BUF_SIZE);
-    if (!pio_can_add_program(audiocore_pio, (const pio_program_t *)&i2s_max98357_program))
+    const pio_program_t *program = dclk_first ? &i2s_max98357_program : &i2s_max98357_lrclk_program;
+    if (!pio_can_add_program(audiocore_pio, program))
         return false;
     i2s_context.pio_sm = pio_claim_unused_sm(audiocore_pio, false);
     i2s_context.out_pin = out_pin;
     i2s_context.sideset_base = sideset_base;
     if (i2s_context.pio_sm == -1)
         return false;
-    i2s_context.pio_program_offset = pio_add_program(audiocore_pio, (const pio_program_t *)&i2s_max98357_program);
+    i2s_context.pio_program_offset = pio_add_program(audiocore_pio, program);
 
     i2s_context.dma_ch = dma_claim_unused_channel(false);
     if (i2s_context.dma_ch == -1)

software/modules/audiocore/i2s.h

@@ -8,7 +8,7 @@
 
 #define I2S_DMA_BUF_SIZE (1152)
 
-bool i2s_init(int out_pin, int sideset_base);
+bool i2s_init(int out_pin, int sideset_base, bool dclk_first);
 void i2s_deinit(void);
 
 void i2s_play(int samplerate);

software/modules/audiocore/i2s_max98357.pio

@@ -10,7 +10,7 @@
 	.lang_opt python autopull = True
 	
 // data - DOUT
-// sideset - 2-BCLK, 1-LRCLK
+// sideset - 2-LRCLK, 1-BCLK
 
 	set	x,15			side 0
 	nop				side 1
@@ -33,6 +33,38 @@ right_loop:
 	set	x, 14			side 1
 	.wrap
 
+.program i2s_max98357_lrclk
+	.side_set 2
+
+	.lang_opt python sideset_init = pico.PIO.OUT_LOW
+	.lang_opt python out_init = pico.PIO.OUT_LOW
+	.lang_opt python out_shiftdir = pcio.PIO.SHIFT_LEFT
+	.lang_opt python autopull = True
+	
+// data - DOUT
+// sideset - 2-BCLK, 1-LRCLK
+
+	set	x,15			side 0
+	nop				side 2
+startup_loop:
+	nop				side 1
+	jmp	x-- startup_loop	side 3
+	nop				side 0
+	set	x, 14			side 2
+
+left_loop:
+	.wrap_target
+	out	pins, 1			side 0
+	jmp	x-- left_loop		side 2
+	out	pins, 1			side 1
+	set	x, 14			side 3
+right_loop:	
+	out	pins, 1			side 1
+	jmp	x-- right_loop		side 3
+	out	pins, 1			side 0
+	set	x, 14			side 2
+	.wrap
+
 % c-sdk {
 #include "hardware/clocks.h"
 

software/modules/audiocore/module.c

@@ -170,10 +170,11 @@ static MP_DEFINE_CONST_FUN_OBJ_2(audiocore_set_volume_obj, audiocore_set_volume)
  */
 static void audiocore_init(struct audiocore_obj *obj, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args)
 {
-    enum { ARG_pin, ARG_sideset, ARG_handler };
+    enum { ARG_pin, ARG_dclk, ARG_lrclk, ARG_handler };
     static const mp_arg_t allowed_args[] = {
         {MP_QSTR_pin, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
-        {MP_QSTR_sideset, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
+        {MP_QSTR_dclk, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
+        {MP_QSTR_lrclk, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
         {MP_QSTR_handler, MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL}},
     };
     if (initialized)
@@ -188,7 +189,8 @@ static void audiocore_init(struct audiocore_obj *obj, size_t n_args, const mp_ob
     mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
     mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
     const mp_hal_pin_obj_t pin = mp_hal_get_pin_obj(args[ARG_pin].u_obj);
-    const mp_hal_pin_obj_t sideset_pin = mp_hal_get_pin_obj(args[ARG_sideset].u_obj);
+    const mp_hal_pin_obj_t dclk_pin = mp_hal_get_pin_obj(args[ARG_dclk].u_obj);
+    const mp_hal_pin_obj_t lrclk_pin = mp_hal_get_pin_obj(args[ARG_lrclk].u_obj);
     if (args[ARG_handler].u_obj != MP_OBJ_NULL) {
         obj->irq_obj = mp_irq_new(&audiocore_irq_methods, MP_OBJ_FROM_PTR(obj));
         obj->irq_obj->handler = args[ARG_handler].u_obj;
@@ -203,7 +205,14 @@ static void audiocore_init(struct audiocore_obj *obj, size_t n_args, const mp_ob
     memset(shared_context.mp3_buffer, 0, MP3_BUFFER_PREAREA + MP3_BUFFER_SIZE);
     multicore_reset_core1();
     shared_context.out_pin = pin;
-    shared_context.sideset_base = sideset_pin;
+    // PIO requires sideset pins to be adjacent, but we support both dclk first and lrclk first
+    if (lrclk_pin == dclk_pin + 1) {
+        shared_context.sideset_base = dclk_pin;
+        shared_context.sideset_dclk_first = true;
+    } else {
+        shared_context.sideset_base = lrclk_pin;
+        shared_context.sideset_dclk_first = false;
+    }
     initialized = true;
     multicore_launch_core1(&core1_main);
     uint32_t result = get_fifo_read_value_blocking(obj);

software/modules/audiocore/test/test_audiocore.c

@@ -15,7 +15,7 @@ static unsigned multicore_fifo_push_last;
 
 static unsigned (*multicore_fifo_pop_blocking_cb)(void);
 
-bool i2s_init(int out_pin, int sideset_base)
+bool i2s_init(int out_pin, int sideset_base, bool dclk_first)
 {
     TEST_ASSERT_FALSE(i2s_initialized);
     if (i2s_init_return)

software/modules/rp2_sd/sd.c

@@ -23,7 +23,7 @@ static bool sd_acmd(const uint8_t cmd, const uint32_t arg, unsigned resplen, uin
 static bool sd_early_init(void)
 {
     uint8_t buf;
-    for (int i = 0; i < 5; ++i) {
+    for (int i = 0; i < 500; ++i) {
         if (sd_cmd(0, 0, 1, &buf)) {
 #ifdef SD_DEBUG
             printf("CMD0 resp %02hhx\n", buf);
@@ -63,7 +63,7 @@ static bool sd_send_op_cond(void)
 {
     uint8_t buf;
     bool use_acmd = true;
-    for (int timeout = 0; timeout < 500; ++timeout) {
+    for (int timeout = 0; timeout < 50000; ++timeout) {
         bool result = false;
         if (use_acmd)
             result = sd_acmd(41, 0x40000000, 1, &buf);
@@ -74,6 +74,7 @@ static bool sd_send_op_cond(void)
 #ifdef SD_DEBUG
                 printf("sd_init: card does not understand ACMD41, try CMD1...\n");
 #endif
+                use_acmd = false;
                 continue;
             } else if (buf != 0x01) {
                 printf("sd_init: send_op_cond failed\n");
@@ -174,6 +175,7 @@ static bool sd_read_csd(struct sd_context *sd_context)
         }
         }
         sd_context->blocks = blocks;
+        sd_context->blocksize = blocksize;
 #ifdef SD_DEBUG
         printf("CSD version %u.0, blocksize %u, blocks %u, capacity %llu MiB\n", version, blocksize, blocks,
                ((uint64_t)blocksize * blocks) / (1024 * 1024));
@@ -225,6 +227,26 @@ bool sd_init(struct sd_context *sd_context, int mosi, int miso, int sck, int ss,
         return false;
     }
 
+    if (sd_context->blocksize != SD_SECTOR_SIZE) {
+        if (sd_context->blocksize != 1024 && sd_context->blocksize != 2048) {
+            printf("sd_init: Unsupported block size %u\n", sd_context->blocksize);
+            return false;
+        }
+        // Attempt SET_BLOCKLEN command
+        uint8_t resp[1];
+        if (!sd_cmd(16, SD_SECTOR_SIZE, 1, resp)) {
+            printf("sd_init: SET_BLOCKLEN failed\n");
+            return false;
+        }
+        // Successfully set blocksize to SD_SECTOR_SIZE, adjust context
+        sd_context->blocks *= sd_context->blocksize / SD_SECTOR_SIZE;
+#ifdef SD_DEBUG
+        printf("Adjusted blocksize from %u to 512, card now has %u blocks\n", sd_context->blocksize,
+               sd_context->blocks);
+#endif
+        sd_context->blocksize = SD_SECTOR_SIZE;
+    }
+
 #ifdef SD_DEBUG
     sd_dump_cid();
 #endif
@@ -246,14 +268,24 @@ bool sd_readblock(struct sd_context *sd_context, size_t sector_num, uint8_t buff
     if (!sd_context->initialized || sector_num >= sd_context->blocks)
         return false;
 
-    return sd_cmd_read(17, sector_num, SD_SECTOR_SIZE, buffer);
+    uint32_t addr = sector_num;
+    if (!sd_context->sdhc_sdxc) {
+        // SDSC cards used byte addressing
+        addr *= SD_SECTOR_SIZE;
+    }
+    return sd_cmd_read(17, addr, SD_SECTOR_SIZE, buffer);
 }
 
 bool sd_readblock_start(struct sd_context *sd_context, size_t sector_num, uint8_t buffer[static SD_SECTOR_SIZE])
 {
     if (!sd_context->initialized || sector_num >= sd_context->blocks)
         return false;
-    return sd_cmd_read_start(17, sector_num, SD_SECTOR_SIZE, buffer);
+    uint32_t addr = sector_num;
+    if (!sd_context->sdhc_sdxc) {
+        // SDSC cards used byte addressing
+        addr *= SD_SECTOR_SIZE;
+    }
+    return sd_cmd_read_start(17, addr, SD_SECTOR_SIZE, buffer);
 }
 
 bool sd_readblock_complete(struct sd_context *sd_context)
@@ -271,5 +303,10 @@ bool sd_writeblock(struct sd_context *sd_context, size_t sector_num, uint8_t buf
     if (!sd_context->initialized || sector_num >= sd_context->blocks)
         return false;
 
-    return sd_cmd_write(24, sector_num, SD_SECTOR_SIZE, buffer);
+    uint32_t addr = sector_num;
+    if (!sd_context->sdhc_sdxc) {
+        // SDSC cards used byte addressing
+        addr *= SD_SECTOR_SIZE;
+    }
+    return sd_cmd_write(24, addr, SD_SECTOR_SIZE, buffer);
 }

software/modules/rp2_sd/sd.h

@@ -8,6 +8,7 @@
 
 struct sd_context {
     size_t blocks;
+    size_t blocksize;
     bool initialized;
     bool old_card;
     bool sdhc_sdxc;

software/src/hwconfig_Rev1.py

@@ -0,0 +1,65 @@
+# 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
+SD_CLOCKRATE = 16000000
+
+# 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.OUT)
+    POWER_EN.value(1)
+
+    # SD_DO / MISO input doesn't need any special configuration
+    # Set 8 mA drive strength for SCK and MOSI
+    machine.mem32[0x4001c004 + 2*4] = 0x71  # SCK
+    machine.mem32[0x4001c004 + 3*4] = 0x71  # MOSI
+    # SD_CS doesn't need any special configuration
+
+    # 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 +1,49 @@
+# SPDX-License-Identifier: MIT
+# Copyright (c) 2025 Matthias Blankertz <matthias@blankertz.org>
+
+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
+SD_CLOCKRATE = 15000000
+
+# 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():
+    pass
+
+
+def get_battery_voltage():
+    # Not supported on breadboard
+    return None

software/src/main.py

@@ -6,7 +6,6 @@ import asyncio
 import machine
 import micropython
 import time
-from machine import Pin
 from math import pi, sin, pow
 
 # Own modules
@@ -18,14 +17,23 @@ 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 +42,7 @@ 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 +50,6 @@ 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 +57,24 @@ machine.mem32[0x40030000 + 0x00] = 0x10
 def run():
     asyncio.new_event_loop()
     # Setup LEDs
-    pin = Pin.board.GP16
-    np = NeoPixel(pin, 10, sm=1)
+    np = NeoPixel(hwconfig.LED_DIN, hwconfig.LED_COUNT, 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), \
-         AudioContext(Pin(8), Pin(6)) as audioctx:
+    with SDContext(mosi=hwconfig.SD_DI, miso=hwconfig.SD_DO, sck=hwconfig.SD_SCK, ss=hwconfig.SD_CS,
+                   baudrate=hwconfig.SD_CLOCKRATE), \
+         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 +85,5 @@ 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