HOW TO Poll the PS Cockpit Expanders

Since PS Cockpit Software V.0.9.7 and firmware version 1.6.0 you can poll the I/O expanders in three different ways:

-   PC Mode: In this mode PC is responsible to check all the boards in a given cycle.
-   Main Board: In this mode the Main Board will continuously poll the boards and send the values whenever they have changed. It will work better than the previous one.
-   Expander Interrupt: In this mode the expanders 16 and 40 I/O expanders their self are responsible to check it one of their inputs have changed and they will ask the Main Board to read the I/O expander.

The selection of the mode can be done in the USB Timers Page of the PS Cockpit Software:

While PC and Main Board modes run with no hardware modification, the Expander Interrupt mode needs an extra wire from the expanders to the Main Board.

The interrupt inputs of the Main Board are as follows:

The interrupt outputs of the expanders are the middle pin of the I2C connector:

As the interrupt outputs of the expanders are open drain active low outputs they need a pull-up resistor connected to 5V+. This can be easily accomplished by adding a 10K resistor to one of the expanders of the I2C daisy chain between the 5V+ pin and the interrupt pin:

You will need to add this resistor at least to one expander of each I2C channels.

One I2C channel will be look at follows:

The pcb's with the interrupt resistor already bult-in are TWP, TWA, X40, ELEC, AUDIO1&2 and TRIM. You don't need to add the resistor of the I2C channel where any of these pcb`s are located, just connect the interrupt input to the Main Board as shown above. 

Regards,

Shep