Taradov’s open-source hardware pocket USB sniffer works with Wireshark

Alex Taradov has designed a low-cost, open-source hardware USB sniffer compatible with the popular Wireshark packet capture utility, and also controllable from the command line, capturing data in the standard PcapNG format in either case.

Wireshark has had built-in USB capture capability for many years, and I used it myself to reverse-engineer the software for a USB video capture card around 2007, but it’s not perfect since it does not capture low-level packets. For that, you need extra hardware, and last year we covered the tinysniffer USB sniffer based on a WiFi-connected Linux SBC. It does the job, but it’s sold for $199, and you don’t need an application processor to handle USB 2.0 speeds. Alex’s design is optimized for cost and built around three main components: Cypress CY7C68013A 8051 MCU, Lattice MachXO2 LCMXO2 FPGA, and Microchip USB3343 USB PHY.

Taradov’s USB sniffer specifications:

• Microcontroller – Cypress CY7C68013A enhanced 8051 MCU @ 48 MHz with 16KB RAM, USB 2.0 (480 Mbps) support
• FPGA – Lattice MachXO2 LCMXO2-2000HC FPGA with 2,112 LUTs, 16.6 kbits distributed RAM, 74 kbits EBR SRAM; Speed grade 5/6 models are fine, Speed 4 is too slow
• USB PHY – Microchip USB3343 USB 2.0 ULPI transceiver
• USB ports
  • Right side (Target)
    • USB 2.0 Type-A port to connect the target device (e.g., flash drive, mouse…)
    • USB 2.0 Type-C port to connect to the target computer
  • Left side (Host) – USB 2.0 Type-C port to connect to the computer running Wireshark (it could be the target computer above, or another one).
• Misc
  • Power LED, 4x debug LEDs
  • 2-pin connector for “IO_IN”. Not sure what it is for (maybe a trigger pin?), and I can see some vendors do not include it.
• Power Supply – 5V via USB
• Dimensions – 59 x 38 mm

You’ll find all resources, including the KiCad schematics and PCB layout, MCU firmware, FPGA Verilog, and the Wireshark plugin (C code and pre-built binaries for Windows and Linux) on GitHub. While visiting taradov.com, I also noticed he worked on a “Lite” version based on the Raspberry Pi RP2040.

The USB sniffer project was first released about two years ago, but since it’s been released under a permissive BSD 3-Clause License that allows commercial use, a modified (or older) design can be found on AliExpress for $31.13 (board only) or $35.03 with an enclosure. This is the cheapest seller I could find, but if it is out of stock there, other vendors sell it too. You can also try to use discount coupons: CNX04USA for the US or CNX04W for the rest of the world (excluding most of Europe), or use other Black Friday/Cyber Monday 2025 coupons valid until December 3/4.

Thanks to fdd for the tip.

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