PS/2 & USB Keyboard Sniffer Adapter
The PS/2 & USB Sniffer adapter plank sits inline between a keyboard and a computer and passively records everything that crosses the wire. PS/2 and low speed USB are decoded live: raw packets scroll past as they happen, and a key tracker rebuilds the typed text right next to them, so you read words instead of scan codes.
PS/2 & USB Sniffer plank features:
- Two PS/2 (mini-DIN 6P) connectors and two USB connectors, wired as pass-throughs so the keyboard keeps working while you capture
- PS/2 scan code set 2 decoded to keystrokes
- Low speed USB HID boot protocol decoded to keystrokes
- A key tracker in each mode that reconstructs the typed text as a plain string
- TRIGGER output to sync an external logic analyzer to the capture
- PWR SWITCH to take bus power from the Bus Pirate VOUT supply or from the PC (EXT)
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Adapter pinout
| Bus Pirate pin | Label | Description |
|---|---|---|
| 1 | VOUT | Bus power, when the PWR SWITCH is in the VOUT position |
| 2 | TRIG | Trigger output to sync an external logic analyzer |
| 3 | D+ | USB D+ |
| 4 | D- | USB D- |
| 5 | RESV | Reserved |
| 6 | DAT | PS/2 data |
| 7 | CLK | PS/2 clock |
| 8 | RESV | Reserved |
| 9 | RESV | Reserved |
| 10 | GND | Common ground with the keyboard and the PC |
The Bus Pirate shows these same labels under the pin numbers in the status bar, so you can confirm the plank is wired the right way round at a glance.
Power switch
SW1 selects where the sniffed bus takes its power from. Slide it to VOUT to power the bus from the Bus Pirate supply, or to EXT to let the PC power it, exactly as it would without the plank in the way.
Both of the setups below need the PWR SWITCH in the EXT position, as in the photo. The keyboard is powered by the PC through the pass-through cables, not by the Bus Pirate.
Resources
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- Browse Complete Bus Pirate hardware collection
- Bus Pirate 5 REV10 with enclosure
- Probe Cable Kit
- Auxiliary Cable Kit
- Quick Connect Adapter
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