added sudo

.asoundrc

@@ -1,17 +1,7 @@
-pcm.my_sound_device {
+pcm.hw0mix {
-	type hw
+    type dmix
-	card USB
+    ipc_key 1939 # must be unique
-#	card PCH
+    slave { pcm "hw:Zero" }
-#	card Headphones
-	device 0
 }
 
-pcm.my_sound_device_with_converter {
+pcm.!default hw0mix
-	type plug
-	slave {
-		pcm my_sound_device
-		format S16_LE
-	        channels 2
-		rate 48000
-	}
-}

README.md

@@ -12,7 +12,12 @@ Hardware
 - Buttons connected to the Raspberry pi GPIO as shown in the schema to debounce noisy contacts  
 ![dog-trainer-schema](assets/dog-trainer-schema.png)
 
-- USB speaker with a microphone e.g. [Jabra Speak 410](https://www.jabra.com/_/media/Jabra_VXi_Product-Documentation/Jabra-SPEAK-410-Series/technical-specifications/RevB/Jabra-Speak-410-Techsheet-A4-290420-Web.pdf)
+- USB speaker with a microphone e.g. [Jabra Speak 410](https://www.jabra.com/_/media/Jabra_VXi_Product-Documentation/Jabra-SPEAK-410-Series/technical-specifications/RevB/Jabra-Speak-410-Techsheet-A4-290420-Web.pdf) or [Codec Zero](https://www.raspberrypi.com/products/codec-zero/)
+
+- for the `Codec Zero` make follwoing changes
+> `sudo nano /boot/config.txt`  
+`#dtparam=audio=on`  
+`dtoverlay=rpi-codeczero`
 
 - microSD card 8GB
 
@@ -22,7 +27,7 @@ Operating system
 ----------------
 Install [Raspberry Pi Imager](https://www.raspberrypi.com/news/raspberry-pi-imager-imaging-utility/) into your notebook. Launch it and choose `Raspberry Pi OS Lite` to write into the microSD card
 
-Power on the Raspberry pi and finish the installation process. Log into its console using either:
+Power on the `Raspberry Pi` and finish the installation process. Log into its console using either:
 - ethernet/wifi from your notebook: `ssh pi@raspberrypi`
 - connected keyboard and monitor
 - serial port
@@ -33,7 +38,7 @@ Once you are logged into the `Raspberry pi` console update your system
 > `sudo apt update`  
 `sudo apt upgrade`
 
-and install `git`. It will be used to download the `dog-trainer` 
+Install `git`. It will be used to download the `dog-trainer` 
 > `sudo apt install -y git`
 
 Recordings must be edited a little bit therefore some audio processing tool is needed. Install `ffmpeg` which will do the job  
@@ -52,13 +57,17 @@ Go into the newly created directory
 Configuration
 -------------
 
-First try using default audio device for playback and recording. Edit `dog-trainer.py` and activate `PLAY_DEVICE="default"` and `REC_DEVICE="default"`
+Check your Raspberry pi board pin layout and make sure your buttons GPIOs match `PINS = [17, 22, 27]` from `dog-trainer.py`
+> `pinout`
+
+Try using default audio device for playback and recording. Edit `dog-trainer.py` and activate `PLAY_DEVICE="default"` and `REC_DEVICE="default"`
 > `nano dog-trainer.py`
 
 Skip to the next section `Run it!`. If either playback or recording does not work check your sound cards
-> `aplay -L | grep ^hw:CARD=`
+> `aplay -L | grep ^hw:CARD=`  
+`arecord -L | grep ^hw:CARD=`
 
-If your sound device is other then `USB` then change the line `card USB` in ALSA config
+Put your sound device name `"hw:Zero"` or `"hw:USB"` into the ALSA config file
 > `nano .asoundrc`
 
 Install the ALSA config file
@@ -82,14 +91,18 @@ If your username and group is other then `pi` and `pi` then also run
 > `sed -i "s#User=pi#User=$USER#" dog-trainer.service`  
 `sed -i "s#Group=pi#Group=$(id -gn)#" dog-trainer.service`
 
-Install the systemd service file
+> `sed -i "s#User=pi#User=$USER#" sound-init.service`  
-> `sudo mv dog-trainer.service /etc/systemd/system/`
+`sed -i "s#Group=pi#Group=$(id -gn)#" sound-init.service`
+
+Install the systemd service files
+> `sudo mv dog-trainer.service /etc/systemd/system/`  
+`sudo mv sound-init.service /etc/systemd/system/`
 
 Reload systemd manager configuration
-> `systemctl daemon-reload`
+> `sudo systemctl daemon-reload`
 
 Enable the `dog-trainer` service at boot time and also run it
-> `systemctl enable --now dog-trainer`
+> `sudo systemctl enable --now dog-trainer`
 
 If it does not work check logs
 > `journalctl -f -u dog-trainer`
@@ -100,4 +113,7 @@ Set volume for playback and recording
 Launch soundcard mixer
 > `alsamixer`
 
-Press F6 to select a soundcard. Find your USB sound device in the list e.g. `Jabra Speak 410 USB`. Press F4 and use up/down arrow keys to set recording volume and repeat also for the playback (F3). Make sure it is not muted. Press (m) to toggle mute. Press ESC to exit.
+Press F6 to select a soundcard. Find your USB sound device in the list e.g. `Jabra Speak 410 USB`. Press F4 and use up/down arrow keys to set recording volume and repeat also for the playback (F3). Make sure it is not muted. Press (m) to toggle mute. Press ESC to exit.
+
+To preserve audio setting after the boot run
+> `sudo alsactl store`

dog-trainer.py

@@ -4,16 +4,13 @@ from datetime import datetime
 import subprocess
 import sys
 
-# PLAY_DEVICE = "default"  # Playback/recording through the PulseAudio sound server
+PLAY_DEVICE = "default"  # as defined in '~/.asoundrc'
-# REC_DEVICE = "default"  # Playback/recording through the PulseAudio sound server
+REC_DEVICE = "plughw:Zero"  # as listed by 'arecord -L'
-
-PLAY_DEVICE = "my_sound_device_with_converter"  # as defined in '~/.asoundrc'
-REC_DEVICE = "my_sound_device"  # as defined in '~/.asoundrc'
 
 MAX_RECORDING_TIME = 30  # limit recordings to only e.g. 30 seconds long
-TRIM_RECORDING_END = 0.8  # remove the clicking noise from the end of recordings
+TRIM_RECORDING_END = 0.6  # remove the clicking noise from the end of recordings
 RECORD_BUTTON_PRESS_TIME = 2  # pressing and holding a button longer then e.g. 2 seconds triggers recording otherwise playing
-PINS = [17, 23]  # listen to changes on this GPIOs e.g. [4, 17, 23, 0, 5, 6]
+PINS = [17, 22, 27]  # listen to changes on this GPIOs e.g. [4, 17, 23, 0, 5, 6]
 GPIO.setmode(GPIO.BCM)  # use BCM pin layout
 GPIO.setwarnings(False)
 
@@ -40,8 +37,7 @@ def terminate_recording(proc, pin):
             "-of",
             "default=noprint_wrappers=1:nokey=1",
             f"recording_temp_{pin}.wav",
-        ],
+        ], check=True, stdout=subprocess.PIPE,
-        stdout=subprocess.PIPE,
     ).stdout.decode("utf-8")
     subprocess.call(
         [
@@ -66,7 +62,8 @@ def terminate_recording(proc, pin):
 
 
 def play(file):
-    subprocess.call(["aplay", "-D", PLAY_DEVICE, file])
+    print(f"Playing {file}")
+    subprocess.run(["aplay", f"-D{PLAY_DEVICE}", file], check=True)
 
 
 def play_sound(pin):
@@ -86,20 +83,17 @@ def record_sound(pin):
     proc = subprocess.Popen(
         [
             "arecord",
-            "-D",
+            f"-D{REC_DEVICE}",
-            REC_DEVICE,
+            "-fS16_LE",
-            "-f",
+            "-r48000",
-            "S16_LE",
+            "-c2",
-            "-r",
+            f"-d{MAX_RECORDING_TIME}",
-            "16000",
-            "-c",
-            "1",
-            "-d",
-            f"{MAX_RECORDING_TIME}",
             f"recording_temp_{pin}.wav",
         ]
     )
     print(f"Recording in progress (max {MAX_RECORDING_TIME} seconds)...")
+    time.sleep(0.5)
+    play_beep()
     wait_for_button_release_or_timeout(pin, MAX_RECORDING_TIME)
     print("GPIO went HIGH - terminating recording")
     play_beep()
@@ -121,7 +115,6 @@ def handle_pin(pin):
 
     if time.time() - timeout_start >= RECORD_BUTTON_PRESS_TIME:
         # Pin was LOW for longer time; recording
-        play_beep()
         record_sound(pin)
     else:
         # Pin was LOW for shorter time; playing

dog-trainer.service

@@ -1,6 +1,7 @@
 [Unit]
 Description=Dog Trainer
-After=sound.target
+After=sound-init.service
+Requires=sound-init.service
 
 [Service]
 Type=simple

sound-init.service

@@ -0,0 +1,14 @@
+[Unit]
+Description=Sound Initialization Service
+PartOf=dog-trainer.service
+
+[Service]
+Type=simple
+User=pi
+Group=pi
+ExecStart=/bin/sh -c 'cat /dev/zero | aplay -Ddefault -fS16_LE -c2 -r 48000'
+Restart=always
+RestartSec=3
+
+[Install]
+WantedBy=multi-user.target