Monitoring how many people enter or exit a space is essential in many environments such as offices, factories, libraries, and meeting halls. Manual tracking is unreliable and impractical, especially when continuous counting is required. This creates a clear need for a simple, automatic, and cost effective employee counting system that can provide real time occupancy data without complex software or computing systems.
The project presented here addresses this requirement using a hardware based approach built around an IR sensor and CD4026 decade counter ICs. Unlike microcontroller based solutions, this design is fully electronic, easy to build, and suitable for practical deployment as well as learning purposes. The author’s prototype is shown in Fig. 1.
Components Required
Semiconductors
- IC1, IC2 – CD4026B decade counter/7-Segment driver
Resistors (-watt, 5%)
- R1 – 2.2kilo-ohm
- R2, R3 – 330-ohm
Capacitors
- C1 – 4.7uF,25V electrolytic
Miscellaneous
- DIS1, DIS2 – 7-Segment CC display (LTS6980HR/LTS543
- S1 – Push-to-on switch
- CON1,CON2
- 2-pin connector
- IR sensor module
- Designed PCB or general-purpose board
- IC bases (optional)
- Connecting wires
- Enclosure/cabinet
- Screws, spacers, etc.
Employee Counter Circuit and Working
Fig. 3 shows the circuit diagram of the employee counter using an IR sensor module. The circuit is built around two CD4026 decade counter and 7 segment driver ICs (IC1 and IC2), two common cathode 7 segment displays (DIS1 and DIS2, such as LTS6980HR or LTS543), and a few additional components.
The two CD4026 ICs are cascaded to count and display numbers from 00 to 99. An IR sensor module detects movement of a person passing through the entrance, and each detection increments the displayed count on the 7 segment displays. Other components include a 2.2 kilo ohm resistor (R1) for stable operation, 330 ohm resistors (R2 and R3) for display current limiting, and a push to on switch (S1) for resetting the counter to zero.
The working of the employee counter is based on pulse detection and counting. The IR sensor continuously emits infrared radiation and monitors its reflection. When a person passes in front of the sensor, the IR beam is interrupted, generating a digital pulse at its output. This pulse is applied to the clock input of IC1, causing the count to increment by one. Since the CD4026 includes an inbuilt 7 segment decoder and driver, it directly drives the display DIS1.
IC1 drives the units digit display (DIS1), while its carry out output is connected to the clock input of IC2, which drives the tens digit display (DIS2). This cascading arrangement enables counting from 00 to 99. A reset switch (S1) is provided to simultaneously clear both counters and reset the display to zero.
Proper grounding and the use of current limiting resistors ensure reliable operation. The sensitivity of the IR sensor can be adjusted using its onboard pre-set to achieve accurate detection and minimise false triggering. The entire circuit operates from a regulated 5V DC power supply or adapter.
Construction and testing
An actual-size, single-sided PCB layout for the employee counter is shown in Fig. 4, and its component layout is shown in Fig. 5. After assembling the circuit on the designed PCB, mount it inside a suitable enclosure with proper openings for the displays, switches, LED, and IR sensor. Ensure that all power supply pins are connected correctly to +5V and ground. Alternatively, the circuit may also be assembled on a general-purpose PCB if you do not have the designed PCB.
Mount the display and reset switch (S1) on the front panel of the enclosure. Position the IR sensor module at a suitable height and angle so that it can reliably detect a person crossing its path. The sensor output is connected to the clock input of IC1, while the carry out of IC1 is connected to IC2 for cascading operation. The outputs of both ICs are wired to their respective 7 segment displays with proper pin configuration.
For testing, apply a regulated 5V DC supply to the circuit. Initially, both displays should show 00, indicating the reset condition. Move a hand or walk in front of the IR sensor to simulate entry detection. The count should increase by one for each detection.
Continue testing to verify correct counting up to 99 and ensure that the tens digit increments properly after every ten counts. Press the reset switch to confirm that the display returns to zero instantly. If the counter skips counts or behaves erratically, check IR sensor alignment, verify all wiring connections, and ensure that the 5V power supply is stable and noise free.
Installation in a company environment
Installing this employee counter requires proper placement and mounting to ensure accurate operation. The system should be installed at a single controlled entry or exit point, such as a main door or corridor, so that every person is counted without duplication.
Mount the IR sensor at a height of approximately 3 to 4 feet on one side of the doorway, aligned with the expected path of movement. Ensure that the sensor is not exposed to direct sunlight or highly reflective surfaces, as these may cause false triggering.
The display unit should be installed at a clearly visible location, such as near the entrance or at a security desk, while the circuit should be housed in a suitable protective enclosure. A suggested wall mounted enclosure with its internal view is shown in Fig. 2 for reference; however, a different enclosure may be selected based on requirements.
Use a regulated 5V DC power supply, preferably with surge protection or UPS backup, to ensure reliable operation. Before deployment, adjust the sensor sensitivity and test the setup by allowing people to pass through the doorway while verifying correct counting. For best accuracy, ensure that only one person passes through the detection zone at a time. Periodically inspect sensor alignment and keep the sensor surface clean to maintain consistent performance.
