This adapter is based on the ATMega AT90USB1287 microcontroller. This uC can operate as USB device or host. I've set up the project with readily available parts that are still listed by the usual distributors like Digikey or Mouser. My PCB design can be found in the downloads section below in Gerber format.

Conceptually, this adapter is meant to keep compatibility to existing applications with respect to mouse movement and especially buttons. There is no need for a special driver to operate the three mouse buttons such that AmigaOS applications, NetBSD or Linux will work fully out of the box. This design choice means that the signals for the mouse wheel will be sent through the second DB9 port (Joystick port). While a two port design will not win an award for first glance elegance compared to 1 port solutions like Cocolino (serial transfer of extra information) or Micromys (analog extra information), there are some benefits towards compatibility (see above), robustness and required CPU resources. A second PCB containing an automatic switcher is part of this project in order to keep the option of Joystick connectivity. Hence, UWMouse consists of two parts: USB Mouse adapter and Joystick switch.

I'd suggest to start with the ATMega when building the PCB. There is not too much space around the uC and I've found it most convenient to populate it first. The minimal list of parts for uC programming consists of the ATMega, C1,C2,Y1 and R3 alongside the programming header J5. I've placed a circular mark on the silkscreen for correct placement of the ATMega. Please note that the images in this section show version 0.2/0.3 of the PCB. The later V0.4 has got three pins on J3 (W1,W2,+5V).

Next up are R1,R2,R4,R8,R9,C4 and the two LEDs. Please place the 100nF capacitors before soldering J1 and J2. Don't forget the two resistors on the bottom side. Else the LEDs won't work. R8/R9 should be either a solder blob or 0 Ohm resistors.

You may test the adapter without the DIP switches (just in case there are solder joints to correct). The DIP-Switches are supposed to enable optional features and won't be needed for initial tests.

When connecting a USB device, the red LED will glow for 2-3 seconds. After a mouse is detected and properly configured, the red LED will go off and the green LED is lit. Should the adapter run into issues with the format of the USB report mode, then it'll try to get into emergency (=USB boot) mode instead. In that case, both LEDs will be on. I am not aware of mice that need this special treatment (as of this writing).

J4 exposes the UART for debugging purposes. Please note that RX and TX of J4 are TTL level, hence you'd need a FT232R board, level shifters or similar to connect these to an RS232 port. The settings for the UART are 9600 8N1, no flow control, no hardware handshake.

The DIP switches are off by default. Their functions are as follows:

The Autojoy adapter is even easier to populate: start with the ATTiny, then add C1/R1 and the three connectors, done. Please pay attention to the location of the female connector on the PCB. The same applies to the male joystick connector. The silkscreen is marked accordingly.