• 2.7V to 5V logic supply.
• Optional supply for Back-light and Buzzer 5V to 10V.
• Optional V_EE supply for extended temperature LCD unit.
• I2c Slave mode interface.
• Programmable i2c address.
• Programmable LCD Back-light brightness.
• Programmable Back-light on time.
• Programmable Buzzer frequency.
• Programmable Buzzer on time.
• NTC temperature compensated contrast regulation.
• 8K Byte serial EEPROM, for menu strings, and non-volatile store of application parameter values.
• Customized serial EEPROM i2c address.
• Reduced EMI for key-scan.
• Hardware write protection of menu and setup values in the upper quadrant of the serial EEPROM.
• Text write to LCD function.
• Buzzer on/off control.
• LCD back-light on/off control.
• Application i2c port has minimal traffic.

I2cMenu is an i2c interfaced unit for cost effective, simple and flexible menu-type selection, including the ability to write application specific text to the LCD module (the menu function can be used for the display selection). Menu navigation and parameter selection is done using two SOFT keys and two scroll keys. A serial EEPROM contains the menu structure, and setup values for the unit. These can be pre-loaded to the EEPROM, therefore saving on application code space. The upper quadrant can be locked containing the menu and setup and the remainder used for the application. The application also has on/off control over the LCD back-light and buzzer. Own i2c ID, Buzzer frequency, Back-light brightness and on times are setup in an area in the serial EEPROM, and can be modified by the application.

The I2cMenu unit relation to the application is a Slave, which makes it possible to implement a software i2c port on the application controller.

Setup information and setpoints are contained in the unit and can therefore be easily moved from one application to another. Units can also be bussed for multi point entry/display systems.

The i2c address of the serial EEPROM is selectable via flash-pads, and can be customized in the customer code EPROM of the LPC, in this way it possible the have several I2cMenu devices on the bus. The unit has two basic modes, a menu mode and a display mode. At startup the menu mode is active, and menu navigation and parameter selection can be done.

While the menu is at the first level, display messages are accepted and displayed, at the same time the menu is exited. Pressing any key will bring up the menu mode again. During display mode the Master is disabled to save data memory. During menu mode the Slave receive buffer is limited to 3 bytes. Buzzer and LCD back-light control is functional in both menu and display mode.