doorbell

hello, hope you had a merry christmas, and will have a happy new year!

I found a wireless doorbell, and i would like to know it it would be possible to attach the button of the doorbell, to the TX pin on the arduino, and the receiver to the RX pin, sorta like this:

I think i would then be able to serial print what ever i want, and serial read it with the other arduino. say controll severall motors, even if it just has one button, would this be possible?

I`m trying to convert the wireless doorbell outside from battery to a renewable source such as solar or wind. My problem lies in that the battery required is a 9v.

My first thought was to produce a high enough voltage to charge the 9v but that might require more solar panels than I have. The 2nd idea was to use a lower voltage battery or super-cap as replacement and stepping up the voltage to 9v. I haven`t taken any measurements of current usage but I don`t imagine it could be more than a couple hundred mA while pushing the button and much lower in idle.