[epsonprojector] Add SDDP discovery

[mlobstein]

This PR adds SDDP discovery for epson projectors using the core SDDP discovery service.

Depends on openhab/openhab-core#4237

[mlobstein]

@lolodomo once this is finished, it should be easy to copy-paste into sonyprojector.

[lolodomo]

@lolodomo once this is finished, it should be easy to copy-paste into sonyprojector.

Sony is also using its own protocol named SDAP for discovery. But SDDP is also supported. I need host, port and model to create a thing. I see these fields are provided by object SddpDevice. Do you know why port field is a String ? I see you are not using it, any reason ?

For the model, I cannot be sure that they will provide the exact same string I am using. One option would be to let the user define the model. I can also try to set it in case I can identify an approximative matching.

Unfortunately, I will not be able to test that because my model has no Ethernet connection.

[jlaur]

@mlobstein - do you know if there are any projectors supporting only AMX, but not SDDP? I'm wondering if it would still make sense to keep AMX support in case some older projectors doesn't support other discovery methods?

[andrewfg]

Do you know why port field is a String ?

In SddpDevice we extract the port from one of the headers being the part after the colon in a the header which contains ipAddress:port. Normally this should indeed be an integer. However since the respective header comes from the remote device, it could possibly contain a non numeric value. And rather than throw a number conversion exception in core, we pass that as a string to the binding developer so they can decide themselves. Often the port returned is 1902 which is simply the port of the SDDP multicast group, so often not much use when sending unicast commands to a device. We basically provide it "just in case"..

[mlobstein]

@mlobstein - do you know if there are any projectors supporting only AMX, but not SDDP? I'm wondering if it would still make sense to keep AMX support in case some older projectors doesn't support other discovery methods?

My ancient-came-out-in-2009 projector that I use for testing supports only AMX. The newer ones seem to support both. I was worried about getting duplicate discovery results for those in the supports both column and that was my deciding factor for removing AMX.

[mlobstein]

@lolodomo once this is finished, it should be easy to copy-paste into sonyprojector.

Sony is also using its own protocol named SDAP for discovery. But SDDP is also supported. I need host, port and model to create a thing. I see these fields are provided by object SddpDevice. Do you know why port field is a String ? I see you are not using it, any reason ?

For the model, I cannot be sure that they will provide the exact same string I am using. One option would be to let the user define the model. I can also try to set it in case I can identify an approximative matching.

Unfortunately, I will not be able to test that because my model has no Ethernet connection.

For Sony and the ethernetconnection thing, I would think you would just use the default port of 53484 for PJ Talk. The model is trickier... Ideally the model specified by the SDDP packet could be matched up with one of the available models specified by the thing definition and if there was no match, fall back to the AUTO option. But I admit I don't know much about the sonyprojector implementation to say if that is an acceptable outcome.

[lolodomo]

For Sony, yes I will use default port 53484 and AUTO as model.

[jlaur]

I was worried about getting duplicate discovery results for those in the supports both column and that was my deciding factor for removing AMX.

It's possible to have overlapping discovery (i.e. multiple methods) as long as they are kept consistent (see #14919). In particular they need the same representation property.

[mlobstein]

I was worried about getting duplicate discovery results for those in the supports both column and that was my deciding factor for removing AMX.

It's possible to have overlapping discovery (i.e. multiple methods) as long as they are kept consistent (see #14919). In particular they need the same representation property.

Ok, I put AMX discovery back as it was.

[andrewfg]

Remove dashes from mac to prevent duplicate discovery results with AMX

Just for the avoidance of doubt .. are you making sure to use lower case in both representation properties?

[mlobstein]

Remove dashes from mac to prevent duplicate discovery results with AMX

Just for the avoidance of doubt .. are you making sure to use lower case in both representation properties?

That is a good point.. In the AMX packet it is uppercase. So I will put toUpperCase() on the SDDP side so that the representation property of both match..

[lolodomo]

@jlaur @andrewfg : is it ok for you now ?

[jlaur]

is it ok for you now ?

Yes, my only concern was if discovery support for older devices would be dropped, but since the AMX discovery is left intact, this is fully addressed.

[andrewfg]

is it ok for you now ?

Yes, I think so.

[lsiepel]

Can be merged when #16802 (comment) is handled.

[lolodomo]

LGTM, thank you