adding conts and comments

cmd/audio-player/looper/main.go

@@ -27,13 +27,13 @@ LICENSE
 /*
 Pi Setup:
 pull master
-  $sudo nano main.go
-chage file variable at top of function to be wav file that you have put onto the pi (hint: spc command)
 navigate to /go/src/bitbucket.org/ausocean/av/cmd/audio-player/looper
+  $sudo nano main.go
+chage file variable at top of function to be wav file that you have put onto the pi (hint: spc command to put a new file on the pi)
 and build
 edit rc.local to run looper at boot
   $sudo nano /etc/rc.local
-paste this in after comments but before 'exit 0':
+paste this in after comments but before 'exit 0': -----------------------------------------------------------
 
 exec 2> /tmp/rc.local.log      # send stderr from rc.local to a log file
 exec 1>&2                      # send stdout to the same log file
@@ -44,9 +44,18 @@ AUDIOPATH=/home/pi/go/src/bitbucket.org/ausocean/av/cmd/audio-player/looper
 cd $AUDIOPATH
 
 ./looper &
-
+-----------------------------------------------------------------------------------------------------------------
   $systemctl enable rc-local
   $sudo systemctl start rc-local.service
+after starting the service the looping should start straight away
+
+Useful commands:
+	$cat /tmp/rc.local.log
+	$sudo systemctl status rc-local.service
+	$cat audio.log (in looper directory)
+
+On computer
+	$scp something.wav pi@192.168.1.106:/home/pi
 */
 
 package main
@@ -62,24 +71,27 @@ import (
 )
 
 func main() {
-	file := "48khz.wav" //"5mStartToEndOfTrials.wav"
+	soundFile := "48khz.wav" //"5mStartToEndOfTrials.wav"
+	soundcardPath := "/usr/share/doc/audioInjector/asound.state.RCA.thru.test"
+	logFile := "audio.log"
 
 	//making log file
-	_, err := os.Stat("audio.log")
+	_, err := os.Stat(logFile)
 	if !os.IsNotExist(err) {
-		err := os.Remove("audio.log")
+		err := os.Remove(logFile)
 		if err != nil {
 			log.Fatalf("fatal: error clearing file: %v", err)
 		}
 	}
 
-	f, err := os.OpenFile("audio.log", os.O_RDWR|os.O_CREATE, 0666) //chage to empty each time
+	f, err := os.OpenFile(logFile, os.O_RDWR|os.O_CREATE, 0666) //chage to empty each time
 	if err != nil {
-		log.Fatalf("fatal: error opening file: %v", err)
+		log.Fatalf("fatal: error opening file %s: %v", logFile, err)
 	}
 	defer f.Close()
 	log.SetOutput(f)
 
+	//alsactl ensures that the sound will be played through the correct soundcard
 	path, err := exec.LookPath("alsactl")
 	if err != nil {
 		log.Fatalf("fatal: didn't find 'alsactl' executable\n")
@@ -88,12 +100,12 @@ func main() {
 	}
 
 	for {
-		cmdInit := exec.Command("alsactl", "-f", "/usr/share/doc/audioInjector/asound.state.RCA.thru.test", "restore")
+		cmdInit := exec.Command("alsactl", "-f", soundcardPath, "restore")
 		err := cmdInit.Run()
 		if err == nil {
 			break
 		}
-		log.Printf("fatal(ish): cmd.Run() for alsactl failed with '%s'\n", err)
+		log.Printf("fatal(ish): cmd.Run() for 'alsactl' failed with '%s'\n", err)
 		time.Sleep(1 * time.Second)
 	}
 
@@ -108,9 +120,9 @@ func main() {
 	numPlays := 0
 	for {
 		numPlays++
-		log.Printf(" Number of times played: %d\n", numPlays)
+		log.Printf(" Play number: %d\n", numPlays)
 
-		cmd := exec.Command("play", file)
+		cmd := exec.Command("play", soundFile)
 
 		var stdoutBuf, stderrBuf bytes.Buffer
 		stdoutIn, _ := cmd.StdoutPipe()
@@ -122,7 +134,7 @@ func main() {
 
 		err := cmd.Start()
 		if err != nil {
-			log.Fatalf("fatal: cmd.Start() failed with '%s'\n", err)
+			log.Fatalf("fatal: cmd.Start() for 'play' failed with '%s'\n", err)
 		}
 
 		var wg sync.WaitGroup
@@ -138,7 +150,7 @@ func main() {
 
 		err = cmd.Wait()
 		if err != nil {
-			log.Fatalf("fatal: cmd.Run() failed with %s\n", err)
+			log.Fatalf("fatal: cmd.Run() for 'play' failed with %s\n", err)
 		}
 		if errStdout != nil || errStderr != nil {
 			log.Fatal("fatal: failed to capture stdout or stderr\n")