Project: Logic Analyzer for ESP32 (CYD)

Version: 1.2

Description

This firmware transforms the ESP32-2432S028 (Cheap Yellow Display) board into a simple two-channel logic analyzer with touch controls. The project was iteratively developed to capture and analyze digital signals, particularly for debugging protocols like NEC from IR remotes.

Hardware

• Board: ESP32-2432S028 "Cheap Yellow Display"
• Channel 1 (CH1): GPIO 22 (Connector CN1)
• Channel 2 (CH2): GPIO 27 (Connector CN1)
  • Note: GPIO 35 (Connector P3) can also be used for CH2, but it may be faulty in some cases.

Features

• Two Channels: Capture and display two independent digital signals.
• Touch Interface: All control is handled via 4 main buttons and 2 additional shift buttons.
• Trigger Modes:
  • AUTO: Continuous capture without synchronization.
  • FALL: Continuous capture synchronized on the falling edge of CH1 or CH2.
  • RISE: Continuous capture synchronized on the rising edge of CH1 or CH2.
  • SINGLE: Single-shot capture on the falling edge of CH1 or CH2. Ideal for capturing non-periodic signals (e.g., from a remote control).
• Timebase Control: The T- and T+ buttons allow for flexible adjustment of the capture time (from 0 to 4000 µs per sample).
• Captured Signal Analysis:
  • In SINGLE mode, after a capture (when "paused"), the signal can be examined in detail.
  • Zooming: The T- and T+ buttons allow you to "zoom in" and "zoom out" on the signal, and the T:us time value on the screen is automatically recalculated.
  • Shifting: Additional <- and -> buttons appear when paused and allow you to shift the viewing area across the entire capture buffer (2048 samples).
• Rendering: Signals are drawn as clear rectangular pulses for ease of analysis.
• Splash Screen: An initial splash screen with the software name and version is displayed on startup.

How to Use

1. Select TRIG Mode: Use the TRIG button to select the desired mode. For capturing a signal from a remote, use SINGLE.
2. Adjust Timebase T-/T+: Set the desired base capture time. A value of around 50us works well for IR signals.
3. Capture:
   • In SINGLE mode, press the green ARM button. The device will enter WAITING... mode. Apply a signal to the CH1 or CH2 input. It will automatically "freeze" after capture.
   • In continuous modes (AUTO, FALL, RISE), capture is ongoing.
4. Analysis (when paused):
   • Use T-/T+ to change the zoom level.
   • Use <-/-> to pan across the waveform.
   • To take a new measurement (in SINGLE) or resume operation (in AUTO/FALL/RISE), press ARM / RUN again.

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Version History

• v1.2 (10.01.2026):
  • Added an initial splash screen on device startup. The code was reorganized using header files.
• v1.1:
  • Initial stable version. All core functionality implemented.