User Manual & Installation Guide
English documentation for international users. Buy or renew PRO on the purchase page; troubleshooting in FAQ.
📦 What You Need
Windows desktop app
- Operating system: Windows 10 or Windows 11 (64-bit recommended)
- Installer / EXE — request the current Windows demo build via email (public GitHub installer temporarily removed while we ship a hardened build). 30-day demo; PRO license by email after purchase.
- PRO license key — emailed after payment; use the same email when activating
💡 Quick tip: Install and run the desktop app like any Windows program. Python is not needed for daily use.
ESP32 firmware (one-time flash)
PRO purchases include a separate email with a zip of pre-compiled .bin files and flash.bat. You do not need Arduino IDE or source code.
- Python 3 on Windows (for
esptool only) — python.org, enable “Add to PATH”
- esptool: in Command Prompt inside the unzipped folder:
pip install esptool
- USB driver — CP210x or CH340 if no COM port appears in Device Manager
Hardware
- ESP32 development board (ESP32 DevKit recommended)
- MCP2518FD CAN module wired per the pin table below
- USB cable (data-capable, not power-only)
- 120Ω resistor (optional — bench loopback test without a vehicle)
🚀 Quick Start Guide
1. First Launch
- Start the application (double-click
ESP32_CAN_Sniffer_OneFile.exe)
- Ensure your ESP32 is powered and connected
- Select connection type (Serial or WiFi)
- Click "Connect" to establish communication
2. Connection Setup
Serial Connection (USB)
- Connect ESP32 to your computer via USB cable
- Click "Refresh" to scan for available ports
- Select your ESP32 port (e.g., "COM3" on Windows)
- Set baudrate (default: 115200)
- Click "Connect"
WiFi Connection
- Connect your computer to the ESP32 WiFi network
- Network name: Usually "ESP32_CAN_Sniffer"
- Enter IP address (default: 192.168.4.1)
- Enter port (default: 82)
- Click "Connect"
3. Viewing Messages
- Raw Messages Tab: View all captured CAN messages in real-time
- Decoded Messages Tab: See decoded signals and values
- Statistics: Monitor message rates, buffer usage, and performance
📋 Most Used Features
Message Filtering
- Filter by CAN ID: Enter ID in the filter box
- Filter by data: Use hex or decimal format
- Clear filter: Click "Clear" button
Saving Sessions
- Click "Save Session" to save current capture
- Sessions are saved in JSON format
- Load sessions later for analysis or replay
Exporting Data
- Export to CSV: File → Export → CSV
- Choose raw or decoded messages
- Select date range if needed
Custom Labels
- Right-click on a CAN ID to add/edit label
- Labels help identify messages quickly
- Labels are saved in settings
🔧 Hardware Setup (ESP32 + MCP2518FD)
Pin Connections
| ESP32 Pin |
MCP2518FD Pin |
Description |
| 3V3 |
3V3 |
Controller logic (3.3V only — never 5V on this pin) |
| VIN |
5V |
Transceiver / module 5V rail (from ESP32 VIN when USB-powered) |
| GND |
GND |
Ground |
| GPIO18 |
SCK |
SPI Clock |
| GPIO19 |
SO (MISO) |
Master In Slave Out |
| GPIO23 |
SI (MOSI) |
Master Out Slave In |
| GPIO5 |
CS |
Chip Select |
| GPIO4 |
INT |
Interrupt (optional) |
⚠️ Critical: Wire 3V3 → 3V3 only for logic — do not connect 5V to the 3V3 pin. The separate module 5V pin should connect to ESP32 VIN (5V from USB) on typical breakouts.
Flashing ESP32 firmware (pre-compiled .bin)
- Unzip the firmware email attachment (20 MHz and 40 MHz builds included)
- Install Python 3 if needed, then run:
pip install esptool
- Find the ESP32 COM port in Device Manager (e.g.
COM4)
- 20 MHz MCP2518FD (most modules):
flash.bat COM4
- 40 MHz MCP2518FD only:
flash_40mhz.bat COM4
- Wait for “Done”, then unplug/replug USB and open the desktop app
Replace COM4 with your port. If flash fails, install CP210x/CH340 drivers and close any program using that COM port.
⚙️ Performance Tuning
- Buffer Size: Increase for longer captures (default: 10,000 messages)
- Update Rate: Adjust GUI refresh rate (default: 100ms)
- Baudrate: Increase serial speed for higher throughput (up to 1,000,000 bps)
🆘 Getting Help
Log file and debug output
The app writes a rotating log on your PC (even when the normal installer/EXE has no console window):
%LOCALAPPDATA%\ESP32_CAN_Sniffer\logs\can_sniffer.log
On most PCs that is:
C:\Users\<YourName>\AppData\Local\ESP32_CAN_Sniffer\logs\can_sniffer.log
Debug output (optional): In the main window, open the left panel under Highlighting and check Debug Output (Performance). Leave it off for normal use. When enabled, more detail is written to the log file above (the EXE does not open a separate debug window).
For support, use Help → About → Report Bug or email the log file (with debug enabled while reproducing the issue).