Domino doesn’t have an expansion bus, can I add additional I/O devices like a D/A converter?
The simplest way to add I/O devices is to use I2C devices. However SPI or 3 wire serial devices can also be used. Domino’s internal A/D is an LTC1298 three-wire serial device. The A/D uses Port1.5-7 for CLK, DATA, and CS. You can easily add one or more D/A’s by using Port1.5 and Port1.6 for the CLK and DATA and Port1.4 for the *LOAD output. We suggest using the LTC1257 12-bit DAC from Linear Technology (or equiv.). The 1257 can be cascaded by daisy chaining the DATA line. See the Micromint APPNOTE on adding an external D/A to DOMINO.
