The project is designed to calculate the stamp value for postal operations by measuring the weight of postal letters. Usually in post offices postal letters are measured on a weighing scale that ranges from grams and according to the measurement tariff rate is imposed on it. The project is a precise electronic weighing machine that weighs in grams.
An 8051 series microcontroller is used to measure weight of letter with the help of a weight sensing mechanism through spring loaded variable resistor. The weight is then recorded and microcontroller calculates the price of stamp required. The weight and the price thus calculated is processed by an ADC interfaced to microcontroller that displays it on a LCD screen.