Dr. Pepper:
Did you just do that?
The OP mentioned that the bell is a plunger like thing that goes Ding! which would be really close to an old electromagnetic doorbell. The OP mentioned that someone said that most bells worked on 8-12 VDC and he used a car battery to test. So, we don't know the current requirements of the bell. He also mentioned that the distance between the two bells were on the order of 10-15 feet or so. There were 16 codes the OP wanted to create.
So, I got the impression that there is a tour guide doing a demo and just has too much to do to worry about "keying" (from morse code) the required code that they wish to demonstrate. So the "tour guide" pushes a button and someone in the basement responds ringing the second bell with the required response. The "second person" in the basement interprets the code and responds.
I also got the feeling that the OP wanted to select either bell, so then the "tour guide" could do both operations. Later in the thread, there was a hint to put an "electronic interpreter" to respond to the bells.
The real specs of the "ultimate" or the simple system really have not been formally specified.
The OP apparently has rather extensive programming experience and limited, but some "programming in solder". Circuit Cellar's founder refers to "solder as his favorite programming language".
All I really did, was to suggest the PICAXE because of the simple requirements that really doesn't require a development system. The only development system is the USB to miniature phone plug cable. My suggestion is a bit unconventional, but should be very easy to construct and program. The additional development tool required is a crimping tool for the connectors. Probably one of these:
https://www.google.com/url?sa=t&rct...=7bF5dgp7b3-XOmfYnroygw&bvm=bv.59378465,d.cWc The price is out to lunch, but good deals can usually be found on ebay
Build the 118 kit with a few add/subtracts and 3 resistors to create the I2C bus and the interrupt bus. A few connectors get added to the octopus cable basically create an I2C/Interrupt cable, a power cable and a "bell" cable". Then build a I2C daughtercard for the KB encoder with an I2C/Interrupt connector and power cable. The keypad suggested has both a row/columd and single closure interface. The I2C bus chip that I selected is only available in surface mount, but you can buy the chip with the I2C chip mounted to a DIP carrier.
I think it would make the programming extremely simple. It could be as simple as wait for interrupt, read the keys, (prioritize mult-presses) and do the appropriate output. Using some sort of data structure for the bell encoding could be the only complication if one waned to add it.