initial commit

.clangd

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+CompileFlags:
+  CompilationDatabase: build/

.gitignore

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+build

.gitmodules

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+[submodule "pico-sdk"]
+	path = pico-sdk
+	url = https://github.com/raspberrypi/pico-sdk
+[submodule "pico-ssd1306"]
+	path = pico-ssd1306
+	url = https://github.com/daschr/pico-ssd1306

CMakeLists.txt

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+# ----------------------------------------------------------------------------
+# 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/>.
+# ----------------------------------------------------------------------------
+
+cmake_minimum_required(VERSION 3.13)
+
+# initialize pico-sdk from submodule
+include(pico-sdk/pico_sdk_init.cmake)
+
+project(gadget C CXX)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+
+# initialize the Raspberry Pi Pico SDK
+pico_sdk_init()
+
+add_executable(drumkit)
+
+target_sources(drumkit PUBLIC
+    src/main.c
+    src/lcd.c
+    src/buttons.c
+    src/encoder.c
+    src/sequence.c
+    src/led.c
+
+    pico-ssd1306/ssd1306.c
+)
+
+# external dependency include directories
+target_include_directories(drumkit PUBLIC ${CMAKE_CURRENT_LIST_DIR}/include)
+target_include_directories(drumkit PUBLIC ${CMAKE_CURRENT_LIST_DIR}/pico-ssd1306)
+
+# enable generous warnings
+target_compile_options(drumkit PUBLIC
+    -Wall
+    -Wextra
+    -Werror
+    -Wshadow
+)
+
+# suppress some warnings for borked 3rd party files in Pico SDK
+set_source_files_properties(pico-sdk/lib/btstack/src/ble/sm.c PROPERTIES COMPILE_FLAGS -Wno-unused-parameter)
+set_source_files_properties(pico-sdk/lib/btstack/src/btstack_hid_parser.c PROPERTIES COMPILE_FLAGS -Wno-maybe-uninitialized)
+set_source_files_properties(pico-sdk/src/rp2_common/pico_cyw43_driver/cyw43_driver.c PROPERTIES COMPILE_FLAGS -Wno-unused-parameter)
+set_source_files_properties(pico-sdk/lib/btstack/src/classic/avdtp_util.c PROPERTIES COMPILE_FLAGS -Wno-unused-parameter)
+set_source_files_properties(pico-sdk/lib/btstack/src/classic/goep_client.c PROPERTIES COMPILE_FLAGS -Wno-unused-parameter)
+set_source_files_properties(pico-sdk/lib/btstack/src/classic/goep_server.c PROPERTIES COMPILE_FLAGS -Wno-unused-parameter)
+set_source_files_properties(pico-sdk/src/rp2_common/hardware_flash/flash.c PROPERTIES COMPILE_FLAGS -Wno-shadow)
+
+# pull in common dependencies
+target_link_libraries(drumkit
+    pico_stdlib
+    hardware_i2c
+    hardware_adc
+    hardware_gpio
+    hardware_pwm
+)
+
+# enable usb output, disable uart output
+pico_enable_stdio_usb(drumkit 1)
+pico_enable_stdio_uart(drumkit 0)
+
+# fix for Errata RP2040-E5 (the fix requires use of GPIO 15)
+target_compile_definitions(drumkit PUBLIC PICO_RP2040_USB_DEVICE_ENUMERATION_FIX=1)
+
+pico_add_extra_outputs(drumkit)

README.md

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+# Drumkit
+
+## Hardware Connections
+
+    Pin 1    GP0    I2C SDA
+    Pin 2    GP1    I2C SCL
+
+    Pin 4    GP2    Output Channel A
+    Pin 5    GP3    Output Channel B
+    Pin 6    GP4    Output Channel C
+
+    Pin 7    GP5    Button 1
+    Pin 9    GP6    Button 2
+    Pin 10   GP7    Button 3
+    Pin 11   GP8    Button 4
+
+    Pin 12   GP9    Encoder A
+    Pin 14   GP10   Encoder B
+    Pin 15   GP11   Encoder Click
+
+    Pin 16   GP12   LED 1
+    Pin 17   GP13   LED 2
+    Pin 19   GP14   LED 3
+    Pin 20   GP15   LED 4

include/buttons.h

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+/*
+ * buttons.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 __BUTTONS_H__
+#define __BUTTONS_H__
+
+#include <stdbool.h>
+
+enum buttons {
+    BTN_A = 0,
+    BTN_B,
+    BTN_C,
+    BTN_REC,
+    BTN_CLICK,
+    NUM_BTNS // count
+};
+
+void buttons_init(void);
+void buttons_callback(void (*fp)(enum buttons, bool));
+void buttons_run(void);
+
+#endif // __BUTTONS_H__
+

include/encoder.h

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+/*
+ * encoder.h
+ *
+ * Based on https://github.com/mathertel/RotaryEncoder/blob/master/src/RotaryEncoder.cpp
+ */
+
+#ifndef __ENCODER_H__
+#define __ENCODER_H__
+
+void encoder_init(void);
+int32_t encoder_pos(void);
+void encoder_run(void);
+
+#endif // __ENCODER_H__
+

include/lcd.h

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+/*
+ * lcd.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 __LCD_H__
+#define __LCD_H__
+
+void lcd_init(void);
+
+#endif // __LCD_H__

include/led.h

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+/*
+ * led.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 __LED_H__
+#define __LED_H__
+
+void led_init(void);
+void led_set(uint32_t i, bool v);
+
+#endif // __LED_H__

include/main.h

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+/*
+ * main.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 __MAIN_H__
+#define __MAIN_H__
+
+
+
+#endif // __MAIN_H__

include/sequence.h

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+/*
+ * sequence.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 __SEQUENCE_H__
+#define __SEQUENCE_H__
+
+void sequence_init(void);
+void sequence_set_bpm(uint32_t new_bpm);
+void sequence_set_beats(uint32_t new_beats);
+void sequence_set(uint32_t beat, bool value);
+void sequence_run(void);
+
+#endif // __SEQUENCE_H__

pico-sdk

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+Subproject commit 6a7db34ff63345a7badec79ebea3aaef1712f374

pico-ssd1306

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+Subproject commit 8467f5b06ebd7bfa7b53e4ebc83dfdc6f396e4eb

src/buttons.c

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+/*
+ * buttons.c
+ *
+ * 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/>.
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+
+#include "buttons.h"
+
+#define DEBOUNCE_DELAY_MS 50
+
+static const uint gpio_num[NUM_BTNS] = {
+    5, // BTN_A
+    6, // BTN_B
+    7, // BTN_C
+    8, // BTN_REC
+    11, // BTN_CLICK
+};
+
+struct button_state {
+    uint32_t last_time;
+    bool current_state, last_state;
+};
+
+static struct button_state buttons[NUM_BTNS];
+static void (*callback)(enum buttons, bool) = NULL;
+
+void buttons_init(void) {
+    for (uint i = 0; i < NUM_BTNS; i++) {
+        gpio_init(gpio_num[i]);
+        gpio_set_dir(gpio_num[i], GPIO_IN);
+        gpio_pull_up(gpio_num[i]);
+
+        buttons[i].last_time = 0;
+        buttons[i].current_state = false;
+        buttons[i].last_state = false;
+    }
+}
+
+void buttons_callback(void (*fp)(enum buttons, bool)) {
+    callback = fp;
+}
+
+void buttons_run(void) {
+    for (uint i = 0; i < NUM_BTNS; i++) {
+        bool state = !gpio_get(gpio_num[i]);
+        uint32_t now = to_ms_since_boot(get_absolute_time());
+
+        if (state != buttons[i].last_state) {
+            buttons[i].last_time = now;
+        }
+
+        if ((now - buttons[i].last_time) > DEBOUNCE_DELAY_MS) {
+            if (state != buttons[i].current_state) {
+                printf("btn %d now %s\n", i, state ? "pressed" : "released");
+
+                buttons[i].current_state = state;
+                if (callback) {
+                    callback(i, state);
+                }
+            }
+        }
+
+        buttons[i].last_state = state;
+    }
+}

src/encoder.c

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+/*
+ * encoder.c
+ *
+ * Based on https://github.com/mathertel/RotaryEncoder/blob/master/src/RotaryEncoder.cpp
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+
+#include "encoder.h"
+
+#define LATCH0 0
+#define LATCH3 3
+
+#define FOUR3 1 // 4 steps, Latch at position 3 only (compatible to older versions)
+#define FOUR0 2 // 4 steps, Latch at position 0 (reverse wirings)
+#define TWO03 3 // 2 steps, Latch at position 0 and 3
+
+#define ENCODER_MODE TWO03
+
+static const uint gpio_num[2] = {
+    9, 10
+};
+
+static const int8_t KNOBDIR[] = {
+    0, -1, 1, 0,
+    1, 0, 0, -1,
+    -1, 0, 0, 1,
+    0, 1, -1, 0
+};
+
+static int8_t oldState;
+static int32_t position;
+static int32_t positionExt;
+static int32_t positionExtPrev;
+
+void encoder_init(void) {
+    for (uint i = 0; i < 2; i++) {
+        gpio_init(gpio_num[i]);
+        gpio_set_dir(gpio_num[i], GPIO_IN);
+        gpio_pull_up(gpio_num[i]);
+    }
+
+    oldState = gpio_get(gpio_num[0]) | (gpio_get(gpio_num[1]) << 1);
+    position = 0;
+    positionExt = 0;
+    positionExtPrev = 0;
+}
+
+int32_t encoder_pos(void)
+{
+    return positionExt;
+}
+
+void encoder_run(void) {
+    int8_t thisState = gpio_get(gpio_num[0]) | (gpio_get(gpio_num[1]) << 1);
+
+    if (oldState != thisState) {
+        position += KNOBDIR[thisState | (oldState << 2)];
+        oldState = thisState;
+
+        switch (ENCODER_MODE) {
+        case FOUR3:
+            if (thisState == LATCH3) {
+                // The hardware has 4 steps with a latch on the input state 3
+                positionExt = position >> 2;
+            }
+            break;
+
+        case FOUR0:
+            if (thisState == LATCH0) {
+                // The hardware has 4 steps with a latch on the input state 0
+                positionExt = position >> 2;
+            }
+            break;
+
+        case TWO03:
+            if ((thisState == LATCH0) || (thisState == LATCH3)) {
+                // The hardware has 2 steps with a latch on the input state 0 and 3
+                positionExt = position >> 1;
+            }
+            break;
+        }
+    }
+}

src/lcd.c

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+/*
+ * lcd.c
+ *
+ * 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/>.
+ */
+
+#include <stdio.h>
+#include <stdint.h>
+#include <string.h>
+#include "pico/stdlib.h"
+#include "hardware/i2c.h"
+
+#include "ssd1306.h"
+#include "lcd.h"
+
+static ssd1306_t disp;
+
+void lcd_init(void) {
+    i2c_init(i2c1, 400000);
+    gpio_set_function(0, GPIO_FUNC_I2C);
+    gpio_set_function(1, GPIO_FUNC_I2C);
+    gpio_pull_up(0);
+    gpio_pull_up(1);
+
+    disp.external_vcc = false;
+    ssd1306_init(&disp, 128, 64, 0x3C, i2c1);
+}

src/led.c

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+/*
+ * led.c
+ *
+ * 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/>.
+ */
+
+#include "pico/stdlib.h"
+
+#include "led.h"
+
+#define LED_COUNT 4
+
+static const uint gpio_num[LED_COUNT] = {
+    12, 13, 14, 15,
+};
+
+void led_init(void) {
+    for (uint i = 0; i < LED_COUNT; i++) {
+        gpio_init(gpio_num[i]);
+        gpio_set_dir(gpio_num[i], GPIO_IN);
+    }
+}
+
+void led_set(uint32_t i, bool v) {
+    i %= LED_COUNT;
+    gpio_put(i, v);
+}

src/main.c

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+/*
+ * main.c
+ *
+ * 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/>.
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/watchdog.h"
+
+#include "buttons.h"
+#include "encoder.h"
+#include "lcd.h"
+#include "sequence.h"
+#include "main.h"
+
+#define WATCHDOG_PERIOD_MS 100
+
+int main(void) {
+    watchdog_enable(WATCHDOG_PERIOD_MS, 1);
+    stdio_init_all();
+    buttons_init();
+    lcd_init();
+    sequence_init();
+    printf("init done\n");
+
+    while (1) {
+        watchdog_update();
+        buttons_run();
+        encoder_run();
+        sequence_run();
+    }
+
+    return 0;
+}

src/sequence.c

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+/*
+ * sequence.c
+ *
+ * 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/>.
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+
+#include "led.h"
+#include "sequence.h"
+
+#define MAX_BEATS 32
+
+static uint32_t ms_per_beat = 500;
+static uint32_t beats = 16;
+static uint32_t last_t = 0;
+static uint32_t last_i = 0;
+
+static bool sequence[MAX_BEATS] = {0};
+
+void sequence_init(void) {
+    last_t = to_ms_since_boot(get_absolute_time());
+    last_i = 0;
+}
+
+void sequence_set_bpm(uint32_t new_bpm) {
+    ms_per_beat = 60000 / new_bpm;
+}
+
+void sequence_set_beats(uint32_t new_beats) {
+    beats = (new_beats <= MAX_BEATS) ? new_beats : MAX_BEATS;
+}
+
+void sequence_set(uint32_t beat, bool value) {
+    if (beat < MAX_BEATS) {
+        sequence[beat] = value;
+    }
+}
+
+void sequence_run(void) {
+    uint32_t now = to_ms_since_boot(get_absolute_time());
+
+    if ((last_t + ms_per_beat) >= now) {
+        uint32_t i = last_i + 1;
+        if (i >= beats) i = 0;
+
+        led_set(last_i, false);
+        led_set(i, true);
+
+        if (sequence[i]) {
+            // TODO trigger GPIO impulse
+        }
+
+        last_t = now;
+        last_i = i;
+    }
+}