add MIDI support

CMakeLists.txt

@@ -40,6 +40,13 @@ target_sources(drumkit PUBLIC
     src/pulse.c
     src/sequence.c
     src/ui.c
+    src/log.c
+    src/ring.c
+    src/console.c
+    src/usb.c
+    src/usb_cdc.c
+    src/usb_descriptors.c
+    src/usb_midi.c
 
     pico-ssd1306/ssd1306.c
 )
@@ -73,6 +80,9 @@ target_link_libraries(drumkit
     hardware_adc
     hardware_gpio
     hardware_pwm
+    pico_unique_id
+    tinyusb_device
+    tinyusb_board
 )
 
 # enable usb output, disable uart output
@@ -83,3 +93,10 @@ pico_enable_stdio_uart(drumkit 0)
 target_compile_definitions(drumkit PUBLIC PICO_RP2040_USB_DEVICE_ENUMERATION_FIX=1)
 
 pico_add_extra_outputs(drumkit)
+
+# print binary size
+# https://github.com/raspberrypi/pico-sdk/issues/1196#issuecomment-1429404558
+add_custom_command(TARGET drumkit
+    POST_BUILD
+    COMMAND ${PICO_GCC_TRIPLE}-size --format=gnu ${CMAKE_CURRENT_BINARY_DIR}/drumkit.elf
+)

debug.sh

@@ -18,7 +18,7 @@
 
 set -euo pipefail
 
-SERIAL=/dev/serial/by-id/usb-Raspberry_Pi_Pico_*
+SERIAL=/dev/serial/by-id/usb-xythobuz_LARS_*
 
 echo -n Waiting for serial port to appear
 until [ -e $SERIAL ]

flash.sh

@@ -18,7 +18,7 @@
 
 set -euo pipefail
 
-SERIAL=/dev/serial/by-id/usb-Raspberry_Pi_Pico_*
+SERIAL=/dev/serial/by-id/usb-xythobuz_LARS_*
 DISK=/dev/disk/by-label/RPI-RP2
 MOUNT=/mnt/tmp
 

include/console.h

@@ -0,0 +1,26 @@
+/*
+ * console.h
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __CONSOLE_H__
+#define __CONSOLE_H__
+
+void cnsl_init(void);
+void cnsl_run(void);
+void cnsl_handle_input(const void *buf, size_t len);
+
+#endif // __CONSOLE_H__

include/log.h

@@ -0,0 +1,56 @@
+/*
+ * log.h
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __LOG_H__
+#define __LOG_H__
+
+#include <stdarg.h>
+#include <stdbool.h>
+#include <inttypes.h>
+#include "pico/stdlib.h"
+
+// for output that is stored in the debug log.
+// will be re-played from buffer when terminal connects
+#ifndef PICOWOTA
+#define debug(fmt, ...) debug_log(true, \
+        "%08" PRIu32 " %s:%d: " fmt "\r\n", \
+        to_ms_since_boot(get_absolute_time()), \
+        __func__, __LINE__, \
+        ##__VA_ARGS__)
+#else // PICOWOTA
+#define debug(fmt, ...) debug_log(true, \
+        fmt "\r\n", \
+        ##__VA_ARGS__)
+#endif // PICOWOTA
+
+// for interactive output. is not stored or re-played.
+#define print(fmt, ...) debug_log(false, fmt, ##__VA_ARGS__)
+#define println(fmt, ...) debug_log(false, fmt "\r\n", ##__VA_ARGS__)
+
+void debug_log(bool log, const char *format, ...) __attribute__((format(printf, 2, 3)));
+void debug_wait_input(const char *format, ...) __attribute__((format(printf, 1, 2)));
+void debug_log_va(bool log, const char *format, va_list args);
+
+void log_dump_to_usb(void);
+
+void debug_handle_input(const void *buff, size_t len);
+
+#include "ring.h"
+struct ring_buffer *log_get(void);
+
+#endif // __LOG_H__

include/main.h

@@ -27,6 +27,9 @@ enum hw_versions {
 
 extern enum hw_versions hw_type;
 
-void handle_serial_input(void);
+void main_loop_hw(void);
+
+void reset_to_bootloader(void);
+void reset_to_main(void);
 
 #endif // __MAIN_H__

include/ring.h

@@ -0,0 +1,45 @@
+/*
+ * ring.h
+ *
+ * Copyright (c) 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __RING_BUFFER_H__
+#define __RING_BUFFER_H__
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+struct ring_buffer {
+    void *buffer;
+    size_t size;
+    size_t el_len;
+    size_t head, tail;
+    bool full;
+};
+#define RB_INIT(b, s, e) { .buffer = b, .size = s, .el_len = e, .head = 0, .tail = 0, .full = false }
+
+void rb_add(struct ring_buffer *rb, const void *data, size_t length);
+#define rb_push(rb, v) rb_add(rb, v, 1)
+size_t rb_len(struct ring_buffer *rb);
+#define rb_space(rb) ((rb)->size - rb_len(rb))
+void rb_dump(struct ring_buffer *rb, void (*write)(const void *, size_t), size_t skip);
+void rb_move(struct ring_buffer *rb, void (*write)(const void *, size_t));
+void rb_peek(struct ring_buffer *rb, void *buf);
+void rb_pop(struct ring_buffer *rb, void *buf);
+size_t rb_get(struct ring_buffer *rb, void *data, size_t length);
+
+#endif // __RING_BUFFER_H__

include/sequence.h

@@ -44,6 +44,7 @@ void sequence_init(void);
 void sequence_set_bpm(uint32_t new_bpm);
 uint32_t sequence_get_bpm(void);
 
+void sequence_set_ms(uint32_t new_ms);
 uint32_t sequence_get_ms(void);
 
 void sequence_set_beats(uint32_t new_beats);

include/tusb_config.h

@@ -0,0 +1,129 @@
+/*
+ * Extended from TinyUSB example code.
+ *
+ * Copyright (c) 2022 - 2024 Thomas Buck (thomas@xythobuz.de)
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#ifndef _TUSB_CONFIG_H_
+#define _TUSB_CONFIG_H_
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+//--------------------------------------------------------------------
+// COMMON CONFIGURATION
+//--------------------------------------------------------------------
+
+// defined by board.mk
+#ifndef CFG_TUSB_MCU
+  #error CFG_TUSB_MCU must be defined
+#endif
+
+// RHPort number used for device can be defined by board.mk, default to port 0
+#ifndef BOARD_DEVICE_RHPORT_NUM
+  #define BOARD_DEVICE_RHPORT_NUM     0
+#endif
+
+// RHPort max operational speed can defined by board.mk
+// Default to Highspeed for MCU with internal HighSpeed PHY (can be port specific), otherwise FullSpeed
+#ifndef BOARD_DEVICE_RHPORT_SPEED
+  #if (CFG_TUSB_MCU == OPT_MCU_LPC18XX || CFG_TUSB_MCU == OPT_MCU_LPC43XX || CFG_TUSB_MCU == OPT_MCU_MIMXRT10XX || \
+       CFG_TUSB_MCU == OPT_MCU_NUC505  || CFG_TUSB_MCU == OPT_MCU_CXD56 || CFG_TUSB_MCU == OPT_MCU_SAMX7X)
+    #define BOARD_DEVICE_RHPORT_SPEED   OPT_MODE_HIGH_SPEED
+  #else
+    #define BOARD_DEVICE_RHPORT_SPEED   OPT_MODE_FULL_SPEED
+  #endif
+#endif
+
+// Device mode with rhport and speed defined by board.mk
+#if   BOARD_DEVICE_RHPORT_NUM == 0
+  #define CFG_TUSB_RHPORT0_MODE     (OPT_MODE_DEVICE | BOARD_DEVICE_RHPORT_SPEED)
+#elif BOARD_DEVICE_RHPORT_NUM == 1
+  #define CFG_TUSB_RHPORT1_MODE     (OPT_MODE_DEVICE | BOARD_DEVICE_RHPORT_SPEED)
+#else
+  #error "Incorrect RHPort configuration"
+#endif
+
+#ifndef CFG_TUSB_OS
+#define CFG_TUSB_OS               OPT_OS_NONE
+#endif
+
+// CFG_TUSB_DEBUG is defined by compiler in DEBUG build
+// #define CFG_TUSB_DEBUG           0
+
+/* USB DMA on some MCUs can only access a specific SRAM region with restriction on alignment.
+ * Tinyusb use follows macros to declare transferring memory so that they can be put
+ * into those specific section.
+ * e.g
+ * - CFG_TUSB_MEM SECTION : __attribute__ (( section(".usb_ram") ))
+ * - CFG_TUSB_MEM_ALIGN   : __attribute__ ((aligned(4)))
+ */
+#ifndef CFG_TUSB_MEM_SECTION
+#define CFG_TUSB_MEM_SECTION
+#endif
+
+#ifndef CFG_TUSB_MEM_ALIGN
+#define CFG_TUSB_MEM_ALIGN          __attribute__ ((aligned(4)))
+#endif
+
+//--------------------------------------------------------------------
+// DEVICE CONFIGURATION
+//--------------------------------------------------------------------
+
+#ifndef CFG_TUD_ENDPOINT0_SIZE
+#define CFG_TUD_ENDPOINT0_SIZE    64
+#endif
+
+//------------- CLASS -------------//
+#define CFG_TUD_HID               0
+#define CFG_TUD_CDC               1
+#define CFG_TUD_MSC               0
+#define CFG_TUD_MIDI              1
+#define CFG_TUD_VENDOR            0
+
+// HID buffer size Should be sufficient to hold ID (if any) + Data
+#define CFG_TUD_HID_EP_BUFSIZE    16
+
+// CDC FIFO size of TX and RX
+#define CFG_TUD_CDC_RX_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+#define CFG_TUD_CDC_TX_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
+// CDC Endpoint transfer buffer size, more is faster
+#define CFG_TUD_CDC_EP_BUFSIZE   (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
+// MIDI FIFO size of TX and RX
+#define CFG_TUD_MIDI_RX_BUFSIZE  (TUD_OPT_HIGH_SPEED ? 512 : 64)
+#define CFG_TUD_MIDI_TX_BUFSIZE  (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
+// MIDI Endpoint transfer buffer size, more is faster
+#define CFG_TUD_CDC_MIDI_BUFSIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif /* _TUSB_CONFIG_H_ */

include/ui.h

@@ -21,18 +21,10 @@
 
 #include <stdint.h>
 
-enum ui_modes {
-    UI_MODE = 0,
-    UI_BPM,
-    UI_BANK,
-    UI_LENGTH,
-
-    UI_NUM_MODES
-};
-
 enum machine_modes {
     MODE_LOOPSTATION = 0,
     MODE_DRUMMACHINE,
+    MODE_MIDI,
 
     MACHINE_NUM_MODES
 };
@@ -41,6 +33,8 @@ void ui_init(void);
 void ui_encoder(int32_t val);
 void ui_run(void);
 
+void ui_midi_set(uint8_t channel, uint8_t note, uint8_t velocity);
+
 enum machine_modes ui_get_machinemode(void);
 
 #endif // __UI_H__

include/usb.h

@@ -0,0 +1,29 @@
+/*
+ * usb.h
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __USB_H__
+#define __USB_H__
+
+#include <stdbool.h>
+
+void usb_init(void);
+void usb_run(void);
+
+bool usb_is_connected(void);
+
+#endif // __USB_H__

include/usb_cdc.h

@@ -0,0 +1,29 @@
+/*
+ * usb_cdc.h
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __USB_CDC_H__
+#define __USB_CDC_H__
+
+#include <stddef.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+void usb_cdc_write(const void *buf, size_t count);
+void usb_cdc_set_reroute(bool reroute);
+
+#endif // __USB_CDC_H__

include/usb_descriptors.h

@@ -0,0 +1,28 @@
+/*
+ * usb_descriptors.h
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef USB_DESCRIPTORS_H_
+#define USB_DESCRIPTORS_H_
+
+#include "pico/unique_id.h"
+
+extern char string_pico_serial[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1];
+
+void usb_descriptor_init_id(void);
+
+#endif /* USB_DESCRIPTORS_H_ */

include/usb_midi.h

@@ -0,0 +1,30 @@
+/*
+ * usb_midi.h
+ *
+ * Copyright (c) 2024 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __USB_MIDI_H__
+#define __USB_MIDI_H__
+
+#include <stdint.h>
+
+#define MIDI_MAX_CH 16
+
+void usb_midi_tx(uint8_t channel, uint8_t note, uint8_t velocity);
+
+void usb_midi_run(void);
+
+#endif // __USB_MIDI_H__

src/console.c

@@ -0,0 +1,187 @@
+/*
+ * console.c
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdio.h>
+
+#include "pico/stdlib.h"
+#include "hardware/watchdog.h"
+
+#include "log.h"
+#include "usb_cdc.h"
+#include "main.h"
+#include "console.h"
+
+#define CNSL_BUFF_SIZE 64
+#define CNSL_REPEAT_MS 500
+
+static char cnsl_line_buff[CNSL_BUFF_SIZE + 1];
+static uint32_t cnsl_buff_pos = 0;
+
+static char cnsl_last_command[CNSL_BUFF_SIZE + 1];
+
+static char cnsl_repeated_command[CNSL_BUFF_SIZE + 1];
+static bool repeat_command = false;
+static uint32_t last_repeat_time = 0;
+
+static void cnsl_interpret(const char *line) {
+    if (strlen(line) == 0) {
+        if ((strlen(cnsl_last_command) > 0) && (strcmp(cnsl_last_command, "repeat") != 0)) {
+            // repeat last command once
+            println("repeating command \"%s\"", cnsl_last_command);
+            cnsl_interpret(cnsl_last_command);
+            println();
+        }
+        return;
+    } else if (strcmp(line, "repeat") == 0) {
+        if (!repeat_command) {
+            // mark last command to be repeated multiple times
+            strncpy(cnsl_repeated_command, cnsl_last_command, CNSL_BUFF_SIZE + 1);
+            last_repeat_time = to_ms_since_boot(get_absolute_time()) - 1001;
+            repeat_command = true;
+        } else {
+            // stop repeating
+            repeat_command = false;
+        }
+    } else if ((strcmp(line, "help") == 0)
+            || (strcmp(line, "h") == 0)
+            || (strcmp(line, "?") == 0)) {
+        println("LARS Firmware Usage:");
+        println("");
+        println("  reset - reset back into this firmware");
+        println("   \\x18 - reset to bootloader");
+        println(" repeat - repeat last command every %d milliseconds", CNSL_REPEAT_MS);
+        println("   help - print this message");
+        println("");
+        println("Press Enter with no input to repeat last command.");
+        println("Use repeat to continuously execute last command.");
+        println("Stop this by calling repeat again.");
+    } else if (strcmp(line, "reset") == 0) {
+        reset_to_main();
+    } else {
+        println("unknown command \"%s\"", line);
+    }
+
+    println();
+}
+
+void cnsl_init(void) {
+    cnsl_buff_pos = 0;
+    for (int i = 0; i < CNSL_BUFF_SIZE + 1; i++) {
+        cnsl_line_buff[i] = '\0';
+        cnsl_last_command[i] = '\0';
+        cnsl_repeated_command[i] = '\0';
+    }
+}
+
+static int32_t cnsl_find_line_end(void) {
+    for (uint32_t i = 0; i < cnsl_buff_pos; i++) {
+        if ((cnsl_line_buff[i] == '\r') || (cnsl_line_buff[i] == '\n')) {
+            return i;
+        }
+    }
+    return -1;
+}
+
+void cnsl_run(void) {
+    if (repeat_command && (strlen(cnsl_repeated_command) > 0)
+            && (strcmp(cnsl_repeated_command, "repeat") != 0)) {
+        uint32_t now = to_ms_since_boot(get_absolute_time());
+        if (now >= (last_repeat_time + CNSL_REPEAT_MS)) {
+            println("repeating command \"%s\"", cnsl_repeated_command);
+            cnsl_interpret(cnsl_repeated_command);
+            println();
+
+            last_repeat_time = now;
+        }
+    } else {
+        if (repeat_command) {
+            println("nothing to repeat");
+        }
+        repeat_command = false;
+    }
+}
+
+void cnsl_handle_input(const void *buf, size_t len) {
+    if ((cnsl_buff_pos + len) > CNSL_BUFF_SIZE) {
+        debug("error: console input buffer overflow! %lu > %u", cnsl_buff_pos + len, CNSL_BUFF_SIZE);
+        cnsl_init();
+    }
+
+    memcpy(cnsl_line_buff + cnsl_buff_pos, buf, len);
+    cnsl_buff_pos += len;
+
+    // handle backspace and local echo
+    for (ssize_t i = cnsl_buff_pos - len; i < (ssize_t)cnsl_buff_pos; i++) {
+        if ((cnsl_line_buff[i] == '\b') || (cnsl_line_buff[i] == 0x7F)) {
+            if (i > 0) {
+                // overwrite previous character and backspace
+                for (ssize_t j = i; j < (ssize_t)cnsl_buff_pos - 1; j++) {
+                    cnsl_line_buff[j - 1] = cnsl_line_buff[j + 1];
+                }
+                cnsl_buff_pos -= 2;
+            } else {
+                // just remove the backspace
+                for (ssize_t j = i; j < (ssize_t)cnsl_buff_pos - 1; j++) {
+                    cnsl_line_buff[j] = cnsl_line_buff[j + 1];
+                }
+                cnsl_buff_pos -= 1;
+            }
+
+            usb_cdc_write((const uint8_t *)"\b \b", 3);
+
+#ifndef NDEBUG
+            serial_write((const uint8_t *)"\b \b", 3);
+#endif
+
+            // check for another backspace in this space
+            i--;
+        } else {
+            usb_cdc_write((const uint8_t *)(cnsl_line_buff + i), 1);
+
+#ifndef NDEBUG
+            serial_write((const uint8_t *)(cnsl_line_buff + i), 1);
+#endif
+        }
+    }
+
+    int32_t line_len = cnsl_find_line_end();
+    if (line_len < 0) {
+        // user has not pressed enter yet
+        return;
+    }
+
+    // convert line to C-style string
+    cnsl_line_buff[line_len] = '\0';
+
+    cnsl_interpret(cnsl_line_buff);
+
+    // store command for eventual repeats
+    strncpy(cnsl_last_command, cnsl_line_buff, CNSL_BUFF_SIZE + 1);
+
+    // clear string and move following data over
+    uint32_t cnt = line_len + 1;
+    if (cnsl_line_buff[line_len + 1] == '\n') {
+        cnt++;
+    }
+    memset(cnsl_line_buff, '\0', cnt);
+    memmove(cnsl_line_buff, cnsl_line_buff + cnt, sizeof(cnsl_line_buff) - cnt);
+    cnsl_buff_pos -= cnt;
+}

src/lcd.c

@@ -17,11 +17,14 @@
  */
 
 #include "hardware/i2c.h"
+#include "hardware/watchdog.h"
 
 #include "ssd1306.h"
 
 #include "buttons.h"
+#include "console.h"
 #include "main.h"
+#include "usb.h"
 #include "lcd.h"
 
 static i2c_inst_t *gpio_i2c_proto = i2c0;
@@ -45,8 +48,10 @@ void lcd_debug_buttons(void) {
     buttons_callback(lcd_debug_buttons_callback);
 
     while (1) {
+        watchdog_update();
         buttons_run();
-        handle_serial_input();
+        usb_run();
+        cnsl_run();
 
         if (changed) {
             changed = false;

src/log.c

@@ -0,0 +1,113 @@
+/*
+ * log.c
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include "hardware/watchdog.h"
+
+#include "main.h"
+#include "usb_cdc.h"
+#include "ring.h"
+#include "log.h"
+
+static uint8_t log_buff[4096] = {0};
+static struct ring_buffer log_rb = RB_INIT(log_buff, sizeof(log_buff), 1);
+
+static uint8_t line_buff[256] = {0};
+static volatile bool got_input = false;
+
+static void add_to_log(const void *buff, size_t len) {
+    rb_add(&log_rb, buff, len);
+}
+
+struct ring_buffer *log_get(void) {
+    return &log_rb;
+}
+
+static void log_dump_to_x(void (*write)(const void *, size_t)) {
+    if (rb_len(&log_rb) == 0) {
+        return;
+    }
+
+    int l = snprintf((char *)line_buff, sizeof(line_buff), "\r\n\r\nbuffered log output:\r\n");
+    if ((l > 0) && (l <= (int)sizeof(line_buff))) {
+        write(line_buff, l);
+    }
+
+    rb_dump(&log_rb, write, 0);
+
+    l = snprintf((char *)line_buff, sizeof(line_buff), "\r\n\r\nlive log:\r\n");
+    if ((l > 0) && (l <= (int)sizeof(line_buff))) {
+        write(line_buff, l);
+    }
+}
+
+void log_dump_to_usb(void) {
+    log_dump_to_x(usb_cdc_write);
+}
+
+void debug_log_va(bool do_log, const char *format, va_list args) {
+    int l = vsnprintf((char *)line_buff, sizeof(line_buff), format, args);
+
+    if (l < 0) {
+        // encoding error
+        l = snprintf((char *)line_buff, sizeof(line_buff), "%s: encoding error\r\n", __func__);
+    } else if (l >= (ssize_t)sizeof(line_buff)) {
+        // not enough space for string
+        l = snprintf((char *)line_buff, sizeof(line_buff), "%s: message too long (%d)\r\n", __func__, l);
+    }
+    if ((l > 0) && (l <= (int)sizeof(line_buff))) {
+        usb_cdc_write(line_buff, l);
+
+        if (do_log) {
+            add_to_log(line_buff, l);
+        }
+    }
+}
+
+void debug_log(bool do_log, const char* format, ...) {
+    va_list args;
+    va_start(args, format);
+    debug_log_va(do_log, format, args);
+    va_end(args);
+}
+
+void debug_handle_input(const void *buff, size_t len) {
+    (void)buff;
+
+    if (len > 0) {
+        got_input = true;
+    }
+}
+
+void debug_wait_input(const char *format, ...) {
+    va_list args;
+    va_start(args, format);
+    debug_log_va(false, format, args);
+    va_end(args);
+
+    got_input = false;
+    usb_cdc_set_reroute(true);
+
+    while (!got_input) {
+        main_loop_hw();
+    }
+
+    usb_cdc_set_reroute(false);
+}

src/main.c

@@ -16,20 +16,22 @@
  * See <http://www.gnu.org/licenses/>.
  */
 
-#include <stdio.h>
 #include "pico/stdlib.h"
 #include "pico/bootrom.h"
 #include "hardware/watchdog.h"
 
 #include "adc.h"
 #include "buttons.h"
+#include "console.h"
 #include "encoder.h"
 #include "lcd.h"
 #include "led.h"
+#include "log.h"
 #include "logo.h"
 #include "pulse.h"
 #include "sequence.h"
 #include "ui.h"
+#include "usb.h"
 #include "main.h"
 
 #define WATCHDOG_PERIOD_MS 100
@@ -45,7 +47,7 @@ static void debug_buttons_callback(enum buttons btn, bool v) {
     debug_buttons[btn] = v;
 }
 
-static void reset_to_bootloader(void) {
+void reset_to_bootloader(void) {
     lcd_draw_bye();
 
 #ifdef PICO_DEFAULT_LED_PIN
@@ -55,17 +57,46 @@ static void reset_to_bootloader(void) {
 #endif // PICO_DEFAULT_LED_PIN
 }
 
-void handle_serial_input(void) {
-    int c = getchar_timeout_us(0);
-    if (c == 0x18) {
-        reset_to_bootloader();
-    } else if (c != PICO_ERROR_TIMEOUT) {
-        printf("%c", c);
+void reset_to_main(void) {
+    watchdog_enable(1, 0);
+    while (1);
+}
+
+static void encoder_handle(void) {
+    static int32_t last_epos = 0;
+    int32_t epos = encoder_pos();
+    if (epos != last_epos) {
+        ui_encoder(epos - last_epos);
+        last_epos = epos;
     }
 }
 
+static void sleep_ms_wd(uint32_t ms) {
+    for (uint32_t i = 0; i < ms; i++) {
+        watchdog_update();
+        sleep_ms(1);
+    }
+}
+
+void main_loop_hw(void) {
+    watchdog_update();
+
+    usb_run();
+    cnsl_run();
+    buttons_run();
+    encoder_run();
+    sequence_run();
+    pulse_run();
+    ui_run();
+
+    encoder_handle();
+}
+
 int main(void) {
-    stdio_init_all();
+    watchdog_enable(WATCHDOG_PERIOD_MS, 1);
+
+    cnsl_init();
+    usb_init();
 
     gpio_init(gpio_hw_detect);
     gpio_set_dir(gpio_hw_detect, GPIO_IN);
@@ -90,9 +121,11 @@ int main(void) {
     // read out button state for debug options
     buttons_callback(debug_buttons_callback);
     for (uint i = 0; i < (DEBOUNCE_DELAY_MS + 5); i++) {
+        watchdog_update();
         buttons_run();
-        handle_serial_input();
-        sleep_ms(1);
+        usb_run();
+        cnsl_run();
+        sleep_ms_wd(1);
     }
 
     // handle special button combos on boot
@@ -108,8 +141,10 @@ int main(void) {
         uint32_t last = to_ms_since_boot(get_absolute_time());
         bool state = false;
         while (debug_buttons[BTN_CLICK]) {
+            watchdog_update();
             buttons_run();
-            handle_serial_input();
+            usb_run();
+            cnsl_run();
             uint32_t now = to_ms_since_boot(get_absolute_time());
             if ((now - last) >= 250) {
                 state = !state;
@@ -120,9 +155,11 @@ int main(void) {
     } else {
         // show splash for a bit and animate LEDs
         for (uint i = 0; i < LED_COUNT; i++) {
-            handle_serial_input();
+            watchdog_update();
+            usb_run();
+            cnsl_run();
             led_set(i, true);
-            sleep_ms(LOGO_INIT_MS / LED_COUNT);
+            sleep_ms_wd(LOGO_INIT_MS / LED_COUNT);
         }
     }
 
@@ -134,26 +171,10 @@ int main(void) {
     sequence_init();
     ui_init();
 
-    printf("init done\n");
-    watchdog_enable(WATCHDOG_PERIOD_MS, 1);
-
-    int32_t last_epos = 0;
+    debug("init done\n");
 
     while (1) {
-        watchdog_update();
-        buttons_run();
-        encoder_run();
-        sequence_run();
-        pulse_run();
-        ui_run();
-
-        int32_t epos = encoder_pos();
-        if (epos != last_epos) {
-            ui_encoder(epos - last_epos);
-            last_epos = epos;
-        }
-
-        handle_serial_input();
+        main_loop_hw();
     }
 
     return 0;

src/ring.c

@@ -0,0 +1,111 @@
+/*
+ * ring.c
+ *
+ * Copyright (c) 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * 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.
+ *
+ * See <http://www.gnu.org/licenses/>.
+ */
+
+#define MIN(x, y) ((x < y) ? x : y)
+
+#include <string.h>
+
+#include "ring.h"
+
+void rb_add(struct ring_buffer *rb, const void *data, size_t length) {
+    for (size_t i = 0; i < length; i++) {
+        memcpy(rb->buffer + rb->head * rb->el_len, data + i * rb->el_len, rb->el_len);
+
+        if (rb->full && (++(rb->tail) == rb->size)) {
+            rb->tail = 0;
+        }
+
+        if (++(rb->head) == rb->size) {
+            rb->head = 0;
+        }
+
+        rb->full = ((rb->head) == (rb->tail));
+    }
+}
+
+size_t rb_len(struct ring_buffer *rb) {
+    if (rb->head == rb->tail) {
+        if (rb->full) {
+            return rb->size;
+        } else {
+            return 0;
+        }
+    } else if (rb->head > rb->tail) {
+        return rb->head - rb->tail;
+    } else {
+        return rb->size - rb->tail + rb->head;
+    }
+}
+
+void rb_dump(struct ring_buffer *rb, void (*write)(const void *, size_t), size_t skip) {
+    if (rb_len(rb) <= skip) {
+        return;
+    }
+
+    if (rb->head > rb->tail) {
+        if ((rb->head - rb->tail) > skip) {
+            write(rb->buffer + ((rb->tail + skip) * rb->el_len), rb->head - rb->tail - skip);
+        }
+    } else {
+        if ((rb->size - rb->tail) > skip) {
+            write(rb->buffer + ((rb->tail + skip) * rb->el_len), rb->size - rb->tail - skip);
+        }
+
+        skip -= MIN(skip, rb->size - rb->tail);
+        if (rb->head > skip) {
+            write(rb->buffer + (skip + rb->el_len), rb->head - skip);
+        }
+    }
+}
+
+void rb_move(struct ring_buffer *rb, void (*write)(const void *, size_t)) {
+    rb_dump(rb, write, 0);
+    rb->head = 0;
+    rb->tail = 0;
+    rb->full = false;
+}
+
+void rb_peek(struct ring_buffer *rb, void *buf) {
+    if (rb_len(rb) == 0) {
+        return;
+    }
+
+    memcpy(buf, rb->buffer + rb->tail * rb->el_len, rb->el_len);
+}
+
+void rb_pop(struct ring_buffer *rb, void *buf) {
+    if (rb_len(rb) == 0) {
+        return;
+    }
+
+    memcpy(buf, rb->buffer + rb->tail * rb->el_len, rb->el_len);
+    rb->tail++;
+    if (rb->tail >= rb->size) {
+        rb->tail = 0;
+    }
+}
+
+size_t rb_get(struct ring_buffer *rb, void *data, size_t length) {
+    size_t count = 0;
+    while ((length > 0) && (rb_len(rb) > 0)) {
+        rb_pop(rb, data + count * rb->el_len);
+        count++;
+        length--;
+    }
+    return count;
+}

src/sequence.c

@@ -56,6 +56,10 @@ uint32_t sequence_get_bpm(void) {
     return 60000 / (ms_per_beat * beats);
 }
 
+void sequence_set_ms(uint32_t new_ms) {
+    ms_per_beat = new_ms;
+}
+
 uint32_t sequence_get_ms(void) {
     return ms_per_beat;
 }

src/ui.c

@@ -26,16 +26,60 @@
 #include "lcd.h"
 #include "led.h"
 #include "sequence.h"
+#include "usb.h"
+#include "usb_midi.h"
 #include "ui.h"
 
 #define BAT_FETCH_MS 66
 
+enum ui_settings {
+    SETTING_MODE = 0,
+
+    // loop station
+    SETTING_SPEED,
+
+    // drum machine
+    SETTING_BPM,
+    SETTING_BANK,
+    SETTING_LENGTH,
+
+    // midi
+    SETTING_CH_RX,
+    SETTING_CH_TX,
+
+    SETTING_NUM_MODES
+};
+
+static bool allowed_settings[MACHINE_NUM_MODES][SETTING_NUM_MODES] = {
+    // MODE_LOOPSTATION
+    {
+        true, true,
+        false, false, false,
+        false, false,
+    },
+
+    // MODE_DRUMMACHINE
+    {
+        true, false,
+        true, true, true,
+        false, false,
+    },
+
+    // MODE_MIDI
+    {
+        true, false,
+        false, false, false,
+        true, true,
+    },
+};
+
 static bool rec_held_down = false;
-static enum ui_modes ui_mode = 0;
+static enum ui_settings ui_setting = 0;
 static enum machine_modes machine_mode = 0;
 static uint32_t last_bat_fetch = 0;
 static float last_voltage = 0.0f;
 static float last_percentage = 0.0f;
+static uint8_t midi_rx = 0, midi_tx = 0;
 
 enum machine_modes ui_get_machinemode(void) {
     return machine_mode;
@@ -46,19 +90,20 @@ static void ui_redraw(void) {
     char val[64] = {0};
     char bat[64] = {0};
 
-    switch (ui_mode) {
-        case UI_BPM: {
+    switch (ui_setting) {
+        case SETTING_BPM: {
             snprintf(mode, sizeof(mode) - 1, "BPM:");
             snprintf(val, sizeof(val) - 1, "%"PRIu32, sequence_get_bpm());
             break;
         }
 
-        case UI_MODE: {
+        case SETTING_MODE: {
             if ((machine_mode == MODE_LOOPSTATION) && (sequence_get_ms() != 0)) {
                 snprintf(mode, sizeof(mode) - 1, "Mode: %"PRIu32"ms", sequence_get_ms());
-            }else {
+            } else {
                 snprintf(mode, sizeof(mode) - 1, "Mode:");
             }
+
             switch (machine_mode) {
                 case MODE_LOOPSTATION: {
                     snprintf(val, sizeof(val) - 1, "Loop");
@@ -70,6 +115,11 @@ static void ui_redraw(void) {
                     break;
                 }
 
+                case MODE_MIDI: {
+                    snprintf(val, sizeof(val) - 1, "MIDI");
+                    break;
+                }
+
                 default: {
                     printf("%s: invalid machine mode: %d\n", __func__, machine_mode);
                     machine_mode = 0;
@@ -77,24 +127,43 @@ static void ui_redraw(void) {
                     return;
                 }
             }
+
             break;
         }
 
-        case UI_LENGTH: {
+        case SETTING_LENGTH: {
             snprintf(mode, sizeof(mode) - 1, "Length:");
             snprintf(val, sizeof(val) - 1, "%"PRIu32, sequence_get_beats());
             break;
         }
 
-        case UI_BANK: {
+        case SETTING_BANK: {
             snprintf(mode, sizeof(mode) - 1, "Bank:");
             snprintf(val, sizeof(val) - 1, "%"PRIu32, sequence_get_bank());
             break;
         }
 
+        case SETTING_SPEED: {
+            snprintf(mode, sizeof(mode) - 1, "Speed:");
+            snprintf(val, sizeof(val) - 1, "%"PRIu32, sequence_get_ms());
+            break;
+        }
+
+        case SETTING_CH_RX: {
+            snprintf(mode, sizeof(mode) - 1, "Rx-Ch:");
+            snprintf(val, sizeof(val) - 1, "%"PRIu8, midi_rx + 1);
+            break;
+        }
+
+        case SETTING_CH_TX: {
+            snprintf(mode, sizeof(mode) - 1, "Tx-Ch:");
+            snprintf(val, sizeof(val) - 1, "%"PRIu8, midi_tx + 1);
+            break;
+        }
+
         default: {
-            printf("%s: invalid mode: %d\n", __func__, ui_mode);
-            ui_mode = 0;
+            printf("%s: invalid setting: %d\n", __func__, ui_setting);
+            ui_setting = 0;
             ui_redraw();
             return;
         }
@@ -166,16 +235,20 @@ static void ui_buttons_drummachine(enum buttons btn, bool val) {
     }
 }
 
+static void ui_buttons_midi(enum buttons btn, bool val) {
+    // TODO
+    (void)btn;
+    (void)val;
+}
+
 static void ui_buttons(enum buttons btn, bool val) {
     switch (btn) {
         case BTN_CLICK: {
             if (val) {
-                ui_mode = (ui_mode + 1) % UI_NUM_MODES;
-
-                // allow other ui modes only in drumkit mode
-                if (machine_mode == MODE_LOOPSTATION) {
-                    ui_mode = 0;
-                }
+                // only allow settings for this mode
+                do {
+                    ui_setting = (ui_setting + 1) % SETTING_NUM_MODES;
+                } while (!allowed_settings[machine_mode][ui_setting]);
 
                 ui_redraw();
             }
@@ -194,6 +267,11 @@ static void ui_buttons(enum buttons btn, bool val) {
                     break;
                 }
 
+                case MODE_MIDI: {
+                    ui_buttons_midi(btn, val);
+                    break;
+                }
+
                 default: {
                     printf("%s: invalid mode: %d\n", __func__, machine_mode);
                     machine_mode = 0;
@@ -211,14 +289,15 @@ void ui_encoder(int32_t val) {
         return;
     }
 
-    switch (ui_mode) {
-        case UI_BPM: {
+    switch (ui_setting) {
+        case SETTING_BPM: {
             sequence_set_bpm(sequence_get_bpm() + val);
             break;
         }
 
-        case UI_MODE: {
+        case SETTING_MODE: {
             int32_t tmp = machine_mode + val;
+
             while (tmp < 0) {
                 tmp += MACHINE_NUM_MODES;
             }
@@ -226,6 +305,11 @@ void ui_encoder(int32_t val) {
                 tmp -= MACHINE_NUM_MODES;
             }
 
+            // midi only when connected to pc
+            if ((tmp == MODE_MIDI) && !usb_is_connected()) {
+                tmp = (tmp + 1) % MACHINE_NUM_MODES;
+            }
+
             enum machine_modes prev_mode = machine_mode;
             machine_mode = tmp;
 
@@ -240,28 +324,47 @@ void ui_encoder(int32_t val) {
                     led_set(i, false);
                 }
 
-                // enable static LEDs in loopstation mode
                 if (machine_mode == MODE_LOOPSTATION) {
+                    sequence_set_beats(MAX_BEATS);
+
+                    // enable static LEDs in loopstation mode
                     led_set(NUM_CHANNELS, true);
                     led_set(NUM_CHANNELS + 4, true);
+                } else if (machine_mode == MODE_DRUMMACHINE) {
+                    sequence_set_beats(LED_COUNT);
                 }
             }
             break;
         }
 
-        case UI_LENGTH: {
+        case SETTING_LENGTH: {
             sequence_set_beats(sequence_get_beats() + val);
             break;
         }
 
-        case UI_BANK: {
+        case SETTING_BANK: {
             sequence_set_bank(sequence_get_bank() + val);
             break;
         }
 
+        case SETTING_SPEED: {
+            sequence_set_ms(sequence_get_ms() + val);
+            break;
+        }
+
+        case SETTING_CH_RX: {
+            midi_rx = (uint8_t)(midi_rx + val) % MIDI_MAX_CH;
+            break;
+        }
+
+        case SETTING_CH_TX: {
+            midi_tx = (uint8_t)(midi_tx + val) % MIDI_MAX_CH;
+            break;
+        }
+
         default: {
-            printf("%s: invalid mode: %d\n", __func__, ui_mode);
-            ui_mode = 0;
+            printf("%s: invalid setting: %d\n", __func__, ui_setting);
+            ui_setting = 0;
             ui_encoder(val);
             return;
         }
@@ -270,6 +373,21 @@ void ui_encoder(int32_t val) {
     ui_redraw();
 }
 
+void ui_midi_set(uint8_t channel, uint8_t note, uint8_t velocity) {
+    if (machine_mode != MODE_MIDI) {
+        return;
+    }
+
+    if (channel != midi_rx) {
+        return;
+    }
+
+    note = note % NUM_CHANNELS;
+    if (velocity > 0) {
+        sequence_handle_button_loopstation(BTN_A + note, false);
+    }
+}
+
 void ui_init(void) {
     buttons_callback(ui_buttons);
 

src/usb.c

@@ -0,0 +1,80 @@
+/*
+ * Extended from TinyUSB example code.
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "bsp/board.h"
+#include "tusb.h"
+
+#include "log.h"
+#include "usb_descriptors.h"
+#include "usb_midi.h"
+#include "usb.h"
+
+static bool usb_connected = false;
+
+void usb_init(void) {
+    usb_descriptor_init_id();
+
+    board_init();
+    tusb_init();
+}
+
+void usb_run(void) {
+    tud_task();
+    usb_midi_run();
+}
+
+// Invoked when device is mounted
+void tud_mount_cb(void) {
+    debug("device mounted");
+    usb_connected = true;
+}
+
+// Invoked when device is unmounted
+void tud_umount_cb(void) {
+    debug("device unmounted");
+    usb_connected = false;
+}
+
+// Invoked when usb bus is suspended
+// remote_wakeup_en : if host allow us  to perform remote wakeup
+// Within 7ms, device must draw an average of current less than 2.5 mA from bus
+void tud_suspend_cb(bool remote_wakeup_en) {
+    debug("device suspended wakeup=%d", remote_wakeup_en);
+    usb_connected = false;
+}
+
+// Invoked when usb bus is resumed
+void tud_resume_cb(void) {
+    debug("device resumed");
+    usb_connected = tud_mounted();
+}
+
+bool usb_is_connected(void) {
+    return usb_connected;
+}

src/usb_cdc.c

@@ -0,0 +1,117 @@
+/*
+ * Extended from TinyUSB example code.
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "bsp/board.h"
+#include "tusb.h"
+
+#include "console.h"
+#include "log.h"
+#include "main.h"
+#include "usb_descriptors.h"
+#include "usb_cdc.h"
+
+#define ENTER_BOOTLOADER_MAGIC 0x18
+#define DISABLE_CDC_DTR_CHECK
+
+static bool reroute_cdc_debug = false;
+
+void usb_cdc_write(const void *buf, size_t count) {
+#ifndef DISABLE_CDC_DTR_CHECK
+    if (!tud_cdc_connected()) {
+        return;
+    }
+#endif // DISABLE_CDC_DTR_CHECK
+
+    // implemented similar to Pico SDK stdio usb
+    uint32_t len = 0;
+    while (len < count) {
+        uint32_t n = count - len;
+        uint32_t available = tud_cdc_write_available();
+
+        // only write as much as possible
+        if (n > available) {
+            n = available;
+        }
+
+        len += tud_cdc_write(buf + len, n);
+
+        // run tud_task to actually move stuff from FIFO
+        tud_task();
+        tud_cdc_write_flush();
+    }
+}
+
+void usb_cdc_set_reroute(bool reroute) {
+    reroute_cdc_debug = reroute;
+}
+
+static void cdc_task(void) {
+    const uint32_t cdc_buf_len = 64;
+
+    if (tud_cdc_available()) {
+        char buf[cdc_buf_len + 1];
+        uint32_t count = tud_cdc_read(buf, cdc_buf_len);
+
+        if ((count >= 1) && (buf[0] == ENTER_BOOTLOADER_MAGIC)) {
+            reset_to_bootloader();
+        } else if (reroute_cdc_debug) {
+            debug_handle_input((const uint8_t *)buf, count);
+        } else {
+            cnsl_handle_input((const uint8_t *)buf, count);
+        }
+    }
+}
+
+// invoked when cdc when line state changed e.g connected/disconnected
+void tud_cdc_line_state_cb(uint8_t itf, bool dtr, bool rts) {
+    (void) itf;
+    (void) rts;
+
+    static bool last_dtr = false;
+
+    if (dtr && !last_dtr) {
+        // clear left-over console input
+        cnsl_init();
+
+        // show past history
+        log_dump_to_usb();
+
+        debug("terminal connected");
+    } else if (!dtr && last_dtr) {
+        debug("terminal disconnected");
+    }
+
+    last_dtr = dtr;
+}
+
+// invoked when CDC interface received data from host
+void tud_cdc_rx_cb(uint8_t itf) {
+    (void) itf;
+    cdc_task();
+}

src/usb_descriptors.c

@@ -0,0 +1,236 @@
+/*
+ * Extended from TinyUSB example code.
+ *
+ * Copyright (c) 2022 - 2024 Thomas Buck (thomas@xythobuz.de)
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "tusb.h"
+
+#include "usb_descriptors.h"
+
+#ifndef PICOWOTA
+
+/*
+ * A combination of interfaces must have a unique product id,
+ * since PC will save device driver after the first plug.
+ * Same VID/PID with different interface e.g MSC (first),
+ * then CDC (later) will possibly cause system error on PC.
+ *
+ * Auto ProductID layout's Bitmap:
+ *   [MSB]         HID | MSC | CDC          [LSB]
+ */
+#define _PID_MAP(itf, n) ((CFG_TUD_##itf) << (n))
+#define USB_PID (0x2300 | _PID_MAP(CDC, 0) | _PID_MAP(MSC, 1) \
+    | _PID_MAP(HID, 2) | _PID_MAP(MIDI, 3) | _PID_MAP(VENDOR, 4) )
+
+#define USB_VID   0xCafe
+#define USB_BCD   0x0200
+
+//--------------------------------------------------------------------+
+// Device Descriptors
+//--------------------------------------------------------------------+
+
+tusb_desc_device_t const desc_device =
+{
+    .bLength            = sizeof(tusb_desc_device_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE,
+    .bcdUSB             = USB_BCD,
+
+    /*
+     * Use Interface Association Descriptor (IAD) for CDC
+     * As required by USB Specs IAD's subclass must be common class (2)
+     * and protocol must be IAD (1)
+     */
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+
+    .idVendor           = USB_VID,
+    .idProduct          = USB_PID,
+    .bcdDevice          = 0x0100,
+
+    .iManufacturer      = 0x01,
+    .iProduct           = 0x02,
+    .iSerialNumber      = 0x03,
+
+    .bNumConfigurations = 0x01
+};
+
+// Invoked when received GET DEVICE DESCRIPTOR
+// Application return pointer to descriptor
+uint8_t const * tud_descriptor_device_cb(void) {
+    return (uint8_t const *) &desc_device;
+}
+
+//--------------------------------------------------------------------+
+// Configuration Descriptor
+//--------------------------------------------------------------------+
+
+enum {
+    ITF_NUM_CDC = 0,
+    ITF_NUM_CDC_DATA,
+    ITF_NUM_MIDI,
+    ITF_NUM_MIDI_STREAMING,
+    ITF_NUM_TOTAL
+};
+
+#define  CONFIG_TOTAL_LEN  (TUD_CONFIG_DESC_LEN + TUD_CDC_DESC_LEN + TUD_MIDI_DESC_LEN)
+
+#define EPNUM_CDC_NOTIF 0x82
+#define EPNUM_CDC_OUT   0x02
+#define EPNUM_CDC_IN    0x83
+#define EPNUM_MIDI_OUT   0x03
+#define EPNUM_MIDI_IN    0x84
+
+uint8_t const desc_configuration[] = {
+    // Config number, interface count, string index, total length, attribute, power in mA
+    TUD_CONFIG_DESCRIPTOR(1, ITF_NUM_TOTAL, 0, CONFIG_TOTAL_LEN, TUSB_DESC_CONFIG_ATT_REMOTE_WAKEUP, 100),
+
+    // Interface number, string index, EP notification address and size, EP data address (out, in) and size.
+    TUD_CDC_DESCRIPTOR(ITF_NUM_CDC, 4, EPNUM_CDC_NOTIF, 8, EPNUM_CDC_OUT, EPNUM_CDC_IN, CFG_TUD_CDC_EP_BUFSIZE),
+
+    // Interface number, string index, EP Out & EP In address, EP size
+    TUD_MIDI_DESCRIPTOR(ITF_NUM_MIDI, 5, EPNUM_MIDI_OUT, EPNUM_MIDI_IN, CFG_TUD_CDC_MIDI_BUFSIZE)
+};
+
+#if TUD_OPT_HIGH_SPEED
+// Per USB specs: high speed capable device must report device_qualifier and other_speed_configuration
+
+// other speed configuration
+uint8_t desc_other_speed_config[CONFIG_TOTAL_LEN];
+
+// device qualifier is mostly similar to device descriptor since we don't change configuration based on speed
+tusb_desc_device_qualifier_t const desc_device_qualifier = {
+    .bLength            = sizeof(tusb_desc_device_qualifier_t),
+    .bDescriptorType    = TUSB_DESC_DEVICE_QUALIFIER,
+    .bcdUSB             = USB_BCD,
+
+    .bDeviceClass       = TUSB_CLASS_MISC,
+    .bDeviceSubClass    = MISC_SUBCLASS_COMMON,
+    .bDeviceProtocol    = MISC_PROTOCOL_IAD,
+
+    .bMaxPacketSize0    = CFG_TUD_ENDPOINT0_SIZE,
+    .bNumConfigurations = 0x01,
+    .bReserved          = 0x00
+};
+
+// Invoked when received GET DEVICE QUALIFIER DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete.
+// device_qualifier descriptor describes information about a high-speed capable device that would
+// change if the device were operating at the other speed. If not highspeed capable stall this request.
+uint8_t const* tud_descriptor_device_qualifier_cb(void) {
+    return (uint8_t const*) &desc_device_qualifier;
+}
+
+// Invoked when received GET OTHER SEED CONFIGURATION DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+// Configuration descriptor in the other speed e.g if high speed then this is for full speed and vice versa
+uint8_t const* tud_descriptor_other_speed_configuration_cb(uint8_t index) {
+    (void) index; // for multiple configurations
+
+    // other speed config is basically configuration with type = OHER_SPEED_CONFIG
+    memcpy(desc_other_speed_config, desc_configuration, CONFIG_TOTAL_LEN);
+    desc_other_speed_config[1] = TUSB_DESC_OTHER_SPEED_CONFIG;
+
+    // this example use the same configuration for both high and full speed mode
+    return desc_other_speed_config;
+}
+
+#endif // highspeed
+
+// Invoked when received GET CONFIGURATION DESCRIPTOR
+// Application return pointer to descriptor
+// Descriptor contents must exist long enough for transfer to complete
+uint8_t const * tud_descriptor_configuration_cb(uint8_t index) {
+    (void) index; // for multiple configurations
+
+    // This example use the same configuration for both high and full speed mode
+    return desc_configuration;
+}
+
+#endif // PICOWOTA
+
+//--------------------------------------------------------------------+
+// String Descriptors
+//--------------------------------------------------------------------+
+
+char string_pico_serial[2 * PICO_UNIQUE_BOARD_ID_SIZE_BYTES + 1];
+
+void usb_descriptor_init_id(void) {
+    pico_get_unique_board_id_string(string_pico_serial, sizeof(string_pico_serial));
+}
+
+#ifndef PICOWOTA
+
+// array of pointer to string descriptors
+char const* string_desc_arr [] = {
+    (const char[]) { 0x09, 0x04 }, // 0: is supported language is English (0x0409)
+    "xythobuz",                    // 1: Manufacturer
+    "LARS",                        // 2: Product
+    string_pico_serial,            // 3: Serials, should use chip ID
+    "Debug Serial",                // 4: CDC Interface
+    "LARS MIDI",                   // 5: MIDI Interface
+};
+
+static uint16_t _desc_str[32];
+
+// Invoked when received GET STRING DESCRIPTOR request
+// Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
+uint16_t const* tud_descriptor_string_cb(uint8_t index, uint16_t langid) {
+    (void) langid;
+
+    uint8_t chr_count;
+
+    if ( index == 0) {
+        memcpy(&_desc_str[1], string_desc_arr[0], 2);
+        chr_count = 1;
+    } else {
+        // Note: the 0xEE index string is a Microsoft OS 1.0 Descriptors.
+        // https://docs.microsoft.com/en-us/windows-hardware/drivers/usbcon/microsoft-defined-usb-descriptors
+
+        if ( !(index < sizeof(string_desc_arr)/sizeof(string_desc_arr[0])) ) return NULL;
+
+        const char* str = string_desc_arr[index];
+
+        // Cap at max char
+        chr_count = strlen(str);
+        if ( chr_count > 31 ) chr_count = 31;
+
+        // Convert ASCII string into UTF-16
+        for(uint8_t i=0; i<chr_count; i++) {
+            _desc_str[1+i] = str[i];
+        }
+    }
+
+    // first byte is length (including header), second byte is string type
+    _desc_str[0] = (TUSB_DESC_STRING << 8 ) | (2*chr_count + 2);
+
+    return _desc_str;
+}
+
+#endif // PICOWOTA

src/usb_midi.c

@@ -0,0 +1,69 @@
+/*
+ * Extended from TinyUSB example code.
+ *
+ * Copyright (c) 2022 - 2023 Thomas Buck (thomas@xythobuz.de)
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2019 Ha Thach (tinyusb.org)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ */
+
+#include "bsp/board.h"
+#include "tusb.h"
+
+#include "log.h"
+#include "ui.h"
+#include "usb_midi.h"
+
+#define MIDI_CABLE_NUM 0 // MIDI jack associated with USB endpoint
+
+#define MIDI_NOTE_OFF 0x80
+#define MIDI_NOTE_ON 0x90
+
+void usb_midi_tx(uint8_t channel, uint8_t note, uint8_t velocity) {
+    uint8_t packet[3] = {
+        ((velocity == 0) ? MIDI_NOTE_OFF : MIDI_NOTE_ON) | channel,
+        note, velocity,
+    };
+
+    tud_midi_stream_write(MIDI_CABLE_NUM, packet, sizeof(packet));
+}
+
+void usb_midi_run(void) {
+    while (tud_midi_available()) {
+        uint8_t packet[4];
+        tud_midi_packet_read(packet);
+        //debug("rx: %02X %02X %02X %02X", packet[0], packet[1], packet[2], packet[3]);
+
+        uint8_t type = packet[1] & 0xF0;
+        uint8_t channel = packet[1] & 0x0F;
+        uint8_t note = packet[2];
+        uint8_t velocity = packet[3];
+        //debug("rx: type=%02X channel=%d note=%d velocity=%d", type, channel, note, velocity);
+
+        if (type == MIDI_NOTE_OFF) {
+            ui_midi_set(channel, note, 0);
+        } else if (type == MIDI_NOTE_ON) {
+            ui_midi_set(channel, note, (velocity == 0) ? 127 : velocity);
+        }
+    }
+}