DSO138 2.4 inch TFT Digital Pocket-size Oscilloscope Kit

DSO138 2.4 inch TFT Digital Pocket-size Oscilloscope Kit is a popular, open-source educational tool that provides hobbyists and students with a portable solution for waveform analysis. This kit features an ARM Cortex-M3 processor (STM32F103C8) and a crisp 2.4-inch color TFT display to render electrical signals with impressive clarity. Consequently, it serves as an excellent entry-level diagnostic tool for those who need to visualize low-frequency signals without investing in expensive benchtop equipment. Furthermore, the DSO138 offers a hands-on learning experience, as it allows users to explore the fundamental principles of digital signal processing. Therefore, you can effectively use this pocket-size oscilloscope to troubleshoot basic circuits, verify PWM signals, or learn the basics of electronic instrumentation.

Key Features:

• High-Resolution Display: The integrated 2.4-inch color TFT LCD provides a clear 320 x 240 resolution, making waveform details easy to observe.
• Automatic Waveform Capture: Users can utilize the “AUTO” mode to instantly adjust settings for an optimal signal view.
• Triggering Capabilities: The device supports Auto, Normal, and Single trigger modes, ensuring it captures both periodic and non-periodic events.
• Waveform Storage: It includes a memory function that allows you to freeze and save a waveform for later analysis.
• Built-in Test Signal: Features a 1KHz / 3.3V square wave test signal to help users calibrate the probe and verify the device’s functionality.

Technical Specifications:

• Analog Bandwidth: 0 − 200 KHz
• Sampling Rate: 1 Msps max
• Vertical Sensitivity: 10mV/Div − 5V/Div
• Timebase Range: 10μs/Div − 500s/Div
• Input Impedance: 1M Ω
• Maximum Input Voltage: 50Vpk (1:1 probe)
• Supply Voltage: 9V DC (8V − 12V range)
• Power Consumption: ≈ 120 mA

Mechanical Specifications:

• Processor: STM32F103C8 (ARM Cortex-M3)
• Display Type: 2.4-inch Color TFT LCD
• Input Connector: BNC Standard
• Control Interface: On-board slide switches and push buttons

Dimensions:

• PCB Size: ≈ 117 mm x 76 mm
• Screen Size: 2.4 inch (Diagonal)
• Overall Thickness: ≈ 15 mm (with components mounted)
• Weight: ≈ 70 g (Main board and display)

Pinout and Wiring:

• Power Input (J2): Connect a 9V DC power supply center-positive barrel jack.
• Signal Input (J1): Connect the BNC oscilloscope probe here to measure your target circuit.
• Test Signal Output: Locate the terminal loop on the PCB to access the 1KHz square wave signal.
• Programming Header: Use the SWD or UART headers for advanced users who wish to update the firmware.

Datasheet Reference:

• Download DSO138 User Manual and Technical Guide

Commonly Used in:

• Electronics Education: Teaching students how to use an oscilloscope in university or school labs.
• Hobbyist Workbenches: Providing a low-cost signal visualization tool for DIY electronics and Arduino projects.
• Field Repairs: Offering a portable diagnostic solution for simple audio and low-speed digital equipment.

Applications:

• PWM Signal Verification: Checking the duty cycle and frequency of pulse-width modulation signals from microcontrollers.
• Audio Signal Testing: Visualizing sine waves and identifying clipping or distortion in audio amplifier circuits.
• Sensor Data Monitoring: Observing analog voltage changes from sensors like potientiometers or temperature modules.

Equivalent Models:

• DSO150 (Shell): An upgraded version featuring a rotary encoder and a protective plastic enclosure.
• DSO-Shell: A functionally identical model often sold in a complete housing for better durability.
• FNIRSI-138: A popular manufacturer variant of the DSO138 circuit design, however, check for firmware compatibility before flashing.

Package Includes:

• 1 x DSO138 2.4 inch TFT Digital Pocket-size Oscilloscope Kit (Unsoldered)
• 1 x BNC-to-Alligator Clip Probe