openhab, io16, reversing the switch logic

[xsherlock]

Hi,

I'm using io16 to drive inexpensive relay board to do light switching in home.

I'd love to see a way to reverse the logic of the switch in openhab.

When the output is defined as true in the example. 

 

tinkerforge:io16outb0.defaultState=true

 

The relay is disengaged, does not take power, but the switch in the site map is ON. I'd love see it OFF in that state at that moment

 

Of course it is possible to start the output in the defaultstate=false.

But that implies some annoyances that are hard to accept. First the setup starts with applying about 0.4W of power per relay. that will end up with unnessesary 20-30W residual load on the whole house during the day when the light are off.

 

Second in case openhab crashes/reboots i end up with all ligths on !! all the time.

 

So the most elegant way would be to revese the logic on the sitemap only, is there a way to do it?

 

regards

Maciej 

 

 

 

[theo]

May be a mapping could help you out: https://github.com/openhab/openhab/wiki/Explanation-of-Sitemaps#mappings

 

[xsherlock]

My openhab skills still wait to get improved in order to be sure if I can make it with the mapping.

 

In the meantime I ordered other relay board that has jumpers to do set the low/high logic. Unfortunately it is 12V so it will require additional power.

 

It looks that all 5v  8x relay boards on the internet are the clones of the same design and take low signal to energize the relay. For some reason.

[theo]

For the mapping thing you can try this:

Switch item=<itemname> mappings=["OFF"="ON", "ON"="OFF"]

[xsherlock]

Thanks for the hint. I did check this solution, but unfortunately it come with hell lot of compromises.

First the switch is no longer a switch in a gui but a set of two buttons.

Second the bulb icon is still reversed

Third the group master switch works on the original state and not mapped one. -switches the relays on when master_off is pressed

 

So it is a dead end.

Maciej

[theo]

That's bad. Another way solving this problem could be using "virtual" switch items which are connected to the ui and rules which map the events from the "virtual" switches to the io-16 devices.

 

Theo