Complete USB2LPT6 photo
(The D-Sub connector is female.)

Keywords: USB, LPT, parallel, parallel port, printer port, converter, adaptor

To USB2LPT — Overview

USB2LPT – Cloning instructions for Release 1.6

This device is almost the same as Release 1.5.
For high-speed USB, there is a Release 1.7.

If 3.3V operation of ATmega is wanted, a user can now populate a dual diode BAV199 instead of the LD1117 of the previous version. This enables drawing less than 500 µA of standby current in this case.

The firmware from december 2010 to february 2012 is not compatible to Windows Vista and Windows 7 (32 and 64 bit) – please update!

Electronic Components

You need:

PiecesDescriptionReichelt Order CodePrice in € (2007)
1ATmega8 in TQFP32 packageATMEGA 8-16 TQ1.70
1Ceramic capacitor 100 nF 0603X7R-G0603 100n0.051
1Resistor array 220 Ω 1206BCN16 2200.02
1Resistor 10 kΩ 0805SMD-0805 10k0.10
1Electrolytic capacitor 10 µFrad 10/350.041
1Yellow LED 3 mm LED 3mm ge0.051
1SubD receptacle 25 pinD-SUB BU 250.15
1USB receptacle MiniB through-holeUSB BWM0.50
1HousingKappe CG25G0.13
1USB cable 1 mAK 673-A0.98
1Two-sided PCB (see below)UL16LP1.00

It's not hard to populate this PCB.

Photo upper side   Photo lower side
(Sufficiently) populated PCB


The yellow multi-function LED shows following states:


Here are some notes about firmware implementation:
The current USB2LPT Low-Speed (1.6) firmware implementation has many ways for I/O transaction. However, the driver (usb2lpt.sys) preferes only one, the oldest and still fastest way, using two BULK pipes. One BULK OUT for addresses and output (write) data, another BULK IN for input (read) data. Refer to DeviceIoControl() based API for understanding.

The other ways for I/O transactions exist for following reasons:



New: The do-it-yourself process for the similar 1.7 version is available at YouTube! (Three parts, running time ca. 30 minutes, German comments, English subtitling)
  1. Solder paste applying, SMD population
  2. SMD population (cont.), Reflow process, SubD receptacle
  3. USB receptacle, LED, Housing shell, Final check

Known PCB bugs

Solder jumpers

This revision 6 (USB2LPT 1.6) has 3 pre-connected solder jumpers: