1. Introduction
The PLJ-096OLED-L1 is a cost-effective OLED frequency display module designed for continuous signal frequency measurement. It is primarily used for displaying frequency values in transceivers and similar equipment, and is also suitable for general-purpose frequency measurement. Featuring a unique gate control method and precise gate timing algorithm (non-timed interrupt), this module delivers high measurement accuracy.
2. Key Features
- Compact and aesthetically pleasing design with dual-button operation and simplified circuitry.
- On-board power supply electronic switch supports battery operation with shielding capability.
- Temperature-compensated VC-TCXO timing base ensures high stability with frequency accuracy of ±2.5ppm.
- Unique gate control and algorithm eliminate timing interrupts for enhanced measurement precision.
- Settings are automatically saved to EEPROM, eliminating the need to reset upon power-up.
3. Setup
3.1 Physical Overview and Dimensions
Familiarize yourself with the module's structure and dimensions for proper integration.

3.2 Connections
The module features dedicated ports for power input and signal input. Refer to the diagram below for connection points.

- Power Input: Connect a DC power source between 4.5V and 9V to the '5V IN' port. A 5V supply is recommended for optimal performance.
- Signal Input: Connect the signal to be measured to the 'RF IN' port. The module has a high input impedance.
- Measurement Data Output: The module provides UART serial port output for measurement data.
4. Operation
4.1 Basic Usage
Once powered on and a signal is connected to the 'RF IN' port, the module will automatically begin measuring and displaying the frequency on its 0.96-inch OLED screen. The module supports dual-button operation (K1 and K2) for adjustments such as sensitivity and frequency fine-tuning, as indicated in Figure 3.
4.2 Gate Time
The module offers selectable gate times of 0.1 or 1.0 seconds. This setting affects the measurement accuracy and refresh rate of the display.
4.3 Automatic Settings Save
All settings configured on the module are automatically saved to its EEPROM. This means that your preferences will be retained even after the module is powered off and on again, eliminating the need for re-configuration.
4.4 Operation Demonstration
Watch this video for a demonstration of the frequency meter module in action, measuring various frequencies from a signal generator.
5. Maintenance and Precautions
- Environmental Conditions: Avoid exposing the instrument to high temperatures, excessive humidity, or dusty environments.
- Physical Handling: Prevent severe vibration or physical shock to the module.
- Connector Care: The onboard signal input connector is a fragile component. Handle it gently when inserting or removing plugs to prevent damage.
- Calibration: The clock reference and sensitivity are factory-calibrated using GPSDO. Do not attempt to adjust these settings unless you possess the necessary expertise and equipment.
6. Troubleshooting
- No Display: Ensure the power cable is correctly connected to the '5V IN' port and the power supply is providing the recommended DC 4.5-9V (5V recommended).
- Inaccurate Readings:
- Verify the signal input cable is securely connected to the 'RF IN' port.
- Ensure the power supply is stable and within the recommended voltage range.
- Avoid operating the module in environments with significant electromagnetic interference.
- Do not attempt to re-calibrate the clock reference or sensitivity unless you are certain of the procedure and have appropriate calibration tools.
- Unstable Readings:
- Check for loose connections on both power and signal input.
- Ensure the signal source is stable.
- Minimize external noise or interference.
7. Specifications
The following table details the technical specifications of the PLJ-096OLED-L1 Frequency Meter Module:
| Parameter | Value |
|---|---|
| Product Name | Frequency Display Module |
| Operating Voltage | DC 4.5-9V (5V recommended) |
| Operating Current | < 30mA (Test Condition: DC 5V supply) |
| Display | 0.96-inch OLED |
| Gate Time | 0.1 / 1.0 seconds |
| Measurement Accuracy | 10/1Hz |
| Measurement Range | 1KHz-100MHz |
| Input Impedance | High impedance |
| Timing Stability | ±2.5ppm |
| Measurement Data Output | UART serial output |
| On-board Interfaces | Signal input, power interface |
| Application Scenarios | Radio frequency display, radio frequency measurement, oscillation circuit frequency measurement, crystal oscillator frequency screening, embedded applications, general frequency measurement |
| Size | 2.8 x 2.75 x 1.8cm |
8. User Tips
- For DIY projects, ensure all connections are soldered cleanly and securely to prevent intermittent issues.
- When integrating the module into a larger circuit, consider adding additional shielding if operating in a noisy electrical environment to maintain measurement accuracy.
- Always double-check your power supply voltage before connecting to avoid damaging the module.
9. Warranty and Support
For any technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact the seller directly. Keep your purchase records handy for faster service.
10. Package Contents
The package includes:
- 1 x PLJ-096OLED-L1 Frequency Meter Module
- 1 x Signal Cable
- 1 x Power Cable






