If you are wanting to create 2 zone pads using a piezo to trigger the rim then it isn't that simple (although it is not too difficult). The rim trigger requires a switch closure which is simultaneous with the pad piezo. If you want to use a piezo to provide the signal then it needs to provide two signals - a switch closure to emulate the switch (on the connector ring) AND provide a piezo signal to the connector tip. To do that you need to build a simple circuit such as http://dtxpander.co.uk/DKDI-21.pdf The jumper JP1 is optional, as is D3 - it just gives some options for getting signal levels and triggering correct.
