If you are going to build the Interactive Frequency Reader on a 12x5 cm perfboard (like the one shipped in the bag of parts), this is a suggested layout of chips, keypad and LCD: keypad on the lowest row, LCD on the topmost row.
Following these positions you will be able to hide all components under the large keypad and display, plus they will be aligned to each other and most wirings will be easier too (pictures will follow). For example some LCD<->ATmega will be straight bridges, and resistors leads will be long enough to connect the keypad to the PCF8574.
