Provide 1:1 examples from original to port and use them tests when building docs.

Makefile

@@ -0,0 +1,14 @@
+BUILD_DIR = tests/build
+
+dist-tests: $(BUILD_DIR)/Makefile
+	@$(MAKE) -C $(BUILD_DIR) examples
+	@echo "All examples compiled successfully."
+
+$(BUILD_DIR)/Makefile: tests/CMakeLists.txt tests/examples/CMakeLists.txt
+	@mkdir -p $(BUILD_DIR)
+	@cd $(BUILD_DIR) && PICO_SDK_PATH=$$HOME/Staging/pico-sdk cmake ..
+
+clean:
+	@rm -rf $(BUILD_DIR)
+
+.PHONY: dist-tests clean

docs

@@ -1 +1 @@
-Subproject commit 7b2e25395d18139a822910b85119a819e6724444
+Subproject commit fe877262d1b3d3283060dcaabe6a576b45ca0f1b

tests/CMakeLists.txt

@@ -0,0 +1,21 @@
+# Standalone build for cs-midi examples — compile-only verification.
+# Invoked via: make dist-tests (from lib/cs-midi/)
+
+set(PICO_BOARD pico2_w)
+
+cmake_minimum_required(VERSION 3.13)
+
+include(pico_sdk_import.cmake)
+
+project(cs_midi_examples C CXX ASM)
+set(CMAKE_C_STANDARD 11)
+set(CMAKE_CXX_STANDARD 17)
+
+pico_sdk_init()
+
+add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/.. ${CMAKE_CURRENT_BINARY_DIR}/cs_midi)
+
+# cs_midi's BTstack sources need btstack_config.h from this directory
+target_include_directories(cs_midi PRIVATE ${CMAKE_CURRENT_LIST_DIR})
+
+add_subdirectory(${CMAKE_CURRENT_LIST_DIR}/examples ${CMAKE_CURRENT_BINARY_DIR}/examples)

tests/btstack_config.h

@@ -0,0 +1,43 @@
+#ifndef _BTSTACK_CONFIG_H
+#define _BTSTACK_CONFIG_H
+
+// BLE
+#define ENABLE_LE_PERIPHERAL
+#define ENABLE_LE_CENTRAL
+#define ENABLE_L2CAP_LE_CREDIT_BASED_FLOW_CONTROL_MODE
+
+#define HCI_OUTGOING_PRE_BUFFER_SIZE 4
+#define HCI_ACL_PAYLOAD_SIZE (1691 + 4)
+#define HCI_ACL_CHUNK_SIZE_ALIGNMENT 4
+
+#define MAX_NR_GATT_CLIENTS 1
+#define MAX_NR_HCI_CONNECTIONS 2
+#define MAX_NR_L2CAP_CHANNELS 4
+#define MAX_NR_L2CAP_SERVICES 3
+#define MAX_NR_SM_LOOKUP_ENTRIES 3
+#define MAX_NR_WHITELIST_ENTRIES 1
+#define MAX_NR_LE_DEVICE_DB_ENTRIES 4
+
+#define MAX_NR_CONTROLLER_ACL_BUFFERS 3
+#define MAX_NR_CONTROLLER_SCO_PACKETS 3
+
+#define ENABLE_HCI_CONTROLLER_TO_HOST_FLOW_CONTROL
+#define HCI_HOST_ACL_PACKET_LEN 1024
+#define HCI_HOST_ACL_PACKET_NUM 3
+#define HCI_HOST_SCO_PACKET_LEN 120
+#define HCI_HOST_SCO_PACKET_NUM 3
+
+#define NVM_NUM_DEVICE_DB_ENTRIES 16
+
+#define MAX_ATT_DB_SIZE 512
+
+#define ENABLE_LOG_INFO
+#define ENABLE_PRINTF_HEXDUMP
+
+#define HAVE_EMBEDDED_TIME_MS
+#define HAVE_ASSERT
+
+#define ENABLE_SOFTWARE_AES128
+#define ENABLE_MICRO_ECC_FOR_LE_SECURE_CONNECTIONS
+
+#endif

tests/examples/CMakeLists.txt

@@ -0,0 +1,70 @@
+# Build each example as a standalone executable to verify compilation.
+# Invoked via: make dist-tests (from lib/cs-midi/)
+
+set(EXAMPLE_SOURCES
+    # Output elements
+    output/note_button.cpp
+    output/cc_button.cpp
+    output/pc_button.cpp
+    output/note_chord_button.cpp
+    output/note_button_latched.cpp
+    output/note_button_latching.cpp
+    output/note_buttons.cpp
+    output/note_button_matrix.cpp
+    output/cc_button_latched.cpp
+    output/cc_button_latching.cpp
+    output/cc_buttons.cpp
+    output/cc_button_matrix.cpp
+    output/cc_potentiometer.cpp
+    output/pb_potentiometer.cpp
+    output/cc_rotary_encoder.cpp
+    output/cc_absolute_encoder.cpp
+    output/pb_absolute_encoder.cpp
+    output/cc_increment_decrement_buttons.cpp
+    output/program_changer.cpp
+    output/cc_potentiometers.cpp
+    output/borrowed_cc_rotary_encoder.cpp
+
+    # Input elements
+    input/note_led.cpp
+    input/note_range_leds.cpp
+    input/cc_value.cpp
+    input/pb_value.cpp
+    input/note_value.cpp
+    input/kp_value.cpp
+    input/cc_led.cpp
+    input/note_range.cpp
+    input/cc_range.cpp
+
+    # Interfaces
+    interfaces/ble_midi.cpp
+    interfaces/midi_pipes.cpp
+
+    # Banks
+    banks/bank_cc_values.cpp
+    banks/transposer.cpp
+    banks/encoder_selector.cpp
+    banks/many_buttons_selector.cpp
+    banks/switch_selector.cpp
+    banks/program_change_selector.cpp
+    banks/bankable_note_led.cpp
+)
+
+foreach(src ${EXAMPLE_SOURCES})
+    get_filename_component(name ${src} NAME_WE)
+    set(target "example_${name}")
+    add_executable(${target} ${src})
+    target_include_directories(${target} PRIVATE ${CMAKE_SOURCE_DIR})
+    target_link_libraries(${target}
+        pico_stdlib
+        pico_cyw43_arch_lwip_threadsafe_background
+        pico_btstack_ble
+        pico_btstack_cyw43
+        hardware_adc
+        cs_midi
+    )
+    set_target_properties(${target} PROPERTIES EXCLUDE_FROM_ALL TRUE)
+    list(APPEND EXAMPLE_TARGETS ${target})
+endforeach()
+
+add_custom_target(examples DEPENDS ${EXAMPLE_TARGETS})

tests/examples/banks/bank_cc_values.cpp

@@ -0,0 +1,51 @@
+// Bank with bankable CC input elements.
+// Demonstrates bank switching with input-side bankable elements.
+// Note: bankable OUTPUT elements (e.g. Bankable::CCPotentiometer) are not yet
+// extracted. This example uses bankable INPUT elements instead.
+// Original concept: examples/5.Banks/Bank/Bank.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+// 4 banks, 2 tracks per bank
+Bank<4> bank(2);
+
+// Selector: two buttons to increment/decrement the active bank
+IncrementDecrementSelector<4> selector {
+    bank,
+    {2, 3},
+    Wrap::Wrap,
+};
+
+// Bankable CC value readers — bank switching changes the CC address.
+// Bank 1: reads CC 16, CC 17
+// Bank 2: reads CC 18, CC 19
+// Bank 3: reads CC 20, CC 21
+// Bank 4: reads CC 22, CC 23
+Bankable::CCValue<4> ccVal1 {
+    {bank, BankType::ChangeAddress},
+    {16, Channel_1},
+};
+Bankable::CCValue<4> ccVal2 {
+    {bank, BankType::ChangeAddress},
+    {17, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t v1 = ccVal1.getValue();
+        uint8_t v2 = ccVal2.getValue();
+        (void)v1;
+        (void)v2;
+        sleep_ms(1);
+    }
+}

tests/examples/banks/bankable_note_led.cpp

@@ -0,0 +1,33 @@
+// Bankable NoteLED — bank-switched LED responds to different notes per bank.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+Bank<4> bank(1);
+
+IncrementDecrementSelector<4> selector {
+    bank,
+    {2, 3},
+    Wrap::Wrap,
+};
+
+Bankable::NoteLED<4> led {
+    {bank, BankType::ChangeAddress},
+    13,
+    {MIDI_Notes::C[4], Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/banks/encoder_selector.cpp

@@ -0,0 +1,35 @@
+// EncoderSelector — bank selection via rotary encoder.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+Bank<4> bank(2);
+
+Bankable::CCValue<4> ccVal {
+    {bank, BankType::ChangeAddress},
+    {16, Channel_1},
+};
+
+EncoderSelector<4> selector {
+    bank,
+    {0, 2},
+    4,
+    Wrap::Wrap,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = ccVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/banks/many_buttons_selector.cpp

@@ -0,0 +1,33 @@
+// ManyButtonsSelector — one button per bank.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+Bank<4> bank(2);
+
+Bankable::CCValue<4> ccVal {
+    {bank, BankType::ChangeAddress},
+    {16, Channel_1},
+};
+
+ManyButtonsSelector<4> selector {
+    bank,
+    {2, 3, 4, 5},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = ccVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/banks/program_change_selector.cpp

@@ -0,0 +1,33 @@
+// ProgramChangeSelector — bank selection via incoming MIDI Program Change.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+Bank<8> bank(1);
+
+Bankable::CCValue<8> ccVal {
+    {bank, BankType::ChangeAddress},
+    {16, Channel_1},
+};
+
+ProgramChangeSelector<8> selector {
+    bank,
+    {Channel_1, Cable_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = ccVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/banks/switch_selector.cpp

@@ -0,0 +1,33 @@
+// SwitchSelector — two-state bank from toggle switch.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+Bank<2> bank(1);
+
+Bankable::CCValue<2> ccVal {
+    {bank, BankType::ChangeAddress},
+    {16, Channel_1},
+};
+
+SwitchSelector selector {
+    bank,
+    5,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = ccVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/banks/transposer.cpp

@@ -0,0 +1,30 @@
+// Transposer — note transposition via buttons.
+// Original: examples/5.Banks/Transposer/Transposer.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+Transposer<-12, +12> transposer;
+
+NoteButton button {5, {MIDI_Notes::C[4], Channel_1}};
+
+IncrementDecrementSelector<25> selector {
+    transposer,
+    {2, 3},
+    Wrap::Clamp,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/input/cc_led.cpp

@@ -0,0 +1,24 @@
+// CCLED — LED responds to incoming CC messages.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCLED led {
+    13,
+    {MIDI_CC::General_Purpose_Controller_1, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/input/cc_range.cpp

@@ -0,0 +1,25 @@
+// CCRange — reads a contiguous range of incoming CC values.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCRange<8> ccRange {{MIDI_CC::General_Purpose_Controller_1, Channel_1}};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        for (uint8_t i = 0; i < 8; i++) {
+            uint8_t val = ccRange.getValue(i);
+            (void)val;
+        }
+        sleep_ms(1);
+    }
+}

tests/examples/input/cc_value.cpp

@@ -0,0 +1,25 @@
+// CCValue — reads incoming CC messages and stores the value.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCValue ccVal {
+    {MIDI_CC::Channel_Volume, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = ccVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/input/kp_value.cpp

@@ -0,0 +1,23 @@
+// KPValue — reads incoming Key Pressure (aftertouch) values.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+KPValue kpVal {{MIDI_Notes::C[4], Channel_1}};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = kpVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/input/note_led.cpp

@@ -0,0 +1,25 @@
+// NoteLED — LED responds to incoming Note On/Off messages.
+// Original: examples/2. MIDI Input/1. LEDs/1.Note-LED/1.Note-LED.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteLED led {
+    13,                            // LED pin
+    {MIDI_Notes::C[4], Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/input/note_range.cpp

@@ -0,0 +1,25 @@
+// NoteRange — reads a contiguous range of incoming Note values.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteRange<4> noteRange {{MIDI_Notes::C[4], Channel_1}};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        for (uint8_t i = 0; i < 4; i++) {
+            uint8_t val = noteRange.getValue(i);
+            (void)val;
+        }
+        sleep_ms(1);
+    }
+}

tests/examples/input/note_range_leds.cpp

@@ -0,0 +1,27 @@
+// NoteRange + LEDs — multiple LEDs respond to a range of incoming notes.
+// Original: examples/2. MIDI Input/1. LEDs/2.Note-Range-LEDs/2.Note-Range-LEDs.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteLED leds[] {
+    {2, {MIDI_Notes::C[4], Channel_1}},
+    {3, {MIDI_Notes::D[4], Channel_1}},
+    {4, {MIDI_Notes::E[4], Channel_1}},
+    {5, {MIDI_Notes::F[4], Channel_1}},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/input/note_value.cpp

@@ -0,0 +1,23 @@
+// NoteValue — reads incoming Note On values.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteValue noteVal {{MIDI_Notes::C[4], Channel_1}};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint8_t val = noteVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/input/pb_value.cpp

@@ -0,0 +1,24 @@
+// PBValue — reads incoming Pitch Bend messages (14-bit).
+// Original: examples/2. MIDI Input/Pitch-Bend-Value/Pitch-Bend-Value.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+PBValue pbVal {Channel_1};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        uint16_t val = pbVal.getValue();
+        (void)val;
+        sleep_ms(1);
+    }
+}

tests/examples/interfaces/ble_midi.cpp

@@ -0,0 +1,24 @@
+// BLE MIDI — basic Bluetooth Low Energy MIDI interface setup.
+// This is the primary interface for cs-midi on pico-sdk.
+// Replaces USBMIDI_Interface from the original Control Surface library.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteButton button {5, {MIDI_Notes::C[4], Channel_1}};
+CCRotaryEncoder enc {{0, 2}, {16, Channel_1}, 1, 4};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/interfaces/midi_pipes.cpp

@@ -0,0 +1,28 @@
+// MIDI Pipes — routing between interfaces.
+// Original: examples/3. MIDI Interfaces/MIDI_Pipes-Routing/MIDI_Pipes-Routing.ino
+// Demonstrates pipe factory operators for connecting interfaces.
+//
+// Pipe operators:
+//   a >> pipes >> b   — forward A->B
+//   a << pipes << b   — forward B->A
+//   a | pipes | b     — bidirectional (uses BidirectionalMIDI_PipeFactory)
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface ble;
+
+NoteButton button {5, {MIDI_Notes::C[4], Channel_1}};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/borrowed_cc_rotary_encoder.cpp

@@ -0,0 +1,28 @@
+// BorrowedCCRotaryEncoder — shared encoder reference for CC output.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+AHEncoder encoder {0, 2};
+
+BorrowedCCRotaryEncoder enc {
+    encoder,
+    {16, Channel_1},
+    1,
+    4,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_absolute_encoder.cpp

@@ -0,0 +1,27 @@
+// CCAbsoluteEncoder — encoder position mapped to absolute CC value.
+// Original: examples/1. MIDI Output/3. Rotary Encoders/AbsoluteRotaryEncoder/AbsoluteRotaryEncoder.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCAbsoluteEncoder enc {
+    {0, 2},          // encoder pins
+    MIDI_CC::Pan,    // CC address
+    1,               // speed multiplier
+    4,               // pulses per step
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_button.cpp

@@ -0,0 +1,25 @@
+// CCButton — sends CC 127 on press, CC 0 on release.
+// Original: examples/1. MIDI Output/2. Buttons & Switches/1. Momentary Push Buttons/CCButton/CCButton.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCButton button {
+    5,
+    {MIDI_CC::General_Purpose_Controller_1, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_button_latched.cpp

@@ -0,0 +1,24 @@
+// CCButtonLatched — first press sends CC 127, second press sends CC 0.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCButtonLatched button {
+    5,
+    {MIDI_CC::General_Purpose_Controller_1, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_button_latching.cpp

@@ -0,0 +1,24 @@
+// CCButtonLatching — CC 127 while held, CC 0 on release; toggles state.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCButtonLatching button {
+    5,
+    {MIDI_CC::General_Purpose_Controller_1, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_button_matrix.cpp

@@ -0,0 +1,29 @@
+// CCButtonMatrix — grid of CC buttons using row/column scanning.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCButtonMatrix<2, 3> matrix {
+    {0, 1},    // row pins
+    {2, 3, 4}, // column pins
+    {{
+        {16, 17, 18},
+        {19, 20, 21},
+    }},
+    Channel_1,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_buttons.cpp

@@ -0,0 +1,25 @@
+// CCButtons — multiple CC buttons with sequential addresses.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCButtons<4> buttons {
+    {2, 3, 4, 5},
+    {MIDI_CC::General_Purpose_Controller_1, Channel_1},
+    1,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_increment_decrement_buttons.cpp

@@ -0,0 +1,28 @@
+// CCIncrementDecrementButtons — two buttons for CC increment/decrement with optional reset.
+// Original: examples/1. MIDI Output/2. Buttons & Switches/4. RelativeIncrementDecrement/CCIncrementDecrementButtons/CCIncrementDecrementButtons.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCIncrementDecrementButtons buttons {
+    {5, 6},          // increment pin, decrement pin
+    {16, Channel_1}, // CC address
+    1,               // multiplier
+    {0x45, Channel_1}, // reset note (sent when both pressed)
+};
+
+int main() {
+    stdio_init_all();
+    RelativeCCSender::setMode(relativeCCmode::MACKIE_CONTROL_RELATIVE);
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_potentiometer.cpp

@@ -0,0 +1,25 @@
+// CCPotentiometer — analog input mapped to CC value 0-127.
+// Original: examples/1. MIDI Output/1. Potentiometers & Faders/Control-Change-Potentiometer/Control-Change-Potentiometer.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCPotentiometer pot {
+    26,                                     // ADC pin (GPIO 26 = ADC0)
+    {MIDI_CC::Channel_Volume, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_potentiometers.cpp

@@ -0,0 +1,26 @@
+// Multiple CCPotentiometers — several analog inputs mapped to CC.
+// Original: examples/1. MIDI Output/1. Potentiometers & Faders/Multiple-Control-Change-Potentiometers/Multiple-Control-Change-Potentiometers.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCPotentiometer pots[] {
+    {26, {MIDI_CC::Channel_Volume, Channel_1}},
+    {27, {MIDI_CC::Channel_Volume, Channel_2}},
+    {28, {MIDI_CC::Channel_Volume, Channel_3}},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/cc_rotary_encoder.cpp

@@ -0,0 +1,28 @@
+// CCRotaryEncoder — relative CC encoder for DAW parameter control.
+// Original: examples/1. MIDI Output/3. Rotary Encoders/RotaryEncoder/RotaryEncoder/RotaryEncoder.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+CCRotaryEncoder enc {
+    {0, 2},       // encoder pins A and B (constructs AHEncoder)
+    {16, Channel_1}, // CC address
+    1,            // speed multiplier
+    4,            // pulses per step
+};
+
+int main() {
+    stdio_init_all();
+    RelativeCCSender::setMode(relativeCCmode::MACKIE_CONTROL_RELATIVE);
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/note_button.cpp

@@ -0,0 +1,25 @@
+// NoteButton — sends Note On/Off on button press/release.
+// Original: examples/1. MIDI Output/2. Buttons & Switches/1. Momentary Push Buttons/NoteButton/NoteButton.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteButton button {
+    5,                             // push button on GPIO 5
+    {MIDI_Notes::C[4], Channel_1}, // note C4, channel 1
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/note_button_latched.cpp

@@ -0,0 +1,24 @@
+// NoteButtonLatched — first press sends Note On, second press sends Note Off.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteButtonLatched button {
+    5,
+    {MIDI_Notes::C[4], Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/note_button_latching.cpp

@@ -0,0 +1,24 @@
+// NoteButtonLatching — Note On while held, Note Off on release; toggles state.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteButtonLatching button {
+    5,
+    {MIDI_Notes::C[4], Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/note_button_matrix.cpp

@@ -0,0 +1,30 @@
+// NoteButtonMatrix — grid of note buttons using row/column scanning.
+// Original: examples/1. MIDI Output/2. Buttons & Switches/1. Momentary Push Buttons/NoteButtonMatrix/NoteButtonMatrix.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteButtonMatrix<2, 3> matrix {
+    {0, 1},    // row pins
+    {2, 3, 4}, // column pins
+    {{
+        {MIDI_Notes::C[4], MIDI_Notes::D[4], MIDI_Notes::E[4]},
+        {MIDI_Notes::F[4], MIDI_Notes::G[4], MIDI_Notes::A[4]},
+    }},
+    Channel_1,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/note_buttons.cpp

@@ -0,0 +1,25 @@
+// NoteButtons — multiple note buttons with sequential addresses.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+NoteButtons<4> buttons {
+    {2, 3, 4, 5},                  // GPIO pins
+    {MIDI_Notes::C[4], Channel_1}, // base address
+    1,                             // increment between addresses
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/note_chord_button.cpp

@@ -0,0 +1,33 @@
+// NoteChordButton — plays a chord on button press.
+// Original: examples/1. MIDI Output/2. Buttons & Switches/1. Momentary Push Buttons/NoteChordButton/NoteChordButton.ino
+// Note: bankable variant (with Transposer) requires bankable output elements (not yet extracted).
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+constexpr Channel channel = Channel_1;
+
+NoteChordButton buttons[] {
+    {2, {MIDI_Notes::C[4], channel}, Bass::Double + Chords::Major},
+    {3, {MIDI_Notes::D[4], channel}, Bass::Double + Chords::Minor},
+    {4, {MIDI_Notes::E[4], channel}, Bass::Double + Chords::Minor},
+    {5, {MIDI_Notes::F[4], channel}, Bass::Double + Chords::MajorFirstInv},
+    {6, {MIDI_Notes::G[4], channel}, Bass::Double + Chords::MajorSecondInv},
+    {7, {MIDI_Notes::A[4], channel}, Bass::Double + Chords::MinorSecondInv},
+    {8, {MIDI_Notes::B[4], channel}, Bass::Double + Chords::Diminished},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/pb_absolute_encoder.cpp

@@ -0,0 +1,26 @@
+// PBAbsoluteEncoder — encoder position mapped to 14-bit Pitch Bend.
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+PBAbsoluteEncoder enc {
+    {0, 2},   // encoder pins
+    Channel_1,
+    127,      // large multiplier for PB's 14-bit range
+    4,        // pulses per step
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/pb_potentiometer.cpp

@@ -0,0 +1,25 @@
+// PBPotentiometer — analog input mapped to 14-bit Pitch Bend.
+// Original: examples/1. MIDI Output/1. Potentiometers & Faders/Pitch-Bend-Potentiometer/Pitch-Bend-Potentiometer.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+PBPotentiometer pot {
+    26,        // ADC pin
+    Channel_1,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/pc_button.cpp

@@ -0,0 +1,25 @@
+// PCButton — sends Program Change on button press.
+// Original: examples/1. MIDI Output/4. Program Changers/PCButton/PCButton.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+PCButton pcBtn {
+    2,
+    {MIDI_PC::Steel_Drums, Channel_1},
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/examples/output/program_changer.cpp

@@ -0,0 +1,36 @@
+// ProgramChanger — sends different program changes based on selector state.
+// Original: examples/1. MIDI Output/4. Program Changers/Program-Changer/Program-Changer.ino
+
+#include "pico/stdlib.h"
+#include "pico/cyw43_arch.h"
+#include <cs_midi.h>
+
+using namespace cs;
+
+BluetoothMIDI_Interface midi;
+
+ProgramChanger<4> programChanger {
+    {{
+        MIDI_PC::Acoustic_Grand_Piano,
+        MIDI_PC::Rock_Organ,
+        MIDI_PC::Steel_Drums,
+        MIDI_PC::Pad_2,
+    }},
+    Channel_1,
+};
+
+IncrementDecrementSelector<4> selector {
+    programChanger,
+    {2, 3},
+    Wrap::Wrap,
+};
+
+int main() {
+    stdio_init_all();
+    if (cyw43_arch_init()) return 1;
+    Control_Surface.begin();
+    while (true) {
+        Control_Surface.loop();
+        sleep_ms(1);
+    }
+}

tests/lwipopts.h

@@ -0,0 +1,19 @@
+#ifndef _LWIPOPTS_H
+#define _LWIPOPTS_H
+
+#define NO_SYS                      1
+#define LWIP_SOCKET                 0
+#define LWIP_NETCONN                0
+#define LWIP_RAW                    1
+#define LWIP_DHCP                   1
+#define LWIP_DNS                    1
+#define LWIP_IGMP                   1
+#define LWIP_NETIF_HOSTNAME         1
+#define LWIP_NETIF_STATUS_CALLBACK  1
+#define LWIP_UDP                    1
+#define LWIP_TCP                    1
+#define MEM_SIZE                    4096
+#define MEMP_NUM_UDP_PCB            6
+#define MEMP_NUM_TCP_PCB            4
+
+#endif

tests/pico_sdk_import.cmake

@@ -0,0 +1,120 @@
+# This is a copy of <PICO_SDK_PATH>/external/pico_sdk_import.cmake
+
+# This can be dropped into an external project to help locate this SDK
+# It should be include()ed prior to project()
+
+# Copyright 2020 (c) 2020 Raspberry Pi (Trading) Ltd.
+#
+# Redistribution and use in source and binary forms, with or without modification, are permitted provided that the
+# following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
+# disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
+# disclaimer in the documentation and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products
+# derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+# INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+if (DEFINED ENV{PICO_SDK_PATH} AND (NOT PICO_SDK_PATH))
+    set(PICO_SDK_PATH $ENV{PICO_SDK_PATH})
+    message("Using PICO_SDK_PATH from environment ('${PICO_SDK_PATH}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT} AND (NOT PICO_SDK_FETCH_FROM_GIT))
+    set(PICO_SDK_FETCH_FROM_GIT $ENV{PICO_SDK_FETCH_FROM_GIT})
+    message("Using PICO_SDK_FETCH_FROM_GIT from environment ('${PICO_SDK_FETCH_FROM_GIT}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_PATH} AND (NOT PICO_SDK_FETCH_FROM_GIT_PATH))
+    set(PICO_SDK_FETCH_FROM_GIT_PATH $ENV{PICO_SDK_FETCH_FROM_GIT_PATH})
+    message("Using PICO_SDK_FETCH_FROM_GIT_PATH from environment ('${PICO_SDK_FETCH_FROM_GIT_PATH}')")
+endif ()
+
+if (DEFINED ENV{PICO_SDK_FETCH_FROM_GIT_TAG} AND (NOT PICO_SDK_FETCH_FROM_GIT_TAG))
+    set(PICO_SDK_FETCH_FROM_GIT_TAG $ENV{PICO_SDK_FETCH_FROM_GIT_TAG})
+    message("Using PICO_SDK_FETCH_FROM_GIT_TAG from environment ('${PICO_SDK_FETCH_FROM_GIT_TAG}')")
+endif ()
+
+if (PICO_SDK_FETCH_FROM_GIT AND NOT PICO_SDK_FETCH_FROM_GIT_TAG)
+  set(PICO_SDK_FETCH_FROM_GIT_TAG "master")
+  message("Using master as default value for PICO_SDK_FETCH_FROM_GIT_TAG")
+endif()
+
+set(PICO_SDK_PATH "${PICO_SDK_PATH}" CACHE PATH "Path to the Raspberry Pi Pico SDK")
+set(PICO_SDK_FETCH_FROM_GIT "${PICO_SDK_FETCH_FROM_GIT}" CACHE BOOL "Set to ON to fetch copy of SDK from git if not otherwise locatable")
+set(PICO_SDK_FETCH_FROM_GIT_PATH "${PICO_SDK_FETCH_FROM_GIT_PATH}" CACHE FILEPATH "location to download SDK")
+set(PICO_SDK_FETCH_FROM_GIT_TAG "${PICO_SDK_FETCH_FROM_GIT_TAG}" CACHE FILEPATH "release tag for SDK")
+
+if (NOT PICO_SDK_PATH)
+    if (PICO_SDK_FETCH_FROM_GIT)
+        include(FetchContent)
+        set(FETCHCONTENT_BASE_DIR_SAVE ${FETCHCONTENT_BASE_DIR})
+        if (PICO_SDK_FETCH_FROM_GIT_PATH)
+            get_filename_component(FETCHCONTENT_BASE_DIR "${PICO_SDK_FETCH_FROM_GIT_PATH}" REALPATH BASE_DIR "${CMAKE_SOURCE_DIR}")
+        endif ()
+        FetchContent_Declare(
+                pico_sdk
+                GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
+        )
+
+        if (NOT pico_sdk)
+            message("Downloading Raspberry Pi Pico SDK")
+            if (${CMAKE_VERSION} VERSION_GREATER_EQUAL "3.17.0")
+                FetchContent_Populate(
+                        pico_sdk
+                        QUIET
+                        GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                        GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
+                        GIT_SUBMODULES_RECURSE FALSE
+
+                        SOURCE_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-src
+                        BINARY_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-build
+                        SUBBUILD_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-subbuild
+                )
+            else ()
+                FetchContent_Populate(
+                        pico_sdk
+                        QUIET
+                        GIT_REPOSITORY https://github.com/raspberrypi/pico-sdk
+                        GIT_TAG ${PICO_SDK_FETCH_FROM_GIT_TAG}
+
+                        SOURCE_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-src
+                        BINARY_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-build
+                        SUBBUILD_DIR ${FETCHCONTENT_BASE_DIR}/pico_sdk-subbuild
+                )
+            endif ()
+
+            set(PICO_SDK_PATH ${pico_sdk_SOURCE_DIR})
+        endif ()
+        set(FETCHCONTENT_BASE_DIR ${FETCHCONTENT_BASE_DIR_SAVE})
+    else ()
+        message(FATAL_ERROR
+                "SDK location was not specified. Please set PICO_SDK_PATH or set PICO_SDK_FETCH_FROM_GIT to on to fetch from git."
+                )
+    endif ()
+endif ()
+
+get_filename_component(PICO_SDK_PATH "${PICO_SDK_PATH}" REALPATH BASE_DIR "${CMAKE_BINARY_DIR}")
+if (NOT EXISTS ${PICO_SDK_PATH})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' not found")
+endif ()
+
+set(PICO_SDK_INIT_CMAKE_FILE ${PICO_SDK_PATH}/pico_sdk_init.cmake)
+if (NOT EXISTS ${PICO_SDK_INIT_CMAKE_FILE})
+    message(FATAL_ERROR "Directory '${PICO_SDK_PATH}' does not appear to contain the Raspberry Pi Pico SDK")
+endif ()
+
+set(PICO_SDK_PATH ${PICO_SDK_PATH} CACHE PATH "Path to the Raspberry Pi Pico SDK" FORCE)
+
+include(${PICO_SDK_INIT_CMAKE_FILE})