cs-midi-docs/docs/manual/01-getting-started/03-first-input.md

First Input

Original: Getting Started — First Input

A minimal sketch that receives MIDI and drives outputs (LEDs).

MIDI input elements

Input elements listen for specific MIDI messages and update their state. NoteLED drives a GPIO pin high when its note is active:

NoteLED led {25, {MIDI_Notes::C[4], Channel_1}};

An array of LEDs responding to consecutive notes:

NoteLED leds[] {
    {16, MIDI_Notes::C[4]},
    {17, MIDI_Notes::D[4]},
    {18, MIDI_Notes::E[4]},
    {19, MIDI_Notes::F[4]},
};

Value readers store the incoming value without driving hardware:

CCValue ccVal {{MIDI_CC::Channel_Volume, Channel_1}};

Access the current value with ccVal.getValue().

Complete example

#include "pico/stdlib.h"
#include "pico/cyw43_arch.h"
#include <cs_midi.h>

using namespace cs;

BluetoothMIDI_Interface midi;

NoteLED led {25, {MIDI_Notes::C[4], Channel_1}};

CCValue volume {{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 v = volume.getValue();
        (void)v;
        sleep_ms(1);
    }
}