2 Digit Object/Product Counter

The 2 Digit Object/Product Counter project is a purely hardware-based sequential counting system that operates without any microcontroller or programmed software. Powering the circuit begins with a 9-volt battery connected through a battery connector, stabilized by a 7805 voltage regulator to supply a steady 5V to the digital and analog ICs. The primary sensing mechanism utilizes an IR sensor pair to detect physical objects passing through their optical path. When an object breaks the beam or reflects infrared light, it triggers a voltage change monitored by an LM358 operational amplifier configured as a comparator. The analog output from the LM358 then triggers a 555 timer IC configured to produce a clean, debounced digital pulse. This pulse acts as a clock signal for the downstream counting stage, which consists of two cascaded CD4033 decade counter/seven-segment decoder ICs. Each pulse advances the count by one. The CD4033 ICs take the incoming clock pulses and directly drive two common cathode seven-segment displays, with current-limiting 150-ohm resistors protecting the display segments. The circuit utilizes 10K and 100K resistors along with a 10K potentiometer for biasing and sensitivity adjustments, while a 220uF capacitor helps filter power supply noise. Together, these analog and digital building blocks seamlessly track and visually display two-digit counts up to 99.