Shell command volume slider

Chris_Cope · March 22, 2021, 9:01am

I have a volume slider on the GUI that I would like to send a variable shell command to a component.

In automation.yaml in have:

  alias: vol slider
  description: ''
  trigger:
  - platform: state
    entity_id: input_number.218_vol
  condition: []
  action:
  - service: shell_command.218_vol_var
  mode: single`

configuration.yaml I have:

input_number:
  218_vol:
    name: Meridian 218
    initial: 40
    min: 1
    max: 99
    step: 1

and

shell_command: 
  218_vol_var: echo -e '#SVN {{ states('input_number.218_vol') }}' | nc 192.168.1.8 9014

If I replace the argument in the shell with a two-digit number then the device at 192.168.1.8 responds with that command. for example:

shell_command: 
  218_vol_50: echo -e '#SVN 50' | nc 192.168.1.8 9014

This shell would set the volume to ‘50’. Can anyone point out my mistakes as the variable is not working!

tom_l · March 22, 2021, 10:55am

Because you have only used single quotes your quotes open and close here:

shell_command: 
  218_vol_var: echo -e '#SVN {{ states('
                       ^----- Pair ----^

Either escape your single quotes (with another single quote) or use double quotes.

shell_command: 
  218_vol_var: echo -e '#SVN {{ states(''input_number.218_vol'') }}' | nc 192.168.1.8 9014

shell_command: 
  218_vol_var: echo -e '#SVN {{ states("input_number.218_vol") }}' | nc 192.168.1.8 9014

Chris_Cope · March 22, 2021, 11:30am

Unfortunately I have just tried this without success. However I will update my code.

To test this I go to the developer tools and insert a two digit value on the ‘input_number.218_vol’ entity to overcome any potential formatting issues. In addition to this, I am using the GUI slider.
Both scenarios I cant get the variable shell to work. as previously said if I change the variable formatting to a static number in the shell. Then adjust the GUI slider, I get the specified value on the component which is totally expected. This proves to me that my theory is correct but my variable formatting is incorrect.

tom_l · March 22, 2021, 11:35am

Put this in the template editor and check what it resolves to:

echo -e '#SVN {{ states("input_number.218_vol") }}' | nc 192.168.1.8 9014

Also, try this command:

shell_command: 
  218_vol_var: 'echo -e ''#SVN {{ states("input_number.218_vol") }}'' | nc 192.168.1.8 9014'

Chris_Cope · March 22, 2021, 12:53pm

I have not used the template editor tool before - what an incredibly useful tool!

I placed this command into the editor:

echo -e '#SVN {{ states("input_number.218_vol") }}' | nc 192.168.1.8 9014

and received this output:

echo -e '#SVN 26.0' | nc 192.168.1.8 9014

It seems we’re very close to having something that works! ‘00.0’ value is not recognised by the component. I need a ‘00’ value (without the decimal point).

tom_l · March 22, 2021, 1:10pm

For the leading zeros have a play with this formatting option:

echo -e '#SVN {{ "%0.2d"|format(states("input_number.218_vol")) }}' | nc 192.168.1.8 9014

Search for “Python leading zeros” for help. I’d give you the exact format but I can’t remember how it works and am struggling with a very bad internet connection.

Chris_Cope · March 22, 2021, 1:42pm

Thank you!

218_vol_var: echo -e '#SVN {{ (states("input_number.218_vol") | round(0)) }}' | nc 192.168.1.8 9014

provides the following in the Template editor:

echo -e '#SVN 46' | nc 192.168.1.8 9014

This seems to be exactly what I need! But it is still not controlling the component… As this is a command_line string, does it need to be fired upon every state change of the volume entity in the automation?

tom_l · March 22, 2021, 2:28pm

Yes, but that is what your existing trigger will do.

Chris_Cope · March 22, 2021, 10:24pm

for anyone looking in I found the below code to insert a zero in front of a single digit when formating numbers

shell_command:
  218_vol_xx: echo -e '#SVN {{"%02d"|format(states("input_number.218_vol")|int)}}' | nc 192.168.1.8 9014`

still no luck with getting my slider automation to work yet…

Chris_Cope · March 23, 2021, 10:16am

I am going round in circles and I’m convinced that the template in command_line is not working.

for a test i change my automation to:

 alias: vol slider
 description: ''
 trigger:
 - platform: state
   entity_id: input_number.218_vol
 condition: []
 action:
 - service: shell_command.218_vol_up
 mode: single`

the difference being the change in service to:

shell_command.218_vol_up

This shell is a fixed command without templating, when I adjust the volume slider up or down, the component’s volume goes up by one. This is expected and demonstrates the automation is working.

As above I have run my template through the editor and I get the result I’m expecting. Is it possible that command_line is unaware of certain types of templates? any workarounds would be greatly appreciated to get these 2 digits into the shell.

tom_l · March 23, 2021, 12:43pm

What device are you trying to control?

Does it have a log you can interrogate to see what is going on?

Does it have a restful interface?

I use rest commands to control functions of my Yamaha media player that are not implemented in the integration. e.g.

rest_command:
  cinema_dialogue_lift:
    url: "http://10.1.1.17/YamahaExtendedControl/v1/main/setDialogueLift?value={{ ( states('input_number.cinema_dialogue_lift')|float * 2 )|int }}"

Chris_Cope · March 23, 2021, 2:25pm

Another great suggestion from you! thank you for all your time on this.

The device is an audio pre-amplifier. I setup a telnet connection to see what it was receiving and found the non-formatted shell commands from Home Automation are making their way to the device but the formatted shell commands are not. again, this points towards the dynamic formatting…

Chris_Cope · April 2, 2021, 2:46pm

I have now added the shell_command logger to my config.yaml

logger:
  default: info
  logs:
    homeassistant.components.shell_command: debug

For ease of testing, I made a script I can trigger on demand. the first line from the logger at 14:36:32 uses the templating shell_command which does not control my IP device as expected. I notice that it seems to self report the actual input number within Home Assistant.

b'#SVN 25 | nc 192.168.1.8 9014\n'

At 14:37:03 uses this shell_command control the device as expected by ‘manually’ adding the value ‘50’. As you can see the device replies with and behaves as expected

b'!PID Product:"218" SerialNumber:"XXXXXX" VersionNumber:"1.1.240" ZoneName:"Lounge" ProtocolVersion:"3"\n*ACK\n'

Here’s the log:

2021-04-02 14:36:32 DEBUG (MainThread) [homeassistant.components.shell_command] Stdout of command: `echo -e '#SVN {{ states("input_number.meridian_vol") | round(0) }}' | nc 192.168.1.8 9014`, return code: 0:
b'#SVN 25 | nc 192.168.1.8 9014\n'

2021-04-02 14:37:03 DEBUG (MainThread) [homeassistant.components.shell_command] Stdout of command: `echo -e '#SVN 50' | nc 192.168.1.8 9014`, return code: 0:
b'!PID Product:"218" SerialNumber:"XXXXXX" VersionNumber:"1.1.240" ZoneName:"Lounge" ProtocolVersion:"3"\n*ACK\n'

Can anyone help me with this?