Select presets with command line

[adbrt]

I would like to skip using the web server part and just configure everything through GPIO, even without MIDI controllers, so it would be nice to control various parameters directly through the command line.

I don't know if there is a nicer way of doing that, but for now I used virtual MIDI port and emulated MIDI commands:

midiemu.sh - run this @ reboot with sudo crontab -e

#!/bin/bash

# Load the snd-virmidi module
sudo modprobe snd-virmidi

sudo pipedalconfig --restart

input_port=32:0
output_port=33:0

aconnect -d -i $input_port
aconnect -d -o $output_port

# Connect the virtual MIDI input to the virtual MIDI output
aconnect $input_port $output_port

selectpreset.sh

#!/bin/bash

# Check if an argument is provided
if [ $# -eq 0 ]; then
  echo "Usage: $0 <decimal_input or preset_name>"
  exit 1
fi

input=$1

# Check if the input is a decimal or a string
if [[ "$input" =~ ^[0-9]+$ ]]; then
  # Input is a decimal
  decimal_input=$input
else
  # Input is a string
  json_content=$(cat /var/pipedal/presets/Default+Bank.bank)

  # Search for the order of the preset in the list
  order=$(jq -r --arg name "$input" '.presets | map(.preset.name) | index($name)' <<< "$json_content")

  # Check if a matching preset was found
  if [ "$order" == "null" ]; then
    echo "Preset with name '$input' not found."
    exit 1
  fi

  echo "Found preset with name '$input'"
  decimal_input=$(printf "%02X" "$((order + 0))")

fi

amidi -p hw:4,0 -S "C0 $decimal_input" && echo Selected preset number $decimal_input

Example usage:

pi@gtrpi:~ $ ./selectpreset.sh solo
Found preset with name 'solo'
Selected preset number 09

pi@gtrpi:~ $ ./selectpreset.sh 1
Selected preset number 1

[FoolHen]

Hi @adbrt I ended up doing something similar but in a python script. It directly binds the buttons connected to the GPIO pins to a MIDI note. A possibility could be to add different signals for double click or long press as well. Also, I created a post about continuing the development of pipedal if you are interested: #147

Steps:

• Install alsa_midi python library
• Create midi.py file with the content below.
• Add a line with the text snd_virmidi to the file /etc/modules. This starts the virtual midi ports when the rpi boots up.
• Create /etc/systemd/system/midi-gpio.service file (to execute the python script when the rpi boots up) with the content below (replacing with the name of your user folder):
• run sudo systemctl enable midi-gpio.service

midi.py:

import time
from alsa_midi import SequencerClient, WRITE_PORT, NoteOnEvent, NoteOffEvent
from gpiozero import Button
from signal import pause

# Init GPIO Buttons

button1 = Button(pin=17, pull_up=False, bounce_time=None)
button2 = Button(pin=27, pull_up=False, bounce_time=None)


# return first element in array that contains VirMidi
def getVirMidiPorts():
    return [p for p in client.list_ports(input=True) if "VirMIDI" in p.name]

client = SequencerClient("GPIO-Midi Client")

# print("outports:")
# print(client.list_ports(output=True))
# print("inports:")
# print(client.list_ports(input=True))

inport = client.create_port("GPIO-Midi out", caps=WRITE_PORT)

virmidi_ports = getVirMidiPorts()

if len(virmidi_ports) == 0:
    print("Could not find virtual MIDI ports. Please add 'snd-virmidi' to the file '/etc/modules'. Exiting...")
    exit(1)

source_port = virmidi_ports[0]

print("Selected source port: ", source_port)

inport.connect_to(source_port)

def triggerNote(note):
    print(f"Sending note: {note}")
    client.event_output(NoteOnEvent(note=note, velocity=64, channel=0))
    client.drain_output()
    client.event_output(NoteOffEvent(note=note, channel=0))
    client.drain_output()
    time.sleep(0.2)

note1 = 60
note2 = 62

print("Connected")
button1.when_pressed = lambda: triggerNote(note1)
button2.when_pressed = lambda: triggerNote(note2)

pause()
client.close()

midi-gpio.service:

[Unit]
[After=multi-user.target](http://after=multi-user.target/)

[Service]
WorkingDirectory=/home/<user>/
User=<user>
ExecStart=/usr/bin/python /home/<user>/midi.py
Restart=always

[Install]
[WantedBy=multi-user.target](http://wantedby=multi-user.target/)

[rerdavies]

@FoolHen Do you need a resistor on the switch, or can you just hook a momentary contact switch directly?

[FoolHen]

It is not strictly necessary but recommended, to protect the rpi if the GPIO is misconfigured as an output. 1K or 10K Ohms is a good protection.