Dear Sir,
i implement Toll plaza system based on vehicle category interface with 8051 microcontroller i have some hardware issues all the codes are work fine great work when i enter the vechicle category section for pressing 1 or 2 the keypad sometimes read otherwise proceed next section showing blank screen for entering amount when i entered amount it took the amount in spacing or sometimes empty screen same as vechicle category section selection * for erasing amount also give problem then i pressed # it takes garbage value e.g 31326 . Sir please give me solution to this problem or mail me the correct code if possible .