Feature request picoreplayer: Play state to GPIO

[Aki7]

Thanks Paul, this stuff seems to be real "hard core"

[Aki7]

Ok, Vers. 0.2 after some polishing:

#!/bin/sh

# --------------------------------------------------------------------------------------------------------------------------
# Script polls "pcp mode" every 500 ms and sets a GPIO when squeezelite is playing.
# Aki 9/2020 - Home: https://forums.slimdevices.com/showthread.php?110277-Feature-request-picoreplayer-Play-state-to-GPIO 
# --------------------------------------------------------------------------------------------------------------------------
# Vers 0.2: Cleanup of GPIO on exit. Reentrance cleared. -k kills running instance. Clean reaction on 'pcp mode' outages.

BASE_GPIO_PATH=/sys/class/gpio
ScriptName=$(basename -- "$0")
#Parameters=$@

function msg () {
  echo "$(date +"%T") $ScriptName: $@";
} # function msg

function err () {
  echo "$(date +"%T") $ScriptName: Error: $1" >&2; exit 1 
} # function err

function cleanup () {  
  if [ -e $BASE_GPIO_PATH/gpio$myGPIO ]; then # GPIO initialized    
    echo "$((!$PlayVal))" > $BASE_GPIO_PATH/gpio$myGPIO/value # Set to off state
    echo "$myGPIO" > $BASE_GPIO_PATH/unexport
  fi # GPIO de-initialized
  exit 0 
} # on Exit

function Usage () {
  echo ""
  echo "PlayMode to GPIO ($ScriptName) sets a GPIO when squeezelite is playing."
  echo "--------------------------------------------------------------------"
  echo "Usage: sudo $0 -g GPIO [-s n] [-f] [-v] [-b] [-k] [-h]"
  echo ""
  echo "-g : GPIO-number"
  echo "-s : Set value for \"play\" mode: 0,1. Default=1 sets GPIO to 3V when playing"
  echo "-v : Verbose output from background"
  echo "-f : run in foreground with verbose output"
  echo "-b : Blink mode, GPIO is blinking when playing"    
  echo "-k : Kill running $ScriptName" 
  echo "-h : Shows this help"
  echo ""
  echo "Examples:"
  echo "---------"
  echo "  sudo $0 -g 27        : Sets GPIO27 to 3V when playing"  
  echo "  sudo $0 -g 4 -s 0 -f : Sets GPIO4  to 0V when playing, running in foreground"
  echo "  sudo $0 -g 4 -s 1 -v : Sets GPIO4  to 3V when playing, running in background with output"
  echo "  sudo $0 -g27 -b      : Sets GPIO27 to 3V, blinking when playing"   
  echo "  sudo $0 -k           : Kills running $ScriptName"  
  echo ""
exit 1
} # function Usage

function Loop () { 
  trap cleanup INT TERM # cleanup GPIO on exit
  while true; do  
    MODE=`pcp mode 2> /dev/null`
    if [ ! "$MODE" ]; then MODE=unknown; fi # no result, wget error
            
    if [ "$MODE" = "play" ] && $Blink; then # Blink on play
      actGPIOval=$(cat $BASE_GPIO_PATH/gpio$myGPIO/value) 
      echo "$((!$actGPIOval))" > $BASE_GPIO_PATH/gpio$myGPIO/value
    fi # Blink on play      
    
    if [ ! "$MODE" = "$OldMode" ]; then # MODE change
      if [ "$MODE" = "play" ] || [ "$MODE" = "pause" ] || [ "$MODE" = "stop" ] || [ "$MODE" = "unknown" ]; then # valid or empty MODE 
        msgtxt="pcp mode is \"$MODE\"."
        if [ "$MODE" = "play" ]; then GPIOval=$PlayVal; else GPIOval=$((!$PlayVal)); fi # Set GPIO value        
        if [ ! "$GPIOval" = "$oldGPIOval" ]; then
          msgtxt="Set GPIO$myGPIO to $GPIOval. ${msgtxt}"
          echo "$GPIOval" > $BASE_GPIO_PATH/gpio$myGPIO/value
          oldGPIOval=$GPIOval
        fi # GPIO val change
        msg $msgtxt         
      else # invalid MODE
        msg "\"pcp mode\" results to invalid mode \"$MODE\", should be play, pause, stop" 
      fi # valid/invalid MODE
      OldMode=$MODE
    fi # MODE change 
    sleep 0.5
  done # while true
} # function Loop

############
### Main ###
############

# Parameter
# ---------

if [ ! $1 ]; then Usage; fi # No Param, please give at least the GPIO

# Defaults
myGPIO=
PlayVal=1 # active high
Verbose=false # no output from loop when daemonized
foreground=false # no more need to foreground
Blink=false # stoy active

while getopts g:s:vfbkh opt 
do 
  case $opt in
    g ) # Check for valid GPIO
        if [ "$OPTARG" -ge 2 ] && [ "$OPTARG" -le 27 ] 
          then myGPIO=$OPTARG
          else err "\"$OPTARG\" is not a valid GPIO, please use 2 .. 27"; fi # Check for valid GPIO
      ;;
    s ) # Check parameter for setting GPIO to 0 or 1 when playing
        if [ $OPTARG ]; then # Set GPIO to 0 or 1 when playing
          if [ "$OPTARG" -eq 0 ] || [ "$OPTARG" -eq 1 ] 
            then PlayVal=$OPTARG 
            else err "\"$OPTARG\" is not a valid GPIO state, please use 0 or 1"; fi
        fi # Check parameter for setting GPIO to 0 or 1 when playing
      ;;
    v ) Verbose=true;;
    f ) foreground=true;;
    b ) Blink=true;;
    k ) msg "Killing running instance."; killall -15 $ScriptName;;        
    h ) Usage;;
    [?]) Usage;;
  esac
done
if [ ! $myGPIO ]; then err "Mandatory parameter -g \"GPIO\" is missing"; fi

# Kill old instance, if exists
for pid in $(pidof $ScriptName); do    
  if [ ! $pid = $$ ]; then
    msg "Killing old instance (pid $pid) of $ScriptName"
    kill -15 $pid
    until [ ! -e $BASE_GPIO_PATH/gpio$myGPIO ]; do 
      sleep 0.1 # Give the exit routine some time. on pi 3b+ 0.1s is enough
    done # Wait for ols exit routine finished
  fi # old instance found     
done # Kill old instance

# Init
# ----

# Wait for squeezelite to come online
wt=0
until pids=$(pidof squeezelite squeezelite-dsd); do
  sleep 1; wt=$(($wt+1))
  msg "Waited $wt seconds for for squeezelite ..." 
  if [ "$wt" -ge 60 ]; then err "Waited too long for squeezelite"; fi
done

# Init GPIO
if [ ! -e $BASE_GPIO_PATH/gpio$myGPIO ]; then # Init GPIO
  msg "Export GPIO$myGPIO to userspace"
  echo "$myGPIO" > $BASE_GPIO_PATH/export
fi # Init GPIO
msg "Set GPIO$myGPIO as an output"
echo "out" > $BASE_GPIO_PATH/gpio$myGPIO/direction

# Start loop
# ----------

if $foreground; then # run in foreground:
  msg "Foreground loop polling, with output. Stop with \"ctrl-c\"."
  Loop
else # daemonize
  if $Verbose; then
    msg "Background loop polling with output. Stop with \"sudo $0 -k\" or restart of script." 
    Loop &
  else # Background loop polling with output
    msg "Background loop polling. Stop with \"sudo $0 -k\" or restart of script." 
    Loop > /dev/null 2>&1 &
  fi # Background loop polling
fi # Start fore- or background loop polling
exit

# End of Program

Working fine, but polling uses >10% more CPU and energy and gives a little delay. Suggestion:

The Squeezelite call of "Power On/Off Script" gets some more states:

Now:

2: Init
1: On
0 :Off

Future:

5: stop
4: play
3: pause
2: init
1: on
0: off

So everyone can build nice status LEDs or switch his perifery to his needs.

By the way: "stop" vs. "off" could get some clarification ;-)

Scripting in unknown terrain is the real adventure game

Have fun
Aki

[sakos]

hi sakos,

Generally speaking the "pcp commands" are only a simple interface into LMS commands. They can only respond as LMS responds.

Having said that, reading the documentation we should get an "undefined" value. Maybe we have coded a default value of stop.

<playerid> mode ?

The "mode" command allows to query the player state and returns one of "play", "stop" or "pause". If the player is off, "mode ?" returned value is undefined.

Example:

Request: "04:20:00:12:23:45 mode ?<LF>"
Response: "04:20:00:12:23:45 mode stop<LF>"

I have added your post to the list of things todo.

regards
Greg

Where can I find this code in Github? Maybe I can do this small change myself.

[Greg Erskine]

hi sakos,

99% of piCorePlayer is just shell scripts, so the code is on your SD card.

I'd probably start looking at pcp-lms-functions.

There is the extra complication that pCP uses readonly extensions linked to in RAM.

regards
Greg

[sakos]

hi sakos,

99% of piCorePlayer is just shell scripts, so the code is on your SD card.

I'd probably start looking at pcp-lms-functions.

There is the extra complication that pCP uses readonly extensions linked to in RAM.

regards
Greg

Ok, found the pcp_lms_mode() function, but could not see any mapping.

pcp_lms_mode() {
REQUEST=$(pcp_lms_build_request "$NAME" mode ?)
RESULT=$(pcp_lms_build_result result _mode)
pcp_lms_json_request

pcp_lms_build_result() {
#Should be at least 2 arguments, result is almost always the first.
RLOOP="["
pcp_lms_build_loop $@
REQ="$RLOOP]"
# escape the brackets [ ] for egrep and sed
echo $REQ | sed 's/\[/\\\[/' | sed 's/\]/\\\]/'
}

pcp_lms_build_loop() {
if [ "$1" != "" ]; then
[ "$RLOOP" == '[' ] && RLOOP="$RLOOP"$1"" ||RLOOP="$RLOOP,"$1""
shift
NEXT=$@
[ "$NEXT" != "" ] && pcp_lms_build_loop $NEXT
fi
}


Do I understand well?

[Greg Erskine]

Yes.

From the LMS CLI help:

<playerid> mode ? 
The "mode" command allows to query the player state and returns one of "play", "stop" or "pause". If the player is off, "mode ?" returned value is undefined. 
Example: 
	Request: "04:20:00:12:23:45 mode ?<LF>" 
	Response: "04:20:00:12:23:45 mode stop<LF>"

So the pcp_lms_mode function handles the "play", "stop" or "pause" responses. It should have extra code to check for undefined and return "off".

[Aki7]

"play"
"stop"
"pause"
"off"
"unknown" - no connect to LMS

?

Aki

[Aki7]

Vers 0.3: When no GPIO is given, green onboard LED led0 will be used. So will run now without parameters. No more sudo necessary.

Aki

##!/bin/sh

# --------------------------------------------------------------------------------------------------------------------------
# pm2gpio script polls "pcp mode" every 500 ms (1 second on Pi Zero) and sets a GPIO when squeezelite is playing.
# Aki 9/2020 - Home: https://forums.slimdevices.com/showthread.php?110277-Feature-request-picoreplayer-Play-state-to-GPIO 
# --------------------------------------------------------------------------------------------------------------------------
# Vers 0.2: Cleanup of GPIO on exit. Reentrance cleared. -k kills running instance. Clear reaction on 'pcp mode' outages.
# Vers 0.3: When no GPIO is given, green onboard LED led0 will be used. So will now run without parameters. No more sudo necessary

BASE_GPIO_PATH=/sys/class/gpio
ScriptName=$(basename -- "$0")

function UpTm () { # Returns UpTime sss.ms
  set `cat -- /proc/uptime`
  echo "$1"
} # function UpTm

function mySudo () {
  echo $@ | sudo sh
} # function mySudo

function msg () {
  echo "$(UpTm) $ScriptName: $@"; #echo "$(date +"%T") $ScriptName: $@";
} # function msg

function err () {
  echo "$(UpTm) $ScriptName: Error: $@" >&2; exit 1 
} # function err, not called from loop -therefore no need to cleanup?

function cleanup () { 
  if [ $PlayGPIO = "0" ]; then # green onboard led0
    mySudo "echo mmc0 >/sys/class/leds/led0/trigger" 
  else # GPIO
    if [ -e $BASE_GPIO_PATH/gpio$PlayGPIO ]; then # GPIO initialized    
      mySudo "echo $((!$PlayVal)) > $BASE_GPIO_PATH/gpio$PlayGPIO/value" # Set to off state
      mySudo "echo $PlayGPIO > $BASE_GPIO_PATH/unexport"
    fi # GPIO de-initialized
  fi # led0 or GPIO
  exit 0 
} # on Exit

function Usage () {
  echo ""
  echo "PlayMode to GPIO ($ScriptName) sets a GPIO when squeezelite is playing."
  echo "--------------------------------------------------------------------"
  echo "Usage: $0 [-g GPIO] [-s n] [-f] [-v] [-b] [-k] [-h]"
  echo ""
  echo "-g : GPIO-number play mode, if not given, green onboard (led0) will be used"
  echo "-s : GPIO-value for play mode [0,1], if not given [1] will be used"
  echo "-f : run in foreground with verbose output"
  echo "-v : verbose output from background"
  echo "-b : blink mode, GPIO is blinking when playing, on on pause"    
  echo "-k : Kill running $ScriptName" 
  echo "-h : Shows this help"
  echo ""
  echo "Examples:"
  echo "---------"
  echo "  $0             : Green onboard LED (led0) on when playing"
  echo "  $0 -b          : Green onboard LED (led0) blinking when playing, on when paused"
  echo "  $0 -g27        : Sets GPIO27 to 3V when playing"  
  echo "  $0 -g27 -b     : Sets GPIO27 to 3V, blinking when playing, on when pause"
  echo "  $0 -g4  -s0 -f : Sets GPIO4  to 0V when playing, running in foreground with output (debug)"
  echo "  $0 -g4  -s1 -v : Sets GPIO4  to 3V when playing, running in background with output (debug)"
  echo "  $0 -k          : Kills running $ScriptName"  
  echo ""
exit 1
} # function Usage

function Loop () { 
  trap cleanup INT TERM # cleanup GPIO on exit
  while true; do  
    MODE=`pcp mode 2> /dev/null`    
    if [ ! "$MODE" = "$OldMode" ]; then # MODE change
      if [ ! "$MODE" ]; then MODE="not available"; fi # no result, wget error
      msg "pcp mode is \"$MODE\"."
      if [ "$MODE" = "play" ] || [ "$MODE" = "pause" ] || [ "$MODE" = "stop" ] || [ "$MODE" = "not available" ]; then # valid or empty MODE
        if [ "$MODE" = "play" ]; then 
          GPIOval=$PlayVal; # on
        elif $blink && [ "$MODE" = "pause" ]; then 
          GPIOval=$PlayVal # on
        else
          GPIOval=$((!$PlayVal)) # off
        fi        
      else # unknown MODE
        msg "\"pcp mode\" results to unknown mode \"$MODE\", should be play, pause, stop" 
      fi # valid/invalid MODE
      OldMode=$MODE
    fi # MODE change       
    
    # blink
    if $blink && [ "$MODE" = "play" ]; then GPIOval="$((!$GPIOval))"; fi # invert, blinking                       
            
    if [ ! "$GPIOval" = "$oldGPIOval" ]; then
      if ! $blink; then msg "Set GPIO$PlayGPIO to $GPIOval."; fi
      if [ $PlayGPIO = "0" ]; then # led0
        if [ $GPIOval = "1" ]; then
          mySudo "echo 1 >/sys/class/leds/led0/brightness"
        else
          mySudo "echo 0 >/sys/class/leds/led0/brightness"
        fi
      else # GPIO
        mySudo "echo $GPIOval > $BASE_GPIO_PATH/gpio$PlayGPIO/value"
      fi
      oldGPIOval=$GPIOval
    fi # GPIO val change        
    sleep 0.5
  done # while true
} # function Loop

############
### Main ###
############

# Parameter
# ---------
#if [ ! $1 ]; then Usage; fi # No Param, please give at least the GPIO
# Defaults
PlayGPIO=0 # default green onboard led0
PlayVal=1 # default active high
foreground=false # no more need to foreground
verbose=false # no output from loop when daemonized
blink=false # stay active
oldGPIOval=0

while getopts g:s:fvbkh opt 
do 
  case $opt in
    g ) # Check for valid Play GPIO
        if [ "$OPTARG" -ge 2 ] && [ "$OPTARG" -le 27 ] 
          then PlayGPIO=$OPTARG
          else err "Play GPIO \"$OPTARG\" is not a valid GPIO, please use 2 .. 27"; fi # Check for valid GPIO
      ;;
    s ) # Check parameter for setting GPIO to 0 or 1 when playing
        if [ $OPTARG ]; then # Set GPIO to 0 or 1 when playing
          if [ "$OPTARG" -eq 0 ] || [ "$OPTARG" -eq 1 ] 
            then PlayVal=$OPTARG 
            else err "Play-value \"$OPTARG\" is not a valid GPIO state, please use 0 or 1"; fi
        fi # Check parameter for setting GPIO to 0 or 1 when playing
      ;;
    f ) foreground=true;;
    v ) verbose=true;;
    b ) blink=true;;
    k ) msg "Killing running instance."; sudo killall -15 $ScriptName;;        
    h ) Usage;;
    [?]) Usage;;
  esac
done

# Kill old instance, if exists
for pid in $(pidof $ScriptName); do    
  if [ ! $pid = $$ ]; then
    msg "Killing old instance (pid $pid) of $ScriptName"
    mySudo "kill -15 $pid"
    sleep 0.3 # Give the exit routine some time. on pi 3b+ 0.1s is enough
  fi # old instance found     
done # Kill old instance

# Init
# ----

# Wait for squeezelite to come online
wt=0
until pids=$(pidof squeezelite squeezelite-dsd); do
  sleep 1; wt=$(($wt+1))
  msg "Waited $wt seconds for for squeezelite ..." 
  if [ "$wt" -ge 60 ]; then err "Waited too long for squeezelite"; fi
done

# Init GPIO
if [ $PlayGPIO = "0" ]; then # led0
  msg "Disable mmc0 trigger on led0"
  mySudo "echo none >/sys/class/leds/led0/trigger"
else # GPIO
  if [ ! -e $BASE_GPIO_PATH/gpio$PlayGPIO ]; then # Init GPIO
    msg "Export GPIO$PlayGPIO to userspace"
    mySudo "echo $PlayGPIO > $BASE_GPIO_PATH/export"
  fi # Init GPIO
  msg "Set GPIO$PlayGPIO as an output"
  mySudo "echo out > $BASE_GPIO_PATH/gpio$PlayGPIO/direction"
fi # led0 or GPIO

# Call Loop
# ----------

if $foreground; then # foreground:
  msg "Foreground loop polling, with output. Stop with \"ctrl-c\"."
  Loop
else # daemonize
  if $verbose; then # Background loop polling with output
    msg "Background loop polling with output. Stop with \"$0 -k\" or restart of script." 
    Loop &
  else # Background loop polling 
    msg "Background loop polling. Stop with \"sudo $0 -k\" or restart of script." 
    Loop > /dev/null 2>&1 &
  fi # Background loop polling
fi # Start fore- or background loop polling
exit

# End of Program

[sakos]

Yes.

From the LMS CLI help:

<playerid> mode ? 
The "mode" command allows to query the player state and returns one of "play", "stop" or "pause". If the player is off, "mode ?" returned value is undefined. 
Example: 
	Request: "04:20:00:12:23:45 mode ?<LF>" 
	Response: "04:20:00:12:23:45 mode stop<LF>"

So the pcp_lms_mode function handles the "play", "stop" or "pause" responses. It should have extra code to check for undefined and return "off".

Where is the undefined response mapped to "stop", currently? Because "pcp mode" response is "stop" after "pcp power off" command sent. Maybe LMS response is also "stop" in this case?
Disregard my question. Now GPIO control in case of player power off working fine in squeezlite.

[jeroen2]

Vers 0.3: When no GPIO is given, green onboard LED led0 will be used. So will run now without parameters. No more sudo necessary.

This works great, thanks! I wanted to add a simple play/pause button to some of my players and this is precisely what I needed. Just copy/paste and worked 'out of the box'.

Maybe it should be added to the PcP manual pages?