Hi,

your project seems possible.

Some further suggestions:

- use a readymade 20*1 LCD with internal driver circuit

- in case of using LED, use segment multiplexing, since it need less current driver stages. Then the duty cycle was only 1/8 instead 1/19.

- you can use the AT89S8252, which has already 2kB EEPROM internal

- use T2 sqare wave mode to generate the buzzer tone (P1.0)

- using SPI-ADC was an excellent choice, since using internal ADC can cause many trouble to achieve high resolution.


Peter