Simple example for sending note on/off messages

[kamilmac]

Something along those lines (taken form simplecoremidi lib for python):

from simplecoremidi import send_midi
import random
from time import sleep

def play_a_scale():
    root_note = 60
    channel = 1
    note_on_action = 0x90
    major_steps = [3, 1, 24, 3 , 3, 1, 14, 28, 0 , 12 , 35]
    velocity = 127

note = root_note
for step in major_steps:
    rand = random.randint(0,100) / 100
    note = root_note + step 

    send_midi((note_on_action | channel,
               note,
               velocity ))
    sleep(0.05)
    send_midi((note_on_action | channel,
               note,
               0))
    sleep(0.3)

if __name__=='__main__':
    while True:
        play_a_scale()

Great job!

[sstark]

Choose first available destination, send midi note 0x40 to midi channel 1, let it play for 2 seconds:

package main

import (
    "fmt"
    "github.com/youpy/go-coremidi"
    "time"
)

func main() {
    dests, err := coremidi.AllDestinations()
    for _, d := range dests {
        fmt.Printf("Dest: %s, %s\n", d.Manufacturer(), d.Name())
    }
    client, err := coremidi.NewClient("me")
    if err != nil {
        fmt.Println(err)
        return
    }
    port, err := coremidi.NewOutputPort(client, "me")
    if err != nil {
        fmt.Println(err)
        return
    }
    noteOn := coremidi.NewPacket([]byte{0x91, 0x40, 127})
    noteOff := coremidi.NewPacket([]byte{0x81, 0x40, 127})
    err = noteOn.Send(&port, &dests[0])
    if err != nil {
        fmt.Println("could not send midi packet")
    }
    time.Sleep(time.Second * 2)
    err = noteOff.Send(&port, &dests[0])
    if err != nil {
        fmt.Println("could not send midi packet")
    }
}