4 digits digital objects counter with Laser - WiFi ESP32C3 +TM1637

This is a compact, Wi-Fi enabled 4-digit digital object counter built around the ESP32-C3 microcontroller and a TM1637 4-digit LED display. It is designed for accurately counting objects using a laser beam and photoresistor (LDR), while also offering manual counting and browser-based control.

The counter is lightweight, easy to use, and ideal for production lines, packaging, laboratories, educational projects, and general object counting applications.

Demo Video

How It Works

A <1 mW laser module is directed at the LDR (Light Dependent Resistor) mounted on the side of the counter. Whenever an object interrupts the laser beam, the counter automatically increments or decrements the count, depending on the selected operating mode.

The LDR sensitivity can be calibrated to suit different room lighting conditions, ensuring reliable operation.

Features

Automatic Object Counting

• Counts objects whenever the laser beam is interrupted.

• Uses an LDR (Light Dependent Resistor) as the optical sensor.

• Suitable for both indoor and controlled lighting environments.

UP Count and DOWN Count Modes

Choose how the counter behaves:

• UP Count Mode: Counts upward (0, 1, 2, 3...).

• DOWN Count Mode: Counts downward from a preset value (e.g. 3, 2, 1, 0...).

Manual Counting

Three buttons are provided on the top of the unit:

• UP – Increase the count.

• DOWN – Decrease the count.

• RESET – Reset the counter.

For rapid adjustment, press and hold the UP or DOWN button for approximately 3 seconds to enable fast counting.

Browser-Based Control

The built-in ESP32-C3 creates a browser-based user interface, allowing users to:

• Increase or decrease the count remotely.

• Reset the counter.

• Enter any desired count value directly.

• Select UP Count or DOWN Count mode.

• Enable or disable the LDR sensor.

• Calibrate the LDR.

• Access all counter functions from a phone, tablet, or computer.

A screenshot of the user interface is shown below.

LDR Calibration

Lighting conditions vary from room to room. If the photoresistor does not respond correctly to laser interruptions, simply press the Calibrate button in the browser interface. The counter will automatically adjust its sensing threshold for the current ambient lighting.

Calibration is optional and only needs to be performed when necessary.

Disable the LDR Sensor

If you only want to use the device as a manual digital counter, the LDR function can be disabled. When disabled, interruptions to the laser beam are ignored, and counting is performed only using the buttons or the browser interface.

Memory Function

The counter automatically saves the current count value in non-volatile memory.

For example:

• Current count: 2345

• Power is switched OFF.

• When powered ON again, the display will still show 2345.

There is no need to reset or re-enter the count after a power outage.

Dimensions

10.5cmx5.6cmx1.9cm

Weight

90gm

Power Supply

• Operating Voltage: 5 V DC

• USB-C power input

• Can be powered using any standard 5 V USB phone charger or power bank.

Optional Wireless Transmitter Feature

An optional transmitter version is available.

In this mode, the counter wirelessly transmits its count value to a larger P3 or P5 digital object counter/display.

This allows the compact counter to be installed close to the objects being counted, while the larger display is mounted at a convenient viewing location for operators or spectators.

This feature is ideal for:

• Manufacturing and production lines

• Warehouses

• Packaging stations

• Industrial counters

• Public counting displays

Key Features

• 4-digit TM1637 LED display

• ESP32-C3 microcontroller

• Wi-Fi browser-based control

• Automatic laser/LDR object detection

• UP Count and DOWN Count modes

• Manual count buttons

• Fast count adjustment

• Adjustable LDR calibration

• Optional LDR disable mode

• Non-volatile memory (retains count after power loss)

• USB-C powered (5 V)

• Lightweight and portable

• Optional wireless transmitter for large remote displays

Package Includes:

• 1 x Counter module
• 1 x Laser module