esp32-audio.service goes to ~/.config/systemd/users/ # Enable it so it starts automatically at login systemctl --user enable esp32-audio.service # Start it immediately systemctl --user start esp32-audio.service # Check its status systemctl --user status esp32-audio.service # Causes user login to linger sudo loginctl enable-linger littlesophia NEED TO LOCK IN ID OF ESP32 SO ITS ALWAYS THE SAME PORT #Get ID udevadm info -a -n /dev/ttyACM0 | grep serial EXAMPLE RESPONSE (radxa) littlesophia@radxa-cubie-a7z:~/serial_audio_catcher$ udevadm info -a -n /dev/ttyACM0 | grep serial ATTRS{product}=="USB JTAG/serial debug unit" ATTRS{serial}=="B4:3A:45:AD:CA:90" ATTRS{serial}=="xhci-hcd.41.auto" CREATE rules file and add listing sudo nano /etc/udev/rules.d/99-esp32.rules add this line SUBSYSTEM=="tty", ATTRS{idVendor}=="303a", ATTRS{idProduct}=="1001", ATTRS{serial}=="B4:3A:45:AD:CA:90", SYMLINK+="ttyESP32_A" Now device should be locked at port "/dev/ttyESP32_A" # Test Record parec -d esp32.monitor --file-format=wav > test.wav